Data channels menu

Overview

In the Data Channels menu, the user can manage its input channels and manipulate the hardware settings of the hardware modules.

*Data Channels* menu - quick view

Fig. 133 Data Channels menu - quick view

A single click on the Data Channels menu button will open the quick view where the user can see the activated hardware channels (see Fig. 133). Expanding the menu to the full screen by keeping the button pressed and moving the mouse to the opposite side of the screen will open the full data channel menu that can be seen in Fig. 134. The full channel list and the connected hardware with the individual settings can be checked and manipulated here. The functionality of the individual buttons will be explained in the following section.

Complete *Data Channels* menu

Fig. 134 Complete Data Channels menu

Table 7 Push buttons in the Channel Menu – Overview

No.

Name

Description

A - Hardware overview

Quick overview of your connected TRION boards and available channels. Click on a certain channel or whole TRION board and the respective channel(s) will be highlighted in the list.

B - Filter and grouping

1

Search Filter

Search a channel according to its name

2

Channel Filter

Filters the displayed channels according to their channel type (All, Analog, Digital, Counter, EPAD, Math, Video, Power, CAN)

3

Clear Filters

Clear active Channel and Search Filters

4

Channel Grouping

Sort the Channel list according to the connected TRION board or in an alphabetical order

C - Channel options

5

Select button

Select several channels in the list, i.e. for setting them active or inactive simultaneously.

6

Channel Name

Individual channel name; Can be changed individually; for additional information refer to UI options.

7

Color

Color scheme of the channel can be changed here

8

Hide button

Hide the channels of a complete card

9

Setup

Enter the input channel setup (All channel dependent settings can be changed here)

10

Active button

Set a channel active or inactive; An active channel can be displayed in an instrument, used in a math channel and can be recorded, an inactive channel not

11

Stored button

Select whether channel data shall be stored or not when a measurement is running

12

Scaled Value

Preview of the input signal

13

Mode

Change the mode of the input channel here

14

Sample Rate

Change the sample rate here; Remark: to change the sample rate for individual channels refer to Channel-wise Sample Rate Selector.

15

Range

Change the input range of the channel here

16

Scaling

Change the channel scaling here

17

Physical unit

Physical unit of the channel, can be changed in the channel setup

18

Advanced Options

Expand the channel dependent advanced Options: Excitation, LP Filter, Coupling, Input Type, Sample Format, Sensor Offset, Baud rate, Counter_Filter, Inverted_A, ListenOnly, Source_A, Termination, Threshold

19

Toggle button

Quick access to Data channels menu; toggles between the Channel List and the previously opened menu

D - Math options

20

Add button

Add a Formula, Statistics, Filter, FFT, Rosette, Power Group, Ethernet Receiver or Ethernet Sender

21

Delete button

Delete the Formula, Statistics, Filter, FFT, Rosette, Power Group, Ethernet Receiver or Ethernet Sender that is currently selected

22

Create Power Group

Create Power Group with selected channels or empty Power Group

Filter- and grouping options

Selecting multiple channels

Inside the Data Channels menu, the user can select multiple Input channels through various methods. With multiple channels selected, the user can address changes in Channel Settings to multiple channels at one time.

To select multiple channels:

  • Select a channel using the system graphic in the upper left-hand corner of the Data Channels menu

  • Select a check box on the left edge of the individual Data Channels menu adjacent to each individual channel

  • The user can also just simply click onto the channel row itself and select several channels by keeping the CTRL key pressed

Selecting Multiple Channels

Fig. 135 Selection of several channels

Note

It is also possible to Copy (CTRL+C) and Paste (CTRL+V) the settings between identical input channels

Channel List filtering options

As explained in Table 7, the user can filter the channels according to their channel type or their channel name, e.g. to only show relevant channels. There are additional filtering options available which are explained in the following sections.

To get to the different filter options in the channel list, fully open the Data Channel menu.

Filtering by the Channel Type

To filter the channels by their type different buttons are shown on the upper border of the channel list, shown in Fig. 136. These buttons vary depending on the available channels, meaning only those buttons are shown, for which the according channels are really available in the channel list.

Filtering by the *channel type*

Fig. 136 Filtering by the channel type

After choosing a type the button turns blue and only the according channels are shown.

Filtering by the *channel type*: Digital

Fig. 137 Filtering by the channel type: Digital

Note

Only one channel type can be selected, therefore, it is not possible to select more buttons at the same time.

Filtering Channels by Name/Active/Mode

Another option is to filter the channels by their names or mode or just to show active channels. Those filter options are shown by 3 dots in the column header (see Fig. 138).

Filter option available in Data Channel Menu

Fig. 138 Filter option available in Data Channel Menu

  • Fully open the Data Channels menu

  • Left click onto the column header opens a filter menu for: channel, active, mode

  • A sorting menu will appear for each filter menu, which allows the user to sort from A to Z, Z to A, by name/prefix such as AI or DI, or by true or false. Sorting by true or false will sort your channels by whether your channels or active (true) or inactive (false). The user can simply type a channel name within the menus text field. This may seem like a difficult task, but the software will automatically update the channel list as you type. Selecting a specific Mode name such as Temperature will only present the user with those specified channels.

  • Delete an active filter with the Clear filter button again (see ④ in Table 7)

    Filtering by the *Active* Column

    Fig. 139 Filtering by the Active Column

    Filtering by the *Channel* Column

    Fig. 140 Filtering by the Channel Column

    Filtering by the Mode Column

    Fig. 141 Filtering by the Mode Column

Changing the channel settings

It is either possible to change the channel settings in the Data Channels menu or in the individual channel setup that can be accessed via push button ⑫ (see Table 7).

Changing the channel settings in the Data Channel menu

To change the individual channel settings in the Data Channels menu that can be seen in 5‑2 just click on the desired parameter with the left mouse button and a pop-up window will appear. If a parameter can be changed or not depends on the channel type (i.e. it is not possible to change the range of a digital channel) and the selection of the parameters depends on the TRION board (i.e. different Input Modes). For illustration, the following figures will show the different options that are available with a TRION-1620-ACC board.

Changing the channel color

Pop-up window for changing the channel color

Fig. 142 Pop-up window for changing the channel color

Changing the input mode

Pop-up window for changing the input mode

Fig. 143 Pop-up window for changing the input mode

Changing the sample rate

Pop-up window for changing the sample rate

Fig. 144 Pop-up window for changing the sample rate

It is possible to change the sample rate for the whole board but also to change the sample rate channel-wise. For a detailed explanation see Sensor scaling – bridge.

Changing the input range

Pop-up window for changing the input range

Fig. 145 Pop-up window for changing the input range

Changing the channel scaling and physical unit

Pop-up window for changing the scaling and physical unit

Fig. 146 Pop-up window for changing the scaling and physical unit

Zeroing an input channel

After selecting the desired channel in the list the Zero push button will appear at the lower end of the Data Channels menu:

Zeroing an input channel

Fig. 147 Zeroing an input channel

Changing the sensitivity

Also available in the Channel Scaling pop-up window:

Pop-up window for changing the sensitivity

Fig. 148 Pop-up window for changing the sensitivity

Changing the 2-point-scaling

Also available in the Channel Scaling pop-up window:

Pop-up window for changing the 2-point-scaling

Fig. 149 Pop-up window for changing the 2-point-scaling

Applying table scaling

Also available in the Channel Scaling pop-up window:

Pop-up window for applying table scaling

Fig. 150 Pop-up window for applying table scaling

Changing the bridge scaling settings

Scaling setting for bridge mode

Fig. 151 Scaling setting for bridge mode

For more details about the sensor scaling for the bridge mode see Sensor scaling – bridge.

Changing the LP filter (Expand advanced settings)

Pop-up window for changing the LP filter

Fig. 152 Pop-up window for changing the LP filter

Note

When the sample rate is changed an appropriate filter will be selected automatically (Auto-mode).

Changing the coupling mode (Expand advanced settings)

Pop-up window for changing the coupling mode

Fig. 153 Pop-up window for changing the coupling mode

Changing the bit resolution (Expand advanced settings)

Can only be changed for the whole board and not for single channels:

Pop-up window for changing the bit resolution

Fig. 154 Pop-up window for changing the bit resolution

Channel-wise Sample Rate Selector

To change the sample rate of whole module simply click on one of the sample rates of a channel of that module and select the desired sample rate from the Sample rate drop-down list (see Fig. 155).

Selection of the sample rate of a TRION module with the drop-down list

Fig. 155 Selection of the sample rate of a TRION module with the drop-down list

To change the sample rate just for an individual channel, click on the Enable reduction button in the Sample Rate window (see Fig. 156). The target rate can then be selected from the drop-down list. There is a selection of different sample rates available for an individual channel as integer divisors down to 1/1000th of the sample rate of the module. It is not possible to enter a sample rate, only to select one from the drop-down list.

For example, if the sample rate of the module is selected as 20 kHz, the smallest available sample rate for a channel on that module is 20 Hz.

Note

The smallest available reduction is 1 Hz. If the sample rate of the module is 100 Hz, the smallest reduction for a channel is 1 Hz.

Selection of a sample rate for an individual channel

Fig. 156 Selection of a sample rate for an individual channel

In case the sample rate of the module will be changed, whenever a reduction is active, the target rate stays the same if it is still an integer divisor of the new sample rate of the module. This also means that only a reduction of the module sample rate is possible.

Example The sample rate of the module is set to 500 kHz and Channel 2 is set to a reduced sample rate of 20 kHz. The sample rate of the module is now changed to 100 kHz, and the target rate of Channel 2 stays at 20 kHz, since this is also an integer divisor of 100 kHz.

In case the target rate does not fulfill this requirement when the sample rate of the module is changed, if i.e. the sample rate is smaller than the reduced rate of a channel, the effective rate is shown in red below the target rate seen in Fig. 157. The effective rate is chosen to be as close as possible to the original selected target rate, which is still possible with the new sample rate of the module. With the Accept button this effective rate will be used as the new target rate of the channel.

Effective sample rate when changing the sample rate of the module

Fig. 157 Effective sample rate when changing the sample rate of the module

In case this suggested effective rate is not accepted by clicking the button, the effective rate is shown in red in the channel list (see Fig. 158). The originally selected target rate is shown in brackets below. Even though the effective rate was not accepted, it will still be used as new target rate for this channel. The red marking solely serves as an indication for this.

Not accepted effective rate as reduced sample rate in the channel list

Fig. 158 Not accepted effective rate as reduced sample rate in the channel list

Information

  • The channel-wise sample rate selector is also applicable with formula channels

  • The frequency of the AUTO-Filter will be adjusted automatically with the new sample rate

Working principle

This chapter shortly explains the working principle behind the channel-wise sample rate selector. The samples are physically sampled with the set sample rate, which is defined in the channel list (red box in Fig. 159). If the reduction is enabled the user can set a reduced sample rate (blue box in Fig. 159) which is converted to an integer divider in the background and unnecessary samples are skipped

Channel-wise sample rate settings

Fig. 159 Channel-wise sample rate settings

If the filter settings are set on AUTO, the filter is adjusted according to the target sample rate, therefore, the user must not worry about aliasing. In the exemplary settings above, the filter would be set automatically to 3333.3 Hz for this channel. However, the user can override the filter settings if needed.

Working principle for the channel-wise sample rate reduction

Fig. 160 Working principle for the channel-wise sample rate reduction

Example

In Fig. 161 exemplary signals with and without sample rate reduction and with different filter settings can be seen. The different signals have the following settings:

  • Blue signal - Sample rate: 200 kS/s - Filter setting: AUTO

  • Red signal - Reduced sample rate: 10 kS/s - Filter setting: AUTO

  • Green signal - Reduced sample rate: 10 kS/s - Filter setting: 66666.6 Hz

Channel-wise sample rate reduction with example signals

Fig. 161 Channel-wise sample rate reduction with example signals

The red signal is phase-shifted due to the anti-aliasing filter, which is automatically set to 3333.3 Hz. The green signal also has a reduced sample rate and a manual set filter, according to the auto filter setting of the blue signal. Therefore, those two signals are not phase-shifted. In this case, the user must be aware of aliasing.

Table scaling

OXYGEN offers the possibility to apply non-linear scaling in form of a table for non-linear sensors. This can be done in the data channel menu but also in the channel settings of an individual channel.

Following options are available:

  • The unit can be specified

  • Individual points to specify x- and y-values can be added by clicking on the + button (see Fig. 159)

  • A point can be removed by clicking on the button (see Fig. 160)

    Table scaling – add point to specify x- and y-value

    Fig. 162 Table scaling – add point to specify x- and y-value

    Table scaling – delete point

    Fig. 163 Table scaling – delete point

  • By clicking the AVG or the AC RMS button, a direct measurement point at the current instant of time can be added to the table.

  • A table can also be copied from another source, e.g. Excel and pasted with CTRL+V or the Paste button into the table scaling menu. Likewise, the table can be copied using CTRL+C or the Copy button and pasted into e.g. Excel (see Fig. 161).

image3image4

  • To copy and paste a whole table from one channel to another the Copy button in channel 1 can be used. After entering the channel settings of channel 2, the Paste button can simply be clicked on, and the table will also be applied here.

Note

  • For a valid scaling, at least two points have to be added, otherwise an error message will appear.

  • If duplicate x-values exist in the table, an error message will appear.

  • If a value is out of the defined table range the scaling will be extrapolated.

  • Linear interpolation is applied between the table points.

  • The x-values do not necessarily have to be entered from lowest to highest value, since the table will be sorted when leaving and entering the menu again.

  • As it is also noted in Selecting multiple channels, the whole channel settings, including the table scaling, can be copied and pasted between different channels using CTRL+C and CTRL +V.

Sensor scaling – bridge

The following section gives a small overview about the scaling setting for different bridge configurations. For a detailed explanation about this topic refer to further literature.

The following definitions are used for the equations:

Ri … Strain gage resistor of the bridge

UD … Bridge output voltage

UIN … Bridge supply voltage

ε … Elongation

k … Bridge factor

ν … Poisson’s ratio

Quarter bridge

Used to measure tension and compression

Table 8 Quarter bridge

Schematic

UD / UIN equation

Bridge factor

Linearity

Active strain gauges

image5

Formel

1

No

One active strain gauge (R1)

Half bridge

Used to measure bending

Table 9 Half bridge - bending

Schematic

UD / UIN equation

Bridge factor

Linearity

Active strain gauges

image6

Formel

2

Yes

Two active strain gauges (R1 and R2). The elongation of R1`and R:sub:`2 must be the same but opposite in sign, i.e. one strain gage can be put on top of a beam and the other on the bottom.

Used to measure tension and compression

Table 10 Half bridge - tension and compression

Schematic

UD / UIN equation

Bridge factor

Linearity

Active strain gauges

image7

Formel

(1 + v)

Yes

Two active strain gauges (R1 and R´2). 1x longitudinal elongation / 1x transverse elongation. One strain gauge lies in principal and the other in transverse direction.

Full bridge

Used to measure bending

Table 11 Half bridge - bending

Schematic

UD / UIN equation

Bridge factor

Linearity

Active strain gauges

image8

Formel

2 x (1 + v)

Yes

Four active strain gauges (R1, R2, R3 and R4). The elongation of all strain gauges is the same in magnitude; the elongation of R1`and R:sub:`3 are opposite to the elongation of R2`and R:sub:`4.

Used to measure tension and compression

Table 12 Half bridge - tension and compression

Schematic

UD / UIN equation

Bridge factor

Linearity

Active strain gauges

image9

Formel

2 x (1 + v)

No

Four active strain gauges (R1, R2, R3 and R4); 1x longitudinal elongation, 2x transverse elongation. One pair of strain gauges lies in principal and the other pair in transverse direction.

Changing the channel settings in the channel setup

All channel settings (except the sample rate and the bit resolution) can also be changed in the individual Channel Setup (see Fig. 164) which can be accessed via push button ⑪ (see Fig. 134 or Table 7).

Channel setup of a TRION-1620-ACC channel

Fig. 164 Channel setup of a TRION-1620-ACC channel

The main advantage compared to the parameter manipulation in the Data channels menu is that a wide preview window is available. With that, the user can see the affection of different parameter changes (i.e. range and scaling) on the input signal in real time. To swap between the channel setups of different channels use the arrows (<< >>) in the upper right corner and to close the channel setup use the X next to the arrows.

Current measurement using TRION modules

Different TRION modules can be used for current measurement. Current signals can be connected directly to TRION-1603-LV-6-L1B, TRION-1620-LV-6-L1B and TRION-1620-ACC-6-L1B modules and measure the current via an integrated 10 Ω shunt resistor.

Other modules can also be used for current measurements but need an external shunt resistor to support this functionality. These modules are the following: TRION-1603-LV-6-BNC, TRION-1620-LV-6-BNC, TRION-1620-ACC-6-BNC, TRION-1820-dLV, TRION-1600-dLV and TRION-2402-x. The TRION-1820-PA module is excluded from this consideration.

Modules that require an external shunt resistor for the current measurement contain a predefined shunt resistor selection in the Channel List (see Fig. 165) if Current Amplifier Mode is selected.

External Shunt resistor selection in the Channel Setup

Fig. 165 External Shunt resistor selection in the Channel Setup

From the technical point of view, the current measurement via an (external) shunt resistor is the measurement of the potential difference that is caused by the current on the shunt resistor.

I = \frac{U}{R}

The voltage U is measured, the resistance R is known and therefore the Current I can be determined. Thus, if the current is measured via an external shunt, a voltage signal representing the potential difference caused by the current on the external shunt is provided to the TRION-module. This voltage is rescaled to the current again by using the formula above. This rescaling is done by OXYGEN. Therefore, the resistance must be known and can be selected in the drop-down list from Fig. 165.

For sure, any shunt resistor can be used and not the ones contained in the drop-down list. If a shunt is used whose resistance is not contained in the list, the rescaling of the voltage signal representing the current can be done manually in Voltage Amplifier mode proceeding the following steps:

  • Set the Amplifier Mode to Voltage (see Fig. 166):

Voltage measurement mode

Fig. 166 Voltage measurement mode

  • Change the Unit to A(mpere) and enter the resistance of the shunt resistor as Scaling factor, i.e. 50 Ω (see Fig. 167).

Entering the shunt resistance as scaling factor

Fig. 167 Entering the shunt resistance as scaling factor

  • With these settings, the rescaling of the voltage signal to the represented current is done in the same manner as in Current mode with the corresponding shunt resistor selected in the drop-down list. Thereby, the voltage signal is multiplied with the entered Scaling factor and the result of this equation is the corresponding current:

    \text{corresponding\ current\ I} = scaling\ factor\ R*measured\ voltage\ U

  • Considering the physical units of this equation will clarify that:

    \lbrack A\rbrack = \left\lbrack \frac{A}{V}*V \right\rbrack

If a TRION module with integrated 10 Ω shunt is used for the current measurement, this consideration can be neglected! This applies only for current measurements via external shunt resistors.

Mathematical channels

OXYGEN enables the user to easily create Formula (see Formula channel), Statistics (see Statistics channel), Filters (see Filter channel), FFT (see FFT channels) or (Strain gauge) Rosette channels (see Rosette (strain gauge) channels) which are calculated in real time. For details about the Psophometer calculation, refer to Psophometer. The Swept sine Analysis calculation is explained in Swept Sine Analysis.

To create a new channel, the user needs to click on the Add button in the lower left corner (marked red in :numref: creation_math_channel) and a pop-up window will appear where the user can select if he wants to create a Formula, Statistics, Filter channel, a FFT or Rosette calculation. If a Statistics or Filtering channel or a FFT or Rosette calculation shall be created, the user must select the desired input channel(s) in the Channel List before clicking on the Add button. The created channels will show up in the Math channel section in the Data Channels menu.

Creation of a math channel

Fig. 168 Creation of a math channel

Note

The Calculation Setup stores the information if a Formula, a Statistics or a Filtering channel was created lastly and selects the respective one automatically when the window is opened the next time.

Basic math

Formula channel

For creating a Formula math channel, the user must click on the Add button in the lower left corner (marked red in Fig. 168) and select Formula (see Fig. 169).

Pop-up window for creating a Formula channel

Fig. 169 Pop-up window for creating a Formula channel

Formula channel setup - overview

Fig. 170 Formula channel setup - overview

Table 13 Push buttons in the formula channel setup – overview

No.

Name

Description

1

Active button

Setting a channel active or inactive; An active channel can be displayed in an instrument, used in a math channel and can be recorded, an inactive channel not

2

Channel name

Individual channel name; Can be changed individually

3

Physical unit

Physical unit of the channel, can be changed in the channel setup

4

Command line

Type your desired formula here

5

Add button

Adds the individual channel to the command line; Channels can be added to the command line by drag and drop, too

6

Functions

Available mathematical and logical functions can be selected here. Using the back (a) and forward (b) buttons the user can swap between Standard, Trigonometric, Logic and Miscellaneous functions. For a description and the correct syntax of the individual functions, refer to Mathematical and logical functions.

7

Keys and Operators

Numerical pad and mathematical operators; Can also be entered via the keyboard.

8

Preview window

Real Time preview of the calculation

Note

It is possible to assign channels with different sample rates to one formula channel. The sample rate of the formula channel will be set to the highest input channel sample rate. The samples of channels with lower sample rates will not be interpolated, but the last value will be repeated according to the fastest sample rate until the channel is updated.

Mathematical and logical functions
Table 14 Standard mathematical operators - description and syntax

Function

Description

Syntax

e

Euler’s number

e

π

Constant Pi

pi

min

Minimum of two values

min(x,y)

max

Maximum of two values

max(x,y)

abs

Absolute value

abs(value)

x^y

Exponential function with arbitrary basis

pow(x,y)

e^

Exponential function with basis e

exp(x)

2^

Exponential function with basis 2

exp2(x)

ln

Natural logarithm to basis e

ln(x)

log

Common logarithm to basis 10

log(x)

Square root

sqrt(x)

Cube root

cbrt(x)

Table 15 Trigonometrical operators - description and syntax

Function

Description

Syntax

sin

Sine

sin(x)

asin

Arc sine

asin(x)

sinh

Hyperbolic sine

sinh(x)

asinh

Arc hyperbolic sine

asinh(x)

cos

Cosine

cos(x)

acos

Arc cosine

acos(x)

cosh

Hyperbolic cosine

cosh(x)

acosh

Arc hyperbolic cosine

acosh(x)

tan

Tangent

tan(x)

atan

Arc tangent

atan(x)

tanh

Hyperbolic tangent

tanh(x)

atanh

Arc hyperbolic tangent

atanh(x)

Table 16 Logical operators - description and syntax

Function

Description

Syntax

<

If ‘value1’ is less than ‘value2’, the result is 1.0 else 0.0

value1 < value2

If ‘value1’ is less than or equals ‘value2’, the result is 1.0 else 0.0

value1 <= value2

>

If ‘value1’ is greater than ‘value2’, the result is 1.0 else 0.0

value1 > value2

If ‘value 1’ is greater than or equals ‘value 2’, the result is 1.0 else 0.0

value1 >= value2

=

If ‘value 1’ equals ‘value 2’, the result is 1.0 else 0.0 (Two NaNs do not compare equal

value1 == value2

If ‘value 1’ is different than ‘value 2’, the result is 1.0 else 0.0

value1 != value2

and

Logic and: value1 != 0.0 and value2 != 0.0 → 1.0 value1 = 0.0 and value2 != 0.0 → 0.0 value1 != 0.0 and value2 = 0.0 → 0.0 value1 = 0.0 and value2 = 0.0 → 0.0

value1 and value2

or

Logic or: value1 != 0.0 or value2 != 0.0 → 1.0 value1 = 0.0 or value2 != 0.0 → 1.0 value1 != 0.0 or value2 = 0.0 → 1.0 value1 = 0.0 or value2 = 0.0 → 0.0

value1 or value2

not

Logic negation: If value = 0.0, the result is 1.0, else 0.0

not value

if

If condition is true, the result is ‘true_val’, otherwise ‘false_val’

if(condition,true_val,false_val)

isnan

If value is NaN, result is 1.0, 0.0 otherwise

isnan(value)

Table 17 Measurement functions – description and syntax

Function

Description

Syntax

ecnt1

Count number of edges on condition; condition is mandatory, rearm and reset parameter optional

ecnt(cond,rearm,reset)

hold2

Hold value at trigger condition; value and condition parameters are mandatory, init and rearm optional

hold(value,cond,init,rearm)

stopwatch3

Measure the timespan between two conditions in seconds; start and stop condition is both mandatory, reset is optional

stopwatch(start_cond,stop_cond, reset)

measdiff4

Measure the value difference of one channel between two conditions

measdiff(val,cond1,cond2)

period5

Measure the period duration in seconds between consecutive conditions with optional rearm condition

Edge(cond,rearm)

dutycycle6

Measure the dutycycle (from 0 to 1) between consecutive conditions with optional rearm condition

Dutycycle(cond,rearm)

edge7

Generate positive edge on cond with rearm condition

Edge(cond,rearm)

rmin8

Measure rolling overall minimum of a channel during a measurement with optional reset condition

rmin(value,reset)

rmax8

Measure rolling overall maximum of a channel during a measurement with optional reset condition

rmax(value,reset)

ravg8

Measure rolling overall average of a channel during a measurement with optional reset condition

ravg(value,reset)

rrms8

Measure rolling overall RMS of a channel during a measurement with optional reset condition

rrms(value,reset)

rsum8

Measure rolling overall sum of a channel during a measurement with optional reset condition

rsum(value,reset)

racrms8

Measure rolling overall ACRMS of a channel during a measurement with optional reset condition; Not included in the selection and must be typed manually

racrms(value,reset)

rp2p8

Measure rolling overall Peak-to-Peak of a channel during a measurement with optional reset condition; Not included in the selection and must be typed manually

Rp2p(value,reset)

Legend to Table 17

Table 18 Miscellaneous operators - description and syntax

Function

Description

Syntax

time1

Returns the elapsed time since acquisition (re)start in seconds

time

mtime1

Returns the elapsed time since measurement star in secondst

mtime

scnt1

Counts the number of samples since acquisition (re)start

scnt

sr1

Returns the Sample Rate in Hz

sr

mod

Remainder of division x/y, sign of x

mod(x,y)

noise

Creates Noise signal in the range [-x…+x]

noise(x)

atan2

Arc tangent of y/x using signs of arguments to determine the correct quadrant

atan2(y,x)

floor

Rounds x towards minus infinity

floor(x)

ceil

Rounds x towards plus infinity

ceil(x)

round

Round to nearest integer

round(x)

trunc

Round x towards zero

trunc(x)

1A channel to which the function refers must be specified, i.e. in the following manner: ‘Ref_Ch’ * 0 + time

Edge-count function (ecnt)

Syntax: ecnt(cond,rearm,reset)

The Edge-count function counts the number of fulfilled conditions. If desired, a Rearm event which must be passed before a condition can be fulfilled again, can be defined. A Reset event can be defined optionally, too. Condition, Rearm and Reset can be applied to Rising and Falling signal edges. Rising Edges can be defined by using the logical operators > and . Falling Edges can be defined by using the logical operators < and ≤.

The following examples will explain the functionality (corresponding dmd-file can be found here: https://ccc.dewetron.com/pl/OXYGEN):

ECNT_Cond = ecnt(‘SIGNAL’>800)

Every time the channel SIGNAL passes 800 with a Rising Edge (>), the channel ECNT_Cond increases by 1 (see Fig. 171).

The reason why the ecnt-function increases by more than 1 in Fig. 171 is that the signal is floating around the Condition level several times due to noise. This can be seen in the magnification in Fig. 171. This is also the reason why the ecnt-function counts on Falling Edges as well. To avoid disturbed results caused by signal noise, a Rearm Level can be defined. A suitable example can be found in the following section and in Fig. 172.

ECNT-function with *Cond*\ ition only

Fig. 171 ECNT-function with Condition only

ECNT_Cond_Rearm = ecnt(‘SIGNAL’>800,’SIGNAL’<500)

If the channel SIGNAL passes 800 with a Rising Edge (>), the channel ECNT_Cond_Rearm increases by 1. To avoid unwanted increments caused by noise on the signal, the channel SIGNAL must pass 500 with a Falling Edge (<) before the channel ECNT_Cond_Rearm counts again when the channel SIGNAL passes 800 with a Rising Edge (>) (see Fig. 172).

ECNT-function with *Cond*\ ition and *Rearm*

Fig. 172 ECNT-function with Condition and Rearm

ECNT_Cond_Rearm_Reset = ecnt(‘SIGNAL’>800,’SIGNAL’<500,’SIGNAL’<-100)

If the channel SIGNAL passes 800 with a Rising Edge (>), the channel ECNT_Cond_Rearm_Reset increases by 1. To avoid unwanted increments caused by noise on the signal, the channel SIGNAL must pass 500 with a Falling Edge (<) before the channel ECNT_Cond_Rearm_Reset counts again when the channel SIGNAL passes 800 with a Rising Edge (>). If the Channel SIGNAL passes -100 with a Falling Edge (<), the channel ECNT_Cond_Rearm_Reset is set to 0 (see Fig. 173).

ECNT-function with *Cond*\ ition, *Rearm* and *Reset*

Fig. 173 ECNT-function with Condition, Rearm and Reset

Hold function (hold)

Syntax: hold(value,cond,init,rearm)

The hold-function requires two input channels. One channel is the Signal channel and one channel the Condition channel. If the Condition channel fulfills a certain Condition, the actual value of the Signal channel is stored to the hold-function channel. If desired, an Initial value and a Rearm event which must be passed before a Condition can be fulfilled again, can be defined. Condition and Rearm can be applied to Rising and Falling signal edges. Rising Edges can be defined by using the logical operators > and . Falling Edges can be defined by using the logical operators < and ≤.

The following examples will explain the functionality (corresponding dmd-file can be found here: https://ccc.dewetron.com/pl/OXYGEN):

HOLD_VAL_COND = hold(‘SIGNAL_VAL’,’SIGNAL_COND’>5)

If the channel SIGNAL_COND passes 5 with a Rising Edge (>), the actual value of the channel SIGNAL_VAL is stored to the channel HOLD_VAL_COND. The value of the channel HOLD_VAL_COND is NaN before reaching the Condition the first time (see Fig. 174).

HOLD function with *Cond*\ ition

Fig. 174 HOLD function with Condition

HOLD_VAL_COND_INIT = hold(‘SIGNAL_VAL’,’SIGNAL_COND’>5,2)

If the channel SIGNAL_COND passes 5 with a Rising Edge (>), the actual value of the channel SIGNAL_VAL is stored to the channel HOLD_VAL_COND_INIT. The Initial value of the channel HOLD_VAL_COND_INIT is 2 before reaching the Condition the first time (see Fig. 175).

HOLD function with *Cond*\ ition and *Init*\ ial value

Fig. 175 HOLD function with Condition and Initial value

HOLD_VAL_COND_INIT_REARM = hold(‘SIGNAL_VAL’,’SIGNAL_COND’>5,2,’SIGNAL_VAL’>-3)

If the channel SIGNAL_COND passes 5 with a Rising Edge (>), the actual value of the channel SIGNAL_VAL is stored to the channel HOLD_VAL_COND_INIT_REARM. The Initial value of the channel HOLD_VAL_COND_INIT_REARM is 2 before reaching the Condition the first time. In addition, the channel SIGNAL_VAL must pass -3 with a Rising Edge (>) before the channel HOLD_VAL_COND_INIT_REARM updates again when the channel SIGNAL_COND passes 5 with a Rising Edge (>) (see Fig. 176).

HOLD function with *Cond*\ ition, *Init*\ ial value and *Rearm* level

Fig. 176 HOLD function with Condition, Initial value and Rearm level

Stopwatch function (stopwatch)

Syntax: stopwatch(start_cond,stop_cond, reset)

Schematic explanation of the stopwatch function

Fig. 177 Schematic explanation of the stopwatch function

The stopwatch function returns the timespan in seconds between two conditions (start_cond and stop_cond). Both conditions may refer to the same channel or to different channels. An optional reset condition resets the stopwatch function to NaN until the next start_cond occurs.

  • If the reset is not specified, the stopwatch-function restarts to count at 0s automatically at every new start_cond.

  • If the reset is specified as 0 (i.e. stopwatch (start_cond,stop_cond,0)), the stopwatch function does not restart to count at 0s when a new start_cond occurs but continues counting from the last value.

  • If the reset is specified differently, i.e. as signal<0, the stopwatch function is reset to NaN if this certain event occurs and starts counting from 0s if a new start_cond occurs.

  • If the start_cond appears again before a stop_cond is reached, the start_cond will be ignored.

  • If start_cond is equal to the stop_cond, the stopwatch returns 0s.

The following examples will clarify the functionality of the stopwatch function (corresponding dmd-file can be found here: https://ccc.dewetron.com/pl/OXYGEN):

STOPWATCH_cond1_cond2 = stopwatch(‘SIGNAL1’>100,’SIGNAL1’>800)

The stopwatch function (dark blue graph in Fig. 178) will start to measure the time in seconds if the channel SIGNAL1 (light blue graph in Fig. 178) exceeds 100 and stop to measure the time in seconds if the channel SIGNAL1 exceeds 800. If SIGNAL1 will exceed 100 again, the stopwatch function restarts to measure at 0s.

Stopwatch with start and stop condition

Fig. 178 Stopwatch with start and stop condition

STOPWATCH_cond1_cond2_0 = stopwatch(‘SIGNAL1’>100,’SIGNAL1’>800,0)

The stopwatch function (pink graph in Fig. 179) will start to measure the time in seconds if the channel SIGNAL1 (light blue graph in Fig. 179) exceeds 100 and stop to measure the time in seconds when the channel SIGNAL1 exceeds 800. If SIGNAL1 will exceed 100 again, the stopwatch function restarts to measure from the last value and NOT reset.

Stopwatch with start and stop condition, no reset

Fig. 179 Stopwatch with start and stop condition, no reset

STOPWATCH_cond1_cond2_reset = stopwatch(‘SIGNAL1’>100,’SIGNAL1’>800,’SIGNAL1’<-100)

The stopwatch function (green graph in Fig. 180) will start to measure the time in seconds if the channel SIGNAL1 (light blue graph in Fig. 180) exceeds 100 and stop to measure the time in seconds when the channel SIGNAL1 exceeds 800. If (and only if) SIGNAL1 decreases below -100, the stopwatch function will reset to NaN and restart to measure from 0s if SIGNAL1 exceeds 100 again.

Stopwatch with start and stop condition, reset specified

Fig. 180 Stopwatch with start and stop condition, reset specified

Measdiff function (measdiff)

Syntax: measdiff(val,cond1,cond2)

The measdiff function returns the value difference between cond1 and cond2 of the signal val. The three parameters may refer to same channel or each to a different channel.

The measdiff function will return NaN before cond2 is reached for the first time.

  • If cond1 and cond2 are triggered several times during one measurement, the measdiff function will be updated after cond2 is reached again.

  • If cond1 is reached several times before cond2 is reached, the measurement will start when cond1 is reached for the first time and will not be reset if cond1 is reached again.

The following examples will clarify the functionality of the measdiff function (corresponding dmd-file can be found here: https://ccc.dewetron.com/pl/OXYGEN):

MEASDIFF_val_cond1_cond2 = measdiff(‘SIGNAL2’,’SIGNAL1’>100,’SIGNAL1’>800)

The measdiff function (purple graph in Fig. 181) will measure and return the value difference of SIGNAL2 (green graph in Fig. 181) triggered by the following conditions: The measurement is initialized when SIGNAL1 (light blue graph in Fig. 181) exceeds 100 and stopped when SIGNAL1 exceeds 800.

Measdiff function

Fig. 181 Measdiff function

Period function (period)

Syntax: period(cond,[rearm])

The period function returns the period time of a signal in seconds. The signal to which the function shall be applied to must be specified in the cond in combination with the period threshold which is normally zero.

An optional rearm level will suppress distortion caused by signal noise. The rearm can be applied to the same or to a different signal.

The following examples will clarify the functionality of the period function (corresponding dmd-file can be found here: https://ccc.dewetron.com/pl/OXYGEN):

PERIOD_cond = period(‘SIGNAL’>0)

The period function (green graph in Fig. 182) will measure and return the period time of SIGNAL (brown graph in Fig. 182) for the condition that the SIGNAL level is higher than 0. As the SIGNAL is a pure sine wave with frequency 0.5 Hz, its period time should be 2 seconds. But due to noise on the signal, the zero-level is crossed several times (see Fig. 183) and causes a wrong measurement result when determining the period time. To suppress the influence of noise on the period time determination, a rearm level can be optionally added. This is explained in the next section.

PERIOD_cond_rearm = period(‘SIGNAL’>0,’SIGNAL’>-5)

The period function (green graph in Fig. 182) will measure and return the period time of SIGNAL for the condition that the SIGNAL level is higher than 0. As period time measurements can be disturbed by noise, a rearm level is added in this example to avoid the influence of noise to the signal. The rearm level is set to the following condition: The level of the SIGNAL must exceed -5. This means that the SIGNAL must exceed -5 before the condition SIGNAL>0 is detected again. With this optional rearm level the influence of noise on the period time measurement that can be seen in the green graph of Fig. 182 is suppressed and the detected period time is always 2s as it can be seen in the blue graph of Fig. 182.

Period function

Fig. 182 Period function

Noise disturbing the correct functionality of the period determination

Fig. 183 Noise disturbing the correct functionality of the period determination

Dutycycle function (dutycylce)

Syntax: dutycylce(cond,[rearm])

The dutycycle function returns the dutycycle of a signal. The signal to which the function shall be applied to must be specified in the cond in combination with the dutycylce threshold.

An optional rearm level will suppress distortion caused by signal noise. The rearm can be applied to the same or to a different signal.

The following examples will clarify the functionality of the dutycycle function (corresponding dmd-file can be found here: https://ccc.dewetron.com/pl/OXYGEN):

DUTYCYCLE_cond = dutycycle(‘SIGNAL’>0)

The dutycylce function (orange graph in Fig. 184) will measure and return the dutycycle of SIGNAL (brown graph in Fig. 184) for the condition that the SIGNAL level is higher than 0. As the SIGNAL is a pure sine wave, its duty cycle should be 0.5 (or 50%). But due to noise on the signal, the zero-level is crossed several times (see Fig. 185) and causes a wrong measurement result when determining the dutycycle. To suppress the influence of noise on the dutycycle determination, a rearm level can be optionally added. This is explained in the next section.

DUTYCYCLE_cond_rearm = dutycycle(‘SIGNAL’>0,’SIGNAL’>-5)

The dutycylce function (orange graph in Fig. 184) will measure and return the dutycycle of SIGNAL for the condition that the SIGNAL level is higher than 0. As dutycycle measurements can be disturbed by noise, a rearm level is added in this example to avoid the influence of noise to the signal. The rearm level is set to the following condition: The level of the SIGNAL must exceed -5. This means that the SIGNAL must exceed -5 before the condition SIGNAL >0 is detected again. With this optional rearm level the influence of noise on the dutycylce measurement that can be seen in the orange graph of Fig. 185 is suppressed and the detected dutycycle is always 0.5 (50%) as it can be seen in the blue graph of Fig. 185.

Dutycycle function

Fig. 184 Dutycycle function

Noise disturbing the correct functionality of the dutycycle determination

Fig. 185 Noise disturbing the correct functionality of the dutycycle determination

Edge function (edge)

Syntax: edge(cond,rearm)

The edge function returns a rising egde from 0 to 1 in case the condition is passed and a falling edge from 1 to 0 if the rearm is passed.

The following examples will clarify the functionality of the edge function (corresponding dmd-file can be found here: https://ccc.dewetron.com/pl/OXYGEN):

EDGE_cond_ream = edge(‘SIGNAL’>800, ‘SIGNAL’<-100)

The edge function (green graph in Fig. 186) will return a rising edge from 0 to 1for the condition that the SIGNAL level exceeds 800 (brown graph in Fig. 186). In case the SIGNAL falls below -100, the edge function will return a falling edge from 1 to 0.

Edge function

Fig. 186 Edge function

Combination of edge function and other formulas

In case a formula that does not contain a rearm level as optional parameter, such as the stopwatch function (see Stopwatch function (stopwatch)) or the measdiff function (see Measdiff function (measdiff)), the edge function (see Edge function (edge)) can be used to generate this rearm level.

The following example will clarify the functionality by demonstration the combination of the edge and stopwatch function (corresponding dmd-file can be found here: https://ccc.dewetron.com/pl/OXYGEN):

The blue signal in Fig. 187 will measure the time using the stopwatch between the following two conditions: cond1 is true if SIGNAL1 (green signal in Fig. 187) exceeds 100. Cond2 is true if SIGNAL1 (green signal in Fig. 187) exceeds 800.

The formula syntax of the blue signal in Fig. 184 is the following:

stopwatch(‘SIGNAL1’>100,’SIGNAL1’>800)

Due to noise, cond1 is passed several times which might be undesired. To suppress this influence of noise a rearm level of -100 can be added for cond1 by using the edge function. The result can be seen in the orange graph of Fig. 187. In this example, the stopwatch function is only restarted if SIGNAL1 falls below -100.

The syntax is the following:

stopwatch(edge(‘SIGNAL1’>100,’SIGNAL1’<-100)>0.5,’SIGNAL1’>800)

Combination of edge and stopwatch function

Fig. 187 Combination of edge and stopwatch function

Rolling-overall-functions

rmin(value[,reset])

Returns the global minimum of the signal specified as value from acquisition start until the current instant of time; Is reset at measurement start; Can be optionally reset by specifying a reset condition; The update rate is equal to the sample rate of the channel with the highest sample rate that is assigned to this formula.

rmax(value[,reset])

Returns the global maximum of the signal specified as value from acquisition start until the current instant of time; Is reset at measurement start; Can be optionally reset by specifying a reset condition; The update rate is equal to the sample rate of the channel with the highest sample rate that is assigned to this formula.

ravg(value[,reset])

Returns the global arithmetic average of the signal specified as value from acquisition start until the current instant of time; Is reset at measurement start; Can be optionally reset by specifying a reset condition; The update rate is equal to the sample rate of the channel with the highest sample rate that is assigned to this formula.

rrms(value[,reset])

Returns the global RMS of the signal specified as value from acquisition start until the current instant of time; Is reset at measurement start; Can be optionally reset by specifying a reset condition; The update rate is equal to the sample rate of the channel with the highest sample rate that is assigned to this formula.

rsum(value[,reset])

Returns the global sum of the signal specified as value from acquisition start until the current instant of time; Is reset at measurement start; Can be optionally reset by specifying a reset condition; The update rate is equal to the sample rate of the channel with the highest sample rate that is assigned to this formula.

racrms(value[,reset])

Returns the global ACRMS of the signal specified as value from acquisition start until the current instant of time; Is reset at measurement start; Can be optionally reset by specifying a reset condition; The update rate is equal to the sample rate of the channel with the highest sample rate that is assigned to this formula.

For details about the ACRMS, refer to Statistics channel.

rp2p(value[,reset])

Returns the global peak-to-peak level of the signal specified as value from acquisition start until the current instant of time; Is reset at measurement start; Can be optionally reset by specifying a reset condition; The update rate is equal to the sample rate of the channel with the highest sample rate that is assigned to this formula.

A corresponding dmd-file can be found here: https://ccc.dewetron.com/pl/OXYGEN

Array math

It is possible in OXYGEN to use a Formula to extract single harmonics or also frequency bins of the FFT calculation. For a detailed description of how to create an FFT channel see FFT channels. These extracted signals can then be used in a Recorder for example for analysis over time.

To extract single harmonics, create a Formula channel as described in Formula channel, and add the harmonic channel with the Add button (see ⑤ in Fig. 170). This feature is marked with the addition of square brackets and a number at the end of the channel name (see Fig. 188). By default, it will be [0] when adding the channel but can be adjusted to your needs.

For a harmonic channel the [0] represents the fundamental frequency, [1] the first harmonic and so on.

Array math: extraction of single harmonics

Fig. 188 Array math: extraction of single harmonics

This feature can also be used to extract single frequency bins of an FFT Amplitude channel.

Based on the line resolution it has to be determined which frequencies are contained within a certain extracted frequency bin. For an FFT channel the [0] frequency bin to extract represents the steady component. With a line resolution of 1 Hz the [10] frequency bin would represent 10 Hz.

Statistics channel

Pop-up window for creating a statistics channel

Fig. 189 Pop-up window for creating a statistics channel

After clicking on the Add button, the Calculation Setup window will appear (see Fig. 189). For the creation of a Statistics channel, the user must select the desired input channel before clicking on the Add button. The user can select several input channels simultaneously to create several statistic channels with the same settings at once. In the Calculation Setup, the user can define if the Statistics channel shall calculate the AVG, MAX, MIN, RMS or ACRMS value of the input channel. The user may select several statistical values. An individual channel for each value will be created afterwards. After that a time interval (Window Size) for the calculation of the desired value must be defined. Furthermore, the user can define a Group name in which several channels can be summarized in the Data Channels menu. After pressing enter, the channel will appear in the Data Channels menu. The defined channel parameters can be changed afterwards in the Channel Setup (see Fig. 190:).

Statistics Channel Setup Overview

Fig. 190 Statistics Channel Setup Overview

Table 19 Push buttons in the Statistics Channel Setup – Overview

No.

Function

Description

1

Active button

Setting a channel active or inactive; An active channel can be displayed in an instrument, used in a math channel and can be recorded, an inactive channel not.

2

Channel Name

Individual channel name; Can be changed individually.

3

Statistics Mode Setup

Select the statistical value that shall be calculated. Select between AVG, MAX, MIN, RMS and ACRMS.

4

Window Size

Type in the desired window size (will affect the Sample Rate ⑥).

5

Window Size Unit

Select the unit of the window size. Select between seconds (s), minutes (m), hours (h) and days (d) (will affect the Sample Rate ⑥).

6

Sample Rate

Sample rate that is calculated from the Window size in Hz (Window Size can also be changed via Sample Rate changes).

7

Calculation type

Select if the calculation should be carried on continuously or if the calculation should be reset on measurement start.

8

Preview window

Real Time preview of the calculation.

9

Scaling menu

Change the channels’ scaling by entering a Scaling factor or changing the sensitivity (and/or entering an offset) or by a 2-point scaling.

Selectable statistical parameters

i = 1…N

N = Sample Rate of Input Channel * Window Size

  • AVG: Calculates the linear mean value for the selected Window size according to the following formula:

    \text{AVG} = \frac{1}{N}\sum_{i = 1}^{N}{\text{SignalLeve}l_{i}}

  • MAX: Calculates the maximum signal level appearing in the individual time window

    \text{MAX} = \text{MAX}\left\{ \text{SignalLevel}_{i} \right\}

  • MIN: Calculates the minimum signal level appearing in the individual time window

    \text{MIN} = \text{MIN}\left\{ \text{SignalLevel}_{i} \right\}

  • RMS: Calculates the quadratic mean value (RMS) for the selected Window size according to the following formula

    \text{RMS} = \ \sqrt{\frac{1}{N}\sum_{i = 1}^{N}\left( \text{SignalLeve}l_{i} \right)^{2}} = \ \sqrt{\text{AVG}^{2} + \text{ACRM}S^{2}}

  • ACRMS: Calculates the quadratic mean value which is revised from DC components. This value is identical to the standard deviation calculated according to the following formula

    \text{ACRMS} = \ \sqrt{\frac{1}{N}\sum_{i = 1}^{N}\left( \text{SignalLeve}l_{i} - \text{AVG} \right)^{2}}

Note

Difference between the RMS and the ACRMS value: The RMS and the ACRMS value of a signal without DC component is the same. Let’s assume a sine wave with an amplitude of 1 and no DC offset:

Sine wave with amplitude 1, no DC component

Fig. 191 Sine wave with amplitude 1, no DC component

In this case the RMS value is ~0.707 and the ACRMS value is ~0.707 as well.

If the signal has a DC component, the RMS value respects this DC component, but the ACRMS value does not respect the DC component:

Sine wave with amplitude 1, 0.5 DC component

Fig. 192 Sine wave with amplitude 1, 0.5 DC component

For this signal, the RMS value is ~0.866, because the DC component is respected, but the ACRMS value is again ~0.707, because the DC component is not respected.

Filter channel

Pop-up window for creating a (low or high pass) filter channel

Fig. 193 Pop-up window for creating a (low or high pass) filter channel

After clicking on the Add button, the Calculation Setup window will appear (see Fig. 193). For the creation of a Filter channel, the user must select the desired input channel before clicking on the Add button. The user can select several input channels simultaneously to create several filter channels with the same settings at once. After selecting the Filters section, the user can define the following filter characteristics:

  • Filter Type: Low pass, High pass, Bandpass, Band-stop, Differentiator, Integrator

If Low pass or High pass filter is selected (see Fig. 193), the user can select

  • Filter Frequency: from 0 Hz to (\frac{\text{Sample}r\text{ate}}{2} - \frac{\text{Sample}r\text{ate}}{200}) Hz

  • Filter Characteristic: Bessel or Butterworth

  • Filter Order: 2, 4, 6, 8, 10

  • Group name: Define a group in the Channel List to which the filter shall be added

If Bandpass or Bandstop filter is selected (see Fig. 193), the user can select

  • Low Frequency: from 0 Hz to < \text{Upper\ frequency} Hz

  • High Frequency: from \left( \text{Lower\ frequency} + 1 \right)\ Hz to (\frac{\text{Sample}r\text{ate}}{2} - \frac{\text{Sample}r\text{ate}}{200}) Hz

  • Filter Characteristic: Bessel or Butterworth

  • Filter Order: 2, 4, 6, 8, 10

  • Group name: Define a group in the Channel List to which the filter shall be added

If Differentiator is selected, the user can select

Pop-up window for creating a Differentiator channel

Fig. 194 Pop-up window for creating a Differentiator channel

  • Operation: Single or double differentiation

If high frequencies shall be filtered

  • Filter Frequency: from 0 Hz to (\frac{\text{Sample}r\text{ate}}{2} - \frac{\text{Sample}r\text{ate}}{200}) Hz

  • Filter Characteristic: Bessel or Butterworth

  • Filter Order: 2, 4, 6, 8, 10

  • Group name: Define a group in the Channel List to which the filter shall be added

If Integrator is selected, the user can select

Pop-up window for creating an Integrator channel

Fig. 195 Pop-up window for creating an Integrator channel

  • Operation: Single or double integration

If low frequencies shall be filtered

  • Filter Frequency: from 0 Hz to (\frac{\text{Sample}r\text{ate}}{2} - \frac{\text{Sample}r\text{ate}}{200}) Hz

  • Filter Characteristic: Bessel or Butterworth

  • Filter Order: 2, 4, 6, 8, 10

  • Group name: Define a group in the Channel List to which the filter shall be added

Note

Filters can only be applied to synchronous channels, such as analog input channels or counter channels but not to asynchronous channels, such as CAN channels, EPAD cannels, or power group channels.

  • After pressing enter, the channel will appear in the Data Channels menu. The defined channel parameters can be changed afterwards in the Channel Setup (see Fig. 196).

Filter channel setup - overview

Fig. 196 Filter channel setup - overview

Table 20 Push buttons in the Filter Channel Setup – Overview

No.

Function

Description

1

Active button

Setting a channel active or inactive; An active channel can be displayed in an instrument, used in a math channel and can be recorded, an inactive channel not

2

Stored button

Select whether channel data shall be stored or not when measurement is running

3

Color

Color scheme of the channel can be changed here

4

Channel Name

Individual channel name; Can be changed individually

5

Filter Mode Setup

Select the filter type: Lowpass, High pass, Differentiator, Integrator

6

Operation Setup

Select the Operation type Single or Double Integration/ Differentiation (only applicable for Differentiators and Integrators)

7

  • Integrator: Select if low frequencies and DC components shall be filtered.

  • Differentiator: Select if high frequencies shall be filtered

  • Lowpass/Highpass: not applicable.

8

Frequency Selection

Specify the cut-off frequency from 0 to Hz

9

Filter Characteristic Selection

Select between Bessel and Butterworth filter characteristic

10

Filter Order selection

Select a 2nd, 4th, 6th, 8th or 10th filter order

11

Preview window

Real Time preview of the calculation

12

Scaling menu

Change the channels’ scaling by entering a Scaling factor or changing the sensitivity (and/or entering an offset) or by a 2-point scaling

FFT channels

Pop-up window for creating an FFT channel

Fig. 197 Pop-up window for creating an FFT channel

For creating a FFT channel, the user must select the channel and then click on the Add button in the lower left corner (marked red in Fig. 168) and select FFT in the appearing window (see Fig. 193). The user can select several input channels simultaneously to create several FFT channels with the same settings at once.

Note

FFT math can only be applied to synchronous channels, such as analog input channels or counter channels but not to asynchronous channels, CAN channels, EPAD cannels, or power group channels.

Note

The difference between the FFT calculation using this math module or the Instrument Spectrum Analyzer is that the calculation using the math module is deterministic and the calculation using the Spectrum Analyzer is stochastic, i.e. the deterministic calculation can always be reproduced, because the exact instant of time each FFT spectrum is calculated is contained. This is not the case for the stochastic calculation.

In addition, as the FFT calculation using the math module results in own FFT channels, the data can be exported to third party formats using the Export menu in the PLAY mode (for details, refer to Export Settings). This is not the case for the calculation using the Spectrum Analyzer.

Three channels may be created for each FFT calculation:

  • The channel containing the complex spectrum Yk (called Channel_Name_Cpx). This channel cannot be visualized with an OXYGEN Instrument but is only useful for exporting it and using it for post-processing in a 3rd party software.

  • The channel containing the amplitude spectrum Ak (called Channel_Name_Amp) which is calculated according to the following formula:

    A_{k} = \frac{1}{N}\sqrt{\text{Re}\left\{ Y_{k} \right\}^{2} + \text{Im}\left\{ Y_{k} \right\}^{2}}\ ;\ \ \ \ \ \ k = 0\ \ \ \ \ \lbrack\text{Signal\ unit}\rbrack

    A_{k} = \frac{2}{N}\sqrt{\text{Re}\left\{ Y_{k} \right\}^{2} + \text{Im}\left\{ Y_{k} \right\}^{2}}\ ;\ \ \ \ \ \ k = 1\ldots N\ \ \ \ \ \lbrack\text{Signal\ unit}\rbrack

  • This channel can be visualized within OXYGEN using the Spectrum Analyzer (see Spectrum analyzer) if the actual spectrum shall be plotted or it may also be assigned to the Spectrogram Instrument (see Spectrogram) if the time dependent spectral trend shall be displayed.

  • The channel containing the phase information φk (called Channel_Name_Phi) which is calculated according to the following formula:

    \varphi_{k} = \arctan\frac{Im\{ Y_{K}\}}{Re\{ Y_{K}\}};\ \ \ \ \ \ k = 0\ldots N\ \ \ \ \ \lbrack\text{Signal\ unit}\rbrack

  • This channel can be visualized within OXYGEN using the Spectrum Analyzer (see Spectrum analyzer) if the actual spectrum shall be plotted or it may also be assigned to the Spectrogram Instrument (see Spectrogram) if the time dependent spectral trend shall be displayed.

  • This channel is not calculated automatically but must be selected manually in the Channel Setup of the complex spectrum Channel Channel_Name_Cpx after creating the FFT channel (see ⑭ in Fig. 199).

After selecting the FFT section, the user can define the following FFT characteristics:

  • Data size: Select the number of samples to be transformed simultaneously in the frequency domain here. The data size may vary between 42 to 1048576 (220) samples. For calculation details, refer to Instrument Properties for Time Domain Channels.

  • Overlap: Select an overlapping factor from 0 to 99.97559 % here. For calculation details, refer to Calculation of a Periodogram.

  • Window Type: Select an appropriate Window function here. The following windows are available: Hanning, Hamming, Rectangular, Blackman, Blackman-Harris, Flat Top or Bartlett. For calculation details, refer to Window type.

  • Amplitude Spectrum: Select the type of amplitude spectrum the Amplitude channel shall contain. The following amplitude spectra are available: Amplitude, Amplitude_RMS, Amplitude², PSD, Decibel (Ref:1), Decibel_RMS (Ref:1) or Decibel_Max_Peak (Ref: Max). For calculation details, refer to Section Spectrum.

  • If None is selected, no amplitude spectrum channel Channel_Name_Amp but only the complex spectrum channel is created.

  • Group Name: Define a group in the Channel List to which the channel shall be added

  • After pressing the Add button, the FFT for the selected input channel(s) will be calculated and the Output channels will be visible within the FFT Channels topology in the Channel List (see Fig. 198).

    FFT channels within the channel list

    Fig. 198 FFT channels within the channel list

Channel Setup of the Complex spectrum channel

After creating the FFT channel, the following options can be added afterwards within the Channels Setup of the complex Spectrum channel Channel_Name_Cpx:

Complex FFT channel setup - overview

Fig. 199 Complex FFT channel setup - overview

Table 21 Complex FFT Channel Setup – Overview

No.

Function

Description

1

Active button

Setting a channel active or inactive; An active channel can be displayed in an instrument, used in a math channel and can be recorded, an inactive channel not

2

Stored button

Select whether channel data shall be stored or not when a measurement is running

3

Color

Color scheme of the channel can be changed here

4

Channel Name

Individual channel name; Can be changed individually

5

Input channel of the FFT calculation is displayed here.

6

Sample Rate of the input channel is displayed here.

7

Data size selection

Select the number of samples to be transformed simultaneously in the frequency domain here. The data size may between 42 to 1048576 (220) samples. For calculation details, refer to Instrument Properties for Time Domain Channels.

8

Line resolution selection

Enter the data size by entering the desired line resolution here. For calculation details, refer to Instrument Properties for Time Domain Channels .

9

Improve Line Resolution selection

Enable Zero-Padding here. For calculation details, refer to Improve Line Resolution (Enable zero-padding).

10

Window Type selection

Select an appropriate Window function here. The following windows are available: Hanning, Hamming, Rectangular, Blackman, Blackman-Harris, Flat Top or Bartlett. For calculation details, refer to Window type.

11

Normalization Type selection

Select between Amplitude True, Power True or No normalization. For calculation details, refer to Normalization of FFT Spectra.

12

Overlap selection

Select an overlapping factor from 0 to 99.97559% here. For calculation details, refer to Normalization of FFT Spectra.

13

Enable Amplitude channel selection

Enable or disable the calculation of the amplitude channel here; Enabled per default

14

Enable Phase channel selection

Enable or disable the calculation of the phase channel here; Disabled per default

Channel Setup of the Amplitude spectrum channel

After creating the FFT channel the following options can be added afterwards within the Channels Setup of the Amplitude Spectrum channel Channel_Name_Amp:

Amplitude FFT channel setup - overview

Fig. 200 Amplitude FFT channel setup - overview

Table 22 Amplitude FFT Channel Setup - Overview

No.

Function

Description

1

Active button

Setting a channel active or inactive; An active channel can be displayed in an instrument, used in a math channel and can be recorded, an inactive channel not

2

Stored button

Select whether channel data shall be stored or not when a measurement is running

3

Color

Color scheme of the channel can be changed here

4

Channel Name

Individual channel name; Can be changed individually

5

Input channel of the FFT calculation is displayed here.

6

Sample Rate of the input channel is displayed here.

7

Spectrum Type selection

Change the type of the amplitude spectrum here. For calculation details and spectra to be selected, refer to Section Spectrum.

8

Value selection

If Decibel or Decibel RMS spectrum type is selected, the reference value can be entered here

9

Averaging selection

Not implemented yet

10

Preview window

Real Time preview of the calculation

Channel Setup of the Phase spectrum channel

After creating the FFT channel, the following options can be added afterwards within the Channels Setup of the Phase Spectrum channel Channel_Name_Phi:

Phase FFT channel setup - overview

Fig. 201 Phase FFT channel setup - overview

Table 23 Phase FFT Channel Setup - Overview

No.

Function

Description

1

Active button

Setting a channel active or inactive; An active channel can be displayed in an instrument, used in a math channel and can be recorded, an inactive channel not

2

Stored button

Select whether channel data shall be stored or not when a measurement is running

3

Color

Color scheme of the channel can be changed here

4

Channel Name

Individual channel name; Can be changed individually

5

Input channel of the FFT calculation is displayed here.

6

Sample Rate of the input channel is displayed here.

7

Spectrum Type selection

Change the type of the phase spectrum here. For calculation details and spectra to be selected, refer to Section Spectrum.

8

Preview window

Real Time preview of the calculation

Frequency measurement

Pop-up window for creating a frequency measurement channel

Fig. 202 Pop-up window for creating a frequency measurement channel

With this module it is possible to calculate the frequency of a periodical signal. The calculation is based on a block-wise calculation. To create one or several Frequency Measurement Channels click on the + button in the lower left corner of the channel list menu. A pop-up window will appear (see Fig. 202) where Frequency Measurement must be selected. The user can select several input channels simultaneously to create several frequency calculations before clicking on the + button or choose the channels after creating the Frequency Measurement channel.

After clicking on the Add button a new section in the channel list appears named Frequency Measurement Channels.

When clicking on the little gear button the settings of the frequency channel will open.

Frequency Measurement Channels in Channel List

Fig. 203 Frequency Measurement Channels in Channel List

Frequency Measurement Channel settings

Fig. 204 Frequency Measurement Channel settings

The following settings are available:

  • Input channels: the input channels for the calculation can be selected when clicking on the button; a small pop-up window will appear where the desired channels can be changed or selected.

  • Window overlap: the window overlap can be entered here from 0 to 90 %.

  • Window duration: the window duration can be entered in this field, or a value can be chosen from the dropdown list; the minimum window duration is 10 ms up to 1 s.

  • Min. frequency: the minimum frequency which should be calculated must be entered here; the minimum frequency is 0 Hz.

  • Max. frequency: the maximum frequency which should be calculated must be entered here; the maximum frequency is 5000 Hz.

Advanced math

Power Groups

This is an optional feature and requires a license.

Pop-up window for creating a Power Group

Fig. 205 Pop-up window for creating a Power Group

A Power Group can be created by pressing either the Add button or the Calculator button in the lower left corner of the Data Channels menu (both buttons marked red in Fig. 205).

For details about the OXYGEN Power module refer to the Power Technical Reference Rx.x Manual which is available on the DEWETRON CCC-portal (https://ccc.dewetron.com/).

OXYGEN Order Analysis plugin

This is an optional feature and requires a license.

Pop-up window generating an order analysis

Fig. 206 Pop-up window generating an order analysis

An order analysis can be created and configured by pressing the Add button in the lower left corner of the Data Channels menu (marked red in Fig. 206).

For details about the Order Analysis plugin refer to the DEWETRON_Oxygen_Order_Analysis_vx.x Manual which is available on the DEWETRON CCC-portal (https://ccc.dewetron.com/).

Swept Sine Analysis

This is an optional feature and requires a license.

The Swept Sine Analysis can be used to determine the transfer function and the bode diagram of a DUT that is stimulated by a shaker which is driven by a wave-generator replaying a sine sweep. An exemplary testbed could look like the following (see Fig. 207):

Exemplary testbed to use the Swept Sine Analysis plugin

Fig. 207 Exemplary testbed to use the Swept Sine Analysis plugin

A DUT is standing on a shaker. The shaker is driven by a Signal Generator which replays a sine sweep. One accelerometer is applied directly on the shaker and provides the reference (source) signal that is used to stimulate the DUT. One or several additional accelerometers are applied directly on the DUT that measure the acceleration on the DUT surface on different positions (sink).

These signals can be applied to the Swept Sine Analysis plugin to determine the transfer function and the phase shift from source to sink.

Setting up a Swept Sine Analysis

To set up the Swept Sine Analysis plugin, perform the following steps:

  1. At first, mark the checkbox of the channel which provides the reference signal for the Swept Sine Analysis (see ① in Fig. 208)

  2. Next, mark the channel that provides the signal measured on the signal sink (see ② in Fig. 208). Several sink signals could be applied to one Swept Sine Analysis group.

  3. Click on the PLUS (see ③ in Fig. 208) sign to open the math setup and select Swept Sine Analysis. Edit the channel group name if desired and click on the OK button afterwards.

Steps to configure a Swept Sine Analysis

Fig. 208 Swept Sine Analysis

Setup overview
Swept Sine Analysis setup – overview

Fig. 209 Swept Sine Analysis setup – overview

Table 24 Swept Sine Analysis setup – overview

No.

Function

Description

1

Reference channel selection

The channel that provides the reference signal can be edited here; This channel is used to determine the fundamental frequency which is available in the channel F_fund (see Swept Sine analysis output channels)

2

Detection Threshold selection

Amplitude threshold for determining the fundamental frequency; If the amplitude of the reference channel is below the specified threshold (percentage of the channel input range), the fundamental frequency will not be determined; I.e. Channel Input Range = 100 V and Detection Threshold = 1%; The signal amplitude must be 1V or higher to determine the fundamental frequency

3

Calculation mode selection

RMS or Zero-Peak selectable; The output channels (see Swept Sine analysis output channels) may contain either the RMS or Zero-to-Peak level as result

4

Start frequency selection

Enter the lower frequency limit for the Swept Sine Analysis

5

Stop frequency selection

Enter the upper frequency limit for the Swept Sine Analysis

6

Step size selection

Enter the frequency resolution of the Swept Sine Analysis

7

Periods selection

Number of signal periods of the reference signal that shall be used for updating one value

8

Input channels selection

Select the input channels that contain the sink signals (sensors that applied on the DUT); One or several sensors can be selected

9

Enable immediate value channels switch

The channels that contain the time domain signals (see Swept Sine analysis output channels) are enabled with this switch; Per default disabled

10

Enable Bode diagram switch

The channels that contain the frequency domain signals (see Swept Sine analysis output channels) are enabled with this switch; Per default enabled

11

Max update rate selection

Select the calculation update rate (from 1 to 10s)

Swept Sine analysis output channels
  • F_fund: Contains the fundamental frequency of the Swept Sine Analysis; Calculation based on the signal provided by the reference (source) channel

  • ChannelName_iRMS or ChannelName_iPeak: Time domain channel; Contains the amplitude (RMS or Zero-to-Peak level depending on the selection in ③ in Fig. 209) of the signal at the actual frequency; The amplitude is only referring to the fundamental frequency signal components; Can be assigned to a Recorder (see Recorder), Digital Meter (see Digital meter) or similar.

  • ChannelName_iPhi: Time domain channel; Contains the phase shift of the signal at the actual frequency; Can be assigned to a Recorder (see Recorder), Digital Meter (see Digital meter) or similar.

  • ChannelName_iUFRMS or ChannelName_iUFPeak: Time domain channel; Contains the amplitude (RMS or Zero-to-Peak level depending on the selection in ③ in Fig. 209) of the signal at the actual frequency; The amplitude is referring to the entire signal components; Can be assigned to a Recorder (see Recorder), Digital Meter (see Digital meter) or similar

  • ChannelName_RMS or ChannelName_Peak: Frequency domain channel; Contains the transfer function (RMS or Zero-to-Peak level depending on the selection in ③ in Fig. 209); The amplitude is referring to the fundamental frequency signal components; Can be assigned to a Spectrum Analyzer (see Spectrum analyzer) instrument for displaying the data.

  • ChannelName_Phi: Frequency domain channel; Contains the phase diagram; Can be assigned to a Spectrum Analyzer (see Spectrum analyzer) instrument for displaying the data.

  • ChannelName_UFRMS or ChannelName_UFPeak: Frequency domain channel; Contains the transfer function (RMS or Zero-to-Peak level depending on the selection in ③ in Fig. 209); The amplitude is referring to the entire signal components; Can be assigned to a Spectrum Analyzer (see Spectrum analyzer) instrument for displaying the data.

Calculation remarks
  • The maximum frequency span is from 1 to 20000 Hz. To achieve a suitable accuracy, it is recommended to set the sample rate of the input channels to at least 20 times the maximum frequency, i.e. to 20 kHz in case of 1 kHz maximum frequency span.

  • The highest resolution of the frequency domain channels is 1 Hz. Data of non-integer frequency bins is rounded to the next integer frequency bin.

  • If the sweep does not exactly hit exactly one frequency bin which is contained in the data array, data for the certain frequency bin is filled up by linear interpolation of the two narrowed frequency bins

  • The channels containing frequency domain data contain only one single value data array at the end of the measurement. In case of multi-file recording (see Multi-file recording), this data array will only be included in the last data file, the other files will not contain this data.

  • If the sweep is passing the same frequency several times, there will not be several values for the same frequency stored, but the maximum value only is stored to the data file.

  • If the screen is frozen (see ⑦ in Fig. 10) and the orange cursor is moved either in the Overview Bar or in a Recorder, the data of the single value array will change approximately every second as the array is continuously filled with data. In the end, there will only be the final value.

  • As the channels containing frequency domain data contain only one single value data array at the end of the measurement, there will not be reduced Statistics data available (see Triggered Events).

Rosette (strain gauge) channels

Pop-up window for creating a Rosette calculation

Fig. 210 Pop-up window for creating a Rosette calculation

For creating a Rosette channel, the user must click on the Add button in the lower left corner (marked red in Fig. 168) and a window will appear (see Fig. 210). To create a Rosette channel, select Rosette. After clicking on the OK button, a Rosette main channel (Rosette_1 in Fig. 211) with its Sub channels (Max Principal strain to VonMises Stress in Fig. 211) is added to the channel List. A click on the gear button of the main rosette channel will open the Rosette settings to perform changes afterwards (see Fig. 211).

Rosette channel setup – overview

Fig. 211 Rosette channel setup – overview

Table 25 Rosette channel setup – overview

No.

Function

Description

1

Channel List

Channel List including the output channels of the Rosette calculation.

2

Channel setup button

Opens the channel setup of the individual channel.

3

Color

Color scheme of the channel can be changed here.

4

Channel Name

Individual channel name; Can be changed individually.

5

Rosette Type selection

Select the rosette calculation type here: 45°, 60°, 90° (T).

6

Poisson ratio selection

Enter the poisson ration here.

7

Young modulus selection

Enter the Young modulus of the used material here.

8

Stress unit selection

Select the unit of the Young modulus here: [MPa], [GPa] or [kgf/mm²].

9

Strain unit selection

Select the strain unit here: [µm/m] or [microstrain].

10

Epsilon A channel assignment

Assign the input channel for Epsilon A here.

11

Reference Angle Selection

Select Epsilon A as Reference Angle here; If selected, the background will highlight grey-blue.

12

Epsilon B channel assignment

Assign the input channel for Epsilon B here.

13

Reference Angle Selection

Select Epsilon B as Reference Angle here; If selected, the background will highlight grey-blue.

14

Epsilon C channel assignment

Assign the input channel for Epsilon C here.

15

Reference Angle Selection

Select Epsilon C as Reference Angle here; If selected, the background will highlight grey-blue.

16

Reference Angle hint

Highlights the selected reference angle in the rosette schematics.

17

Output channel activation

Activate or deactivate the single channels that shall be calculated and output by the calculation.

Required input channels

The Plugin requires three strain gauge input channels (Epsilon A, B, C), the angular rosette alignment (45°, 60°, 90° (T)) and the angle reference (A, B, C). Available input channels for Epsilon A, B, C are analog input channels. The 90° or Tee type rosette requires only 2 input channels (Epsilon A, B).

The advantage of using three-channel rosettes is to minimize the effect of error due to misalignment to the elements from the physical axis. Furthermore, the bigger the angle between the gauges, the better the result concerning noise influence.

Note

Channels that are assigned to the Rosette plugin require the engineering unit µm/m or um/m. Other engineering units are not accepted and will lead to the error message Unit of input channels not µm/m or um/m in the Channel Setup of the main rosette channel (see Fig. 212).

Error message in case of wrong engineering unit

Fig. 212 Error message in case of wrong engineering unit

The channel to be used for the rosette calculation can be selected before clicking on the Calculator button. If channels 1/1, 1/2 and 1/3 are selected one after the other and a three channel is selected, the channels will be assigned automatically in the following manner after clicking the OK button in the Rosette Calculation Setup: 1/1 to Epsilon A, 1/2 to Epsilon B and 1/3 to Epsilon C.

If channels 1/3, 1/1 and 1/2 are selected one after the other and a three channel is selected, the channels will be assigned automatically in the following manner after clicking the OK button in the Rosette Calculation Setup: 1/3 to Epsilon A, 1/1 to Epsilon B and 1/2 to Epsilon C

If six channels 1/1, 1/2, 1/3, 1/4, 1/5 and 1/6 are selected one after the other, two three-channel rosettes or three two-channel rosettes can be created with one click on the Calculator button. The input channels will be assigned in the following manner (example for two three-channel rosettes):

  • Rosette 1: 1/1 to Epsilon A, 1/2 to Epsilon B and 1/3 to Epsilon C

  • Rosette 2: 1/4 to Epsilon A, 1/5 to Epsilon B and 1/6 to Epsilon C

If four channels1/1, 1/2, 1/3, 1/4 are selected one after the other and two three-channel rosettes shall be created, the input channels will be assigned in the following manner:

  • Rosette 1: 1/1 to Epsilon A, 1/2 to Epsilon B and 1/3 to Epsilon C

  • Rosette 2: 1/4 to Epsilon A, Epsilon B and Epsilon C will remain unassigned

The channel assignment can be edited after creating the Rosette calculation in the Channel setup of the main channel (see ⑯ in Fig. 211) by dragging and dropping the desired channel from the Channel List on the left-hand side to the individual input channel of the rosette calculation (see Fig. 213).

Channel assignment in the rosette channel setup

Fig. 213 Channel assignment in the rosette channel setup

If the assignment of a rosette input channel is missing, the error message Input channels not ready will be displayed at the bottom of the Channel Setup (see Fig. 214).

Error message in case of missing channel assignment

Fig. 214 Error message in case of missing channel assignment

The sample rate of the channels assigned to one rosette calculation must all be same . If they differ, the error message Sample rates of input channels differ will be displayed at the bottom of the Channel Setup (see Fig. 215).

Error message in case of different channel sample rates

Fig. 215 Error message in case of different channel sample rates

The sub channels (see ⑰ in Fig. 211) resulting from the rosette calculation have a Channel Setup that can be accessed via the Gear Button in the Channel List as well. But only the Channel scaling can be edited there.

Resulting output channels

The plugin uses the so-called Mohr’s circle (see Mohr’s circle) for the calculations. For details, refer to the relevant literature.

Mohr's circle

Fig. 216 Mohr’s circle

The calculated values are represented in channels, which are shown below.

  • Max Principle Strain → Max. Strain in angle direction [µm/m] or [microstrain]

  • Min Principle Strain → Min. Strain in angle +90° direction [µm/m] or [microstrain]

  • Angle → Angle of max. strain [°]

  • Average Strain → Center of Mohr’s circle [µm/m] or [microstrain]

  • Max Shear Strain → Radius of Mohr’s circle [µm/m] or [microstrain]

  • Max Principle Stress → Max. stress in angle direction [MPa]

  • Min Principle Stress → Min. stress in angle +90° direction [MPa]

  • Max Shear Stress → Max. shear stress in angle direction [MPa]

  • Von Mises Stress → Virtual uniaxial stress [MPa]

Usage of the plugin

The Rosette Math plugin is used to determine the angle and max/min amplitude of strain and stress on a surface. This is used when it is not known which direction of strain/stress has to be expected.

Rosette strain gauges are available combined in one foil (stacked construction), alternatively it is possible to use three separate strain gauges (planar construction).

Fig. 217 shows sketches of different rosette types: left: 90° (T), middle: 45°, right: 120° rosette.

Sketch of different rosette types

Fig. 217 Sketch of different rosette types

Physical basics

This chapter includes some important term explanations.

  • Strain : Is the mechanical deformation measured as a relation between length change relative to the initial length:

    \varepsilon = \ \frac{\text{dl}}{l}\ \left\lbrack \frac{µm}{m} \right\rbrack

  • The strain is usually presented in µm/m, so the ratio of elongation is micrometers comparing to the length of a specimen in meters. So, what does that mean if we measure a value of 2000? First of all, we can also express this in percent. Strain in µm/m divided by a factor of 10000 results in elongation in percent. In the case of 2000, the elongation will be 0.2 %.

  • Stress : Is defined as the average force per unit area, also taking in account the material.

    \sigma = \ \frac{F}{A}\ \left\lbrack \frac{N}{mm^{2}} \right\rbrack

  • Young’s modulus: The formulas shown above only work in the linear part of the Strain-Stress-Curve, which is shown in Fig. 218. In this area a constant factor between stress and strain exists.

    Strain-Stress-Curve

    Fig. 218 Strain-Stress-Curve

    E = \ \frac{\sigma}{\varepsilon}\ \left\lbrack M\frac{N}{mm^{2}} = GPa \right\rbrack

Where Е is the Young’s modulus or Elastic modulus. This constant is depending on the used material (e.g. steel = 210 kN/mm²). The measured value from the strain gauge is therefore the strain and you get the stress by calculating .

Implemented formulas

The Rosette calculations depend on the selected rosette type and angle reference.

Constants

\varepsilon_{P}\ldots Max.\ Hauptdehnung

\varepsilon_{Q}\ldots Min.\ Hauptdehnung

\theta\ldots Winkel\ in\ Richtung\ der\ max.\ Hauptdehnung

Angle Reference

  • A:\ \theta_{P,Q} = (\ldots)\

  • B:\ \theta_{P,Q} = (\ldots) - 45{^\circ}\ \text{or}\ 60{^\circ}

  • C:\ \theta_{P,Q} = (\ldots) - 90{^\circ}\ \text{or}\ 120{^\circ}\ \text{or}\ 240{^\circ}

Calculation of 45° and 90° Rosette

Avg Strain

MaxShearStrain

\varepsilon_{P} = \varepsilon_{1}

\varepsilon_{Q} = \varepsilon_{2}

\varepsilon_{P,Q} = \frac{\varepsilon_{1} + \varepsilon_{3}}{2} \pm \frac{1}{\sqrt{2}}\sqrt{\left( \varepsilon_{1} - \varepsilon_{2} \right)^{2} + \left( \varepsilon_{2} - \varepsilon_{3} \right)^{2}}

\theta_{P,Q} = \ \frac{1}{2}\ \tan^{- 1}{(\frac{2\varepsilon_{2} - \varepsilon_{1} - \varepsilon_{3}}{\varepsilon_{1} - \varepsilon_{3}})}

Calculation of 60° and 120° Rosette

\varepsilon_{P,Q} = \frac{\varepsilon_{1} + \varepsilon_{2} + \varepsilon_{3}}{3} \pm \frac{\sqrt{2}}{3}\sqrt{\left( \varepsilon_{1} - \varepsilon_{2} \right)^{2} + \left( \varepsilon_{2} - \varepsilon_{3} \right)^{2} + \left( \varepsilon_{3} - \varepsilon_{1} \right)^{2}}

\theta_{P,Q} = \ \frac{1}{2}\ \tan^{- 1}{(\frac{\sqrt{3}{(\varepsilon}_{2} - \varepsilon_{3})}{{2\varepsilon}_{1} - \varepsilon_{2} - \varepsilon_{3}})}

Calculations valid for all Rosette types
  • Max/Min Principle Stress

    \sigma_{P} = \ \frac{E}{1 - \gamma^{2}}(\varepsilon_{P} + \gamma\varepsilon_{Q})\ \left\lbrack \frac{N}{m^{2}} \right\rbrack

    \sigma_{Q} = \ \frac{E}{1 - \gamma^{2}}(\varepsilon_{Q} + \gamma\varepsilon_{P})\ \left\lbrack \frac{N}{m^{2}} \right\rbrack

  • Von Mises Stress

    \sigma_{\text{vM}} = \ \sqrt{\frac{\left( \sigma_{P} - \sigma_{Q} \right)^{2} + \sigma_{P}^{2} + \sigma_{Q}^{2}}{2}}\ \left\lbrack \frac{N}{m^{2}} \right\rbrack

  • Max Shear Stress

    \sigma_{\text{SP}} = \frac{\sigma_{P} - \sigma_{Q}}{2}\ \left\lbrack \frac{N}{m^{2}} \right\rbrack

  • Addition to Angle Calculation

The following table shows how to determine the principal axis angle φ0 taking the sign of the numerator and the enumerator into account

Quadrant

Z

N

Angle φ0

I

+

+

0° ≤ φ0 ≤ +45°

II

+

-

+45° ≤ φ0 ≤ +90°

III

-

-

-45° ≤ φ0 ≤ -90°

IV

-

+

0° ≥ φ0 ≥ -45°

Psophometer

In telecommunications, a psophometer is an instrument that measures the perceptible noise of a telephone circuit.

The core of the meter is based on a true RMS voltmeter, which measures the level of the noise signal. This was used for the first psophometers, in the 1930s. As the human-perceived level of noise is more important for telephony than their raw voltage, a modern psophometer incorporates a weighting network to represent this perception. The characteristics of the weighting network depend on the type of circuit under investigation, such as whether the circuit is used to normal speech standards (300 Hz – 3.3 kHz), or for high-fidelity broadcast-quality sound (50 Hz – 15 kHz).

Setup

The Psophometer plugin is installed with every OXYGEN installation, starting from R3.5.1

A dedicated plugin license is required for the calculation option to be visible.

Usage
  1. Select one or multiple channels as inputs for the Psophometer calculation.

    Note

    Input channels must have a sampling rate of 20 kHz or higher.

    Channel list with multiple selected channels

    Fig. 219 Channel list with multiple selected channels

  2. Then open the “Add Channel” dialog by pressing the plus button.

  3. Select Psophometer. The dialog now shows the Psophometer frequency weighting settings (see Weighting) which can be made.

  4. The newly created Psophometer calculation group can be named individually.

    Add Channel dialog showing Psophometer options

    Fig. 220 Add Channel dialog showing Psophometer options

  5. Finally, press Add to create the new calculation group.

    Channel list showing new Psophometer calculation group

    Fig. 221 Channel list showing new Psophometer calculation group

The channel details view is used to modify each channel’s settings individually and for detailed preview.

Channel details setup of calculation channel

Fig. 222 Channel details setup of calculation channel

Psophometer calculations are then available as math channels.

Sidebar channel list showing the calculated Psophometer channels

Fig. 223 Sidebar channel list showing the calculated Psophometer channels

Calculation

The calculation is based on FFT.

Depending on the input sampling rate, the FFT block size is chosen to be 2^N samples while the time window stays between 75 and 125 ms, to ensure passing the detector circuitry tests (see ITU-T Recommendation O.41 (10/94)).

Sampling rate

FFT block size

20 kHz

2048

50 kHz

4096

100 kHz

8192

200 kHz

16384

Weighting

Different weighting options are available:

ITU-T O.41

Telephone circuit Psophometer weighting coefficients and limits

Fig. 224 Telephone circuit Psophometer weighting coefficients and limits

C-message

C-message weighting coefficients and accuracy limits

Fig. 225 C-message weighting coefficients and accuracy limits

Flat

Characteristics of the optional flat filter with an equivalent noise bandwidth of 3.1 kHz (bandwidth of a telephone channel)

Fig. 226 Characteristics of the optional flat filter with an equivalent noise bandwidth of 3.1 kHz (bandwidth of a telephone channel)

Unweighted

Frequency response characteristics for unweighted measurements

Fig. 227 Frequency response characteristics for unweighted measurements

Comparison between Psophometric and C-message weighting

Comparison between psophometric and C-message weighting

Fig. 228 Comparison between psophometric and C-message weighting

ITU-T Recommendation O.41 (10/94)

https://www.itu.int/rec/T-REC-O.41-199410-I/en

OXYGEN Sound Level plugin

This is an optional feature and requires a license.

Pop-up window generating a sound level plugin

Fig. 229 Pop-up window generating a sound level plugin

A Sound Level can be created and configured by pressing the Add button in the lower left corner of the Data Channels menu (marked red in Fig. 229).

For details about the Sound Level plugin refer to the DEWETRON_Sound_Level_determination_vx.x Manual which is available on the DEWETRON CCC-portal (https://ccc.dewetron.com/).

Matrix Sampler

This is an optional feature and requires a license (OPT-POWER-ADV).

The matrix sampler is a feature, which is included in the advanced Power calculation. This feature displays the relation between two channels and an input channel in form of a color-coded matrix which is displayed in the Intensity Diagram instrument.

Creation of a Matrix Sampler Channel

There are two ways to create a matrix sampler channel:

  1. Select at least one channel which should be used as reference channel (X, Y and input channel Z) in this order (channels can also be changed afterwards). Click on the + button in the lower left corner, select Matrix Sampler in the list and click on the Add button (see Fig. 230).

    Creation of a Matrix Sampler channel from channels in the channel list

    Fig. 230 Creation of a Matrix Sampler channel from channels in the channel list

  2. The other possibility to create a matrix sampler channel in form of an efficiency map is in the Power Group settings. For a detailed explanation on how to create a Power Group see Power Groups or refer to the Power Technical Reference Rx.x Manual which is available on the DEWETRON CCC-portal (https://ccc.dewetron.com/).

    Open the Power Group settings and go to Mechanical in the advanced settings. By simply clicking on the Add efficiency map button (see Fig. 231), a matrix sampler channel will be created with the according channels (speed, torque, and efficiency) to display the respective efficiency map of the Power Group.

    Creation of a Matrix Sampler channel as an efficiency map of an according Power Group

    Fig. 231 Creation of a Matrix Sampler channel as an efficiency map of an according Power Group

    After creating a matrix sampler channel by either one of these ways, a new section appears in the channel list seen in Fig. 232. For each matrix sampler one new channel will be created.

    New section for Matrix Sampler channels in the channel list

    Fig. 232 New section for Matrix Sampler channels in the channel list

Matrix Sampler Channel Settings

Some of the channel settings of the matrix sampler channel in this section will be explained by the example of an efficiency map. However, the settings or channels are not bound to a unit of a channel and can be used with any measured channel. An overview of the channel settings can be seen in Fig. 233. To enter the channel settings click on the gear icon of the channel in the channel list (see Fig. 232).

The following section will explain all the settings, respectively.

Channel settings of a Matrix Sampler channel

Fig. 233 Channel settings of a Matrix Sampler channel

Fig. 234 shows a detailed overview of the available channel settings of a matrix sampler channel.

Detailed view of the setting of a Matrix Sampler channel

Fig. 234 Detailed view of the setting of a Matrix Sampler channel

Table 26 Detailed view of the setting of a Matrix Sampler channel

No.

Function

Description

1

X, Y, Z reference channels selection

The reference channels for X, Y and Z can be selected here. Z acts as the input channel, which will be displayed. Channels can also be assigned via drag’n’drop or by clicking on the channel list button marked in red in Fig. 234

2

Averaging

The time window to calculate the average of input channel Z

3

Trigger Channel

Selection of a trigger channel; this channel is used as a trigger to take a sample for the matrix

4

Trigger Level

Defines the level upon which the trigger is initiated

5

Rearm

Defines the rearm level, upon which the trigger will be reactivated

6

Threshold

Defines the range within the X and Y signal must stay in order to arm the trigger

7

Time

Defines the time of the X and Y signal to stay within the defined threshold range to arm the trigger

8

Delay Trigger

Defines the time delay, after which a sample will be put into the matrix after the trigger is activated

9

Take Sample

Button to manually take a sample to put in the matrix

10

Disarm/Arm Trigger

Trigger settings will be disarmed/armed; if disarmed matrix will not be updated anymore

As explained in the section before, the channels can either be chosen in the right order before creating the matrix sampler channel, but they can also be changed or assigned via drag’n’drop or the channel list button afterwards.

The channels for an efficiency map are assigned properly when creating an efficiency map out of the Power Group settings. For an efficiency map the speed is used as the reference channel for the X-axis, torque for the Y-axis and the mechanical efficiency for the Z-axis as input channel.

For the trigger channel a signal can be used from a testbed environment to define, when a sample should be put into the matrix. In the example shown in Fig. 234 it can be seen, that a sample will be taken whenever the channel Trigger Channel rises above a defined level of 0.5 V. The trigger will be activated again, once the Trigger Channel drops below 0.2 V, which is defined as the rearm level.

Note

For the trigger settings, either a channel can be selected as trigger or the Steady State Detection (X and Y) can be used. If a channel is selected as trigger channel, the Steady State Detection is disabled. To use the Steady State Detection no channel can be selected as trigger channel or must be deleted. The conditions threshold and time for the Steady State Detection have to be fulfilled by the X and the Y channel in order to arm the trigger.

The Disarm/Arm Trigger button is very useful if a specific measurement point needs to be repeated. In order not to overwrite the whole matrix, the trigger can be disarmed. Therefore, the matrix will not be updated for each trigger, and samples are not saved. Whenever the measurement point is reached, a sample can manually be put in the matrix by clicking the Take Sample button.

Fig. 235 shows the exemplary resulting output matrix in the channel settings. For each the Y- and the X-axis the minimum, maximum and step size can be defined in the corresponding channel unit. When entering the step size, the resulting steps are displayed below.

Detailed view of the map setting of a Matrix Sampler channel

Fig. 235 Detailed view of the map setting of a Matrix Sampler channel

To display this efficiency map on the measurement screen simply drag and drop the matrix sampler channel onto the measurement screen. Otherwise use the intensity diagram instrument and select the channel accordingly.

For more information about the instrument refer to Intensity Diagram.

CPB analysis

This is a standard feature and requires no additional license.

The CPB analysis computes a constant percentage bandwidth spectrum according to EN 61260 in Octave, Third octave or Twelfth octave resolution.

Creating a CPB Analysis
Creating a CPB Analysis

Fig. 236 Creating a CPB Analysis

  1. Go to the Channel List and select one or several channels by checking their check boxes and press the + button

  2. Select CPB Analysis, choose the proper calculation options and enable the required output channels (Details can be found in CPB analysis options)

  3. Press Add afterwards to create the calculation. The channels will be added to the Channel List (see ④ in Fig. 237)

  4. The settings can be accessed afterwards by clicking on the Gear button of the channel (see ⑤ in Fig. 237)

An Array Chart instrument can be used for visualizing the CPB spectrum. Further details can be found in Array Chart with Total column included.

Edit the CPB settings after creation

Fig. 237 Edit the CPB settings after creation

CPB analysis options

The following options can be selected for a CPB Analysis (see ② in Fig. 236):

  • Group Name: Set a group name for the actual calculation which appears in the Channel List

  • Octave mode: Select Octave, Third octave or Twelfth octave resolution (grouping according to EN 61260)

  • Minimum Frequency: Set a minimum frequency for computation. If the selected frequency is not the center frequency of a CPB bin, the bin including this frequency will be used as minimum bin

  • Maximum Frequency: Set a maximum frequency for computation. If the selected frequency is not the center frequency of a CPB bin, the bin including this frequency will be used as maximum bin

  • Window type: Select between Hamming, Hanning, Rectangular, Blackman, Blackman-Harris, Flattop, Flattop-Bartlett Window for the spectral analysis

  • Overlap: Select an overlapping factor from 0 … 90 % for the spectral analysis

  • Amplitude Spectrum: Select between Amplitude spectrum or Decibel spectrum with freely definable reference value and corresponding reference level

  • Frequency Weighting: Select between frequency weighting according to DIN-EN 61672: A-, B-, C-, D- or Z- (linear) weighting

  • Output Channels: Activate output channels:

    The actual CPB spectrum (changing in time) is calculated per default. The channel name is CPB (see ④ in Fig. 237).

    If Compute energetic sum over individual bins is enabled, the energetic sum for the spectrum is calculated. The channel name is Energetic Sum (see ④ in Fig. 237).

In case it is an Amplitude spectrum, the calculation is the following:

\text{Energetic}\ \text{Sum} = \ \sqrt{\sum_{i = 1}^{n}x_{i}^{2}}

  • n … Number of CPB bins

  • xi … CPB bin with index i

In case it is a Decibel spectrum, the calculation is the following:

\text{Energetic}\ \text{Sum} = \ 10*log\sqrt{\sum_{i = 1}^{n}{{(10}^{\frac{x_{i}}{10}})²}}

  • n … Number of CPB bins

  • xi … CPB bin with index i

If Compute overall Values is enabled, one CPB spectrum averaged for the whole measurement time and an energetic sum (if enabled) averaged for the whole measurement time will be calculated.

The calculation will be reset at recording start. The channel name will be CPB Overall and Energetic Sum Overall (see ④ in Fig. 237).

If Extract individual frequency bands is enabled, frequency bands can be output as time domain channels. I.e. If 100 Hz is entered, the 100 Hz band will be extracted as time domain channel to analyze the time dependent trend.

It is possible to extract several bands (see Fig. 238).

If the entered frequency is not the center frequency of a CPB bin, the bin including this frequency will be extracted.

CPB Analysis with extracted 100 Hz and 250 Hz bin

Fig. 238 CPB Analysis with extracted 100 Hz and 250 Hz bin

Data sources

OXYGEN Ethernet Receiver

This is an optional feature and requires a license.

Pop-up window for acquiring an Ethernet Receiver Data stream

Fig. 239 Pop-up window for acquiring an Ethernet Receiver Data stream

An Ethernet Receiver data stream can be acquired and configured by pressing the Add button in the lower left corner of the Data Channels menu (marked red in Fig. 239).

For details about the Ethernet Receiver plugin refer to the OXYGEN Ethernet Receiver XML Configuration Vx.x Manual which is available on the DEWETRON CCC-portal (https://ccc.dewetron.com/).

Modbus Receiver

For details about theModbus receiver plugin refer to the OXYGEN Modbus TCP manual which is available on the DEWETRON CCC portal.

Protocols

MIL-STD-1553 Decoder

For details about the MIL-STD-1553 Decoder plugin refer to the MIL-STD-1553 Decoder manual which is available on the DEWETRON CCC portal.

ARINC Decoder

For details about the ARINC Decoder plugin refer to the ARINC Decoder manual which is available on the DEWETRON CCC portal.

Offline math

The topology Offline Math deems calculations that shall be performedafter the measurement is finished within a data file. The following Offline Math features are supported. The features will be extended within the proximate OXYGEN releases.

  • Channels can only be edited within one open session. This denotes that channels can be created and edited as long as a data file is opened. After re-opening a data file, the previously created channels cannot be edited any more.

  • Channels can be added in the same manner as explained in Mathematical channels by clicking on the + button (see Fig. 168) at the lower left side of the Channel List.

  • Channels created within one open session can be deleted by clicking on the Delete Math Channel button (see Table 7). After re-opening a data file, the previously created channels cannot be deleted any more.

  • Formulas, Filters, Statistics and FFT channels can be created and edited within one session. The Psophometer plugin, the Swept Sine Analysis plugin, the Rosette determination, the sound level option and the CPB analysis can be used offline as well.

  • Power Groups can be created offline since OXYGEN R5.4.

  • Offline Math is not applicable for the scaling of an analog input channel.

  • Channel dependencies are respected during Offline Math calculations. This denotes that it is possible to create a Filter channel and a Statistics Channel that is applied on this certain Filter channel within one session. If the Filter channel is edited again, the Statistics channel will automatically be recalculated, too.

  • Channels that have been created offline can be recognized on the Green Record button in the Channel List (see Fig. 240):

    Recognition of offline created channels

    Fig. 240 Recognition of offline created channels

  • Created channels and any changes can be stored to the data file by pressing the Store data button (see Fig. 241 or ⑬ in Fig. 10):

    *Store data* button

    Fig. 241 Store data button

  • Created channels and any changes can be exported to a setup file by pressing the Save setup file button (see Fig. 242 or ⑮ in Fig. 10):

    *Save setup file* button

    Fig. 242 Save setup file button

  • A Progress indicator will inform about the actual calculation progress (see Fig. 243) and contains information about the number of calculated channels, the calculation progress in percent and the remaining calculation time:

    Progress indicator for Offline Math calculations

    Fig. 243 Progress indicator for Offline Math calculations

  • A data file recorded with OXYGEN 2.x can be opened with OXYGEN 3.x to apply Offline Math. After storing changes to the data file, it cannot be opened with OXYGEN 2.x again but only with OXYGEN 3.x.

  • Be aware that an Offline Statistics channel will differ from an Online Statistics channel, i.e. at the beginning of the file or in case of Event based waveform recording (see Triggered Events). In the example displayed in Fig. 244, the green channel is an online calculated Statistics channel applied on the yellow analog channel and the red channel is an offline calculated Statistics channel applied on the yellow analog channel with identical channel settings. The deviation of the green and the red channel is due to the availability of the full analog data during online calculation. During the offline calculation, only the event based recorded analog data is available.

    Deviation of Offline and Online Statistics channels in case of Event based Waveform recording

    Fig. 244 Deviation of Offline and Online Statistics channels in case of Event based Waveform recording

  • Be aware that an Offline Filter channel will differ from an Online Filter channel, i.e. at the beginning of the file or in case of Event based waveform recording (see Triggered Events). In the example displayed in Fig. 245, the green channel is an online calculated Integrator applied on the yellow analog channel and the red channel is an offline calculated integrator applied on the yellow analog channel with identical channel settings. The deviation of the green and the red channel happens, because the offline calculated integrator will oscillate at the beginning of each new event, but the online calculated integrator not, because the analog data is always available during online calculation.

    Deviation of Offline and Online Statistics channels in case of Event based Waveform recording

    Fig. 245 Deviation of Offline and Online Filter channels in case of Event based Waveform recording

Loading external video data

Pop-up window for loading an external video

Fig. 246 Pop-up window for loading an external video

OXYGEN’s External video () option provides the possibility to:

  • Load an video file that was recorded with a 3rd party software in PLAY mode during analysis

  • Manually synchronize the video to the measurement data

  • Analyze both video and sensor data synchronized in OXYGEN

This feature was mainly developed to synchronize video data recorded with highspeed cameras to the sensor data but it can be used to load a video file from any camera into OXYGEN. The focus of the following section is on high speed video data.

Benefits:

  • Load videos from any camera into OXYGEN for analysis

  • Supported formats:

    • AVI (uncompressed)

    • MKV (VP8 and h264)

    • MP4 (h264)

  • No file size increment as only path to video file is stored to the .dmd-file

  • Support of various recording and trigger scenarios (see Possible Recording scenarios)

  • Adjustable playback speed (see Reviewing a Data File (PLAY mode))

  • Quick and easy reporting by exporting measurement screen to video (see Saving the screen as video)

Possible Recording scenarios

The section describes different scenarios to initiate the recording start of the DAQ system and the camera and lists certain advantages or disadvantages of the different methods.

Recording start of DAQ system and camera triggered by external signal

Recording start of DAQ system and camera triggered by external signal

Fig. 247 Recording start of DAQ system and camera triggered by external signal

An external signal / device is used to trigger the recording start of DAQ system and camera. The signal is normally a TTL signal with a rising edge to initiate the recording start.

Modern highspeed cameras provide trigger signal input. The DAQ system requires a digital signal input to acquire the signal and trigger the recording state. Analog inputs could be used as well.

Advantages:

  • Parallel recording start of camera and DAQ system without any latencies

  • Easy synchronization of sensor data and video data

  • No manual recording start on any device required

Disadvantage:

  • Separate hardware required for generating the trigger signal

Recording start of DAQ system triggered by camera

Recording start of DAQ system triggered by camera

Fig. 248 Recording start of DAQ system triggered by camera

The camera generates a TTL signal with rising edge at recording start which is forwarded to the DAQ system via the Trigger output of the camera. Modern highspeed cameras provide a trigger signal for triggering the recording state of 3rd party hardware. The DAQ system requires a digital signal input for acquiring the signal and triggering the recording state. Analog inputs could be used as well.

Advantages:

  • Parallel recording start of camera and DAQ system without any latencies

  • Easy synchronization of sensor data and video data

  • No separate hardware required for generating the trigger signal

Disadvantage:

  • Recording must be started manually for the camera

Recording start of camera triggered by DAQ system

Recording start of camera triggered by DAQ system

Fig. 249 Recording start of camera triggered by DAQ system

The DAQ system generates a TTL signal with Rising edge at recording start which is forwarded to the camera via an digital output of the DAQ system. Modern highspeed cameras provide a trigger signal input.

The operating system of the DAQ system will cause a delay between the DAQ system’s recording start and the instant of time the digital output is physically set to high which results in the recording start of the camera. This delay can be measured by recording the Digital Out channel. In real-life, a delay in the msec-range between DAQ system recording start and camera recording start will occur which can be compensated while loading the video into OXYGEN for post processing.

Advantages:

  • No separate hardware required for generating the trigger signal

  • Recording start of the DAQ system could be triggered

Disadvantages:

  • Deterministic latency between recording start of camera and DAQ system caused by the operating system

  • Latency needs to be compensated while loading and post processing the video

Manual Recording start of DAQ system and camera

Manual Recording start of DAQ system and camera

Fig. 250 Manual Recording start of DAQ system and camera

Recording is started manually both on the DAQ system and the camera.

Advantages

  • No separate hardware required for generating the trigger signal

  • No wiring between camera and DAQ system required

Disadvantages

  • Stochastic latency between recording start of camera and DAQ system caused by the operating system

  • Latency needs to be determined empirically and compensated while loading and post processing the video

Loading the external video into OXYGEN

Procedure to load an external video

Fig. 251 Procedure to load an external video

To load an external video proceed the following steps:

  • Go to the Channel List, press the + Button and select External Video (see ① in Fig. 251)

  • Click on Browse… to select the video file (see ② in Fig. 251)

  • Enter the native recording frame rate of the video (see ③ in Fig. 251)

  • Press Add to create a new video channel (see ④ in Fig. 251)

Synchronization of external videos

Compensating a deterministic delay between video and sensor data

Fig. 252 Compensating a deterministic delay between video and sensor data

If the latency between video and sensor data is known it can be compensated by entering the delay in Start Offset in the video’s channel setup (see ① in Fig. 252).

Positive offset denotes that OXYGEN data recording was started first and video data recording second.

Negative offset denotes that video data recording was started first and OXYGEN data recording second.

Manual delay compensation between video and sensor data

Fig. 253 Manual delay compensation between video and sensor data

If the latency between video and sensor data in unknown, the video timeline can be aligned to sensor data’s timeline by using the video instrument (see Video Instrument for details).

  1. Go to the measurement screen and drop the external video channel to the measurement screen (see ① in Fig. 253). This will create a video instrument including the video.

    The timebar shows the actual position of the video within the OXYGEN data file (see ② in Fig. 253)

  2. The buttons (see ③ in Fig. 253) can be used to change the position of the video within the data file

    <<< << < align with cursor >>> >> >

    • <<< Move the video +1 frame

    • << Move the video +10 frames

    • < Move the video +100 frames

    • Align with cursor: Move video start to actual cursor position

    • > Move the video -1 frame

    • >> Move the video -10 frames

    • >>> Move the video -100 frames

In general, the following workflow to manually align sensor and video data is recommended:

Alignment of sensor and video data

Fig. 254 Alignment of sensor and video data

  1. Use the Recorder to move the orange cursor to the reference event for data synchronization (see ① in Fig. 254)

  2. Press align with cursor to move the video start to the orange cursor position for a rough time adjustment (see ② in Fig. 254)

  3. For fine time adjustments, use the <<<, <<, < & >, >>, >>> buttons to align the timeline (see ③ in Fig. 254)

  4. When finished, the timebar can be hidden (see ④ in Fig. 254)

  5. The absolute time offset can also be seen in the video‘s channel setup (see ⑤ in Fig. 254)

  6. The settings can be saved to the data file (see ⑥ in Fig. 254)

Note

Only the file path to the video is stored to the OXYGEN data file but not the video itself.

Replaying the data file

Details can be found in Reviewing a Data File (PLAY mode).

Saving the measurement screen to video

Details can be found in Saving the screen as video.

Counter Channels in OXYGEN

OXYGEN supports three different Counter modes: Event Counting, Frequency determination and Encoder Mode (incl. X1, X2, X4 and A-up / B-down) counting.

The following extract from TRION module Technical Reference Manual provides an explanation of the different counting modes. For detailed information, refer to the TRION module Technical Reference Manual.

Counter Modes

Event counting

In Event Counting, the counter counts the number of pulses that occur on input A/B. At every acquisition clock, the counter value is read without disturbing the counting process.

Fig. 255 shows an example of event counting where the counter counts eight events on Input A or B. Synchronized Value is the value read by the TRION-CNT module at Acquisition Clock (encircled numbers in the figure, e.g. 1, 2).

Event Counting

Fig. 255 Event Counting

If counting at falling edges is necessary, the input signal must be inverted. This can be done directly in the software by selecting inverted input.

Frequency measurement

In general, it is possible to take the inverse of a period measurement to get the frequency of the input signal. If the period time measurement is done, an inaccuracy of counted internal time base cycles of ±1 cycle appears, because the counted cycles of the internal time base depend on the phase of the input signal with respect to the internal time base. For long period times, and therewith low frequencies, the measurement error is negligible. At high frequencies, and therewith short period times, few cycles are counted. In this case the error of ±1 cycle becomes significant.

Accuracy at period time measurement

Fig. 256 Accuracy at period time measurement

For higher precision result, a combination of main and sub counter is used internally for getting higher precision at the frequency measurement. The main counter is running on event counting (or encoder mode). The sub counter measures the time between. The sub counter measures exactly the time of the input event with a resolution of 12.5 ns relative to the acquisition clock. At every rising edge on Input A the counter value of the sub counter is stored in a register. At every Acquisition Clock (1, 2, …,6) the values of both counters are read out.

Frequency measurement

Fig. 257 Frequency measurement

Pulse width measurement

In Pulse Width Measurement the counter uses the internal time base to measure the pulse width of the signal present on Input A. The counter counts the rising edges of the internal time base after a rising edge occurs on Input A. At the falling edge on Input A the counter value is stored in a register and the counter is set to zero. With the next rising edge on Input A the counter starts counting again. At every Acquisition Clock ( 1 , 2 , …, 6 ) the register value is read out.

Fig. 258 shows a pulse width measurement.

Note

For measuring the low time of the signal, the input signal has to be inverted on the TRION-CNT module.

Pulse width measurement

Fig. 258 Pulse width measurement

Encoder

Motion encoders have usually three channels: channel A, B and Z. Channel A and channel B are providing the square signals for the counter and have a phase shift of 90°. With this phase shift, the decoder can recognize the rotation direction of the motion encoder. The third channel types out one pulse at a certain position at each revolution. This pulse is used to set the counter to zero. The amount of counts per cycle at a given motion encoder depends on the type of decoding: X1, X2, X4. All three types are provided by the TRION-CNT module. Some motion encoders have two outputs, which are working in a different way. Either channel A or channel B providing the square signal, depending on the direction of the rotation. Also, this type is supplied by the TRION-CNT module.

In the first case X1 decoding is explained. When Input A leads Input B in a quadrature cycle, the counter increments on rising edges of Input A. When Input B leads Input A in a quadrature cycle, the counter decrements on the falling edges of Input A. At every Acquisition Clock (1, 2, …, 9), the counter value is read out.

Fig. 259 shows the resulting increments and decrements for X1 encoding.

Quadrature Encoder X1 Mode

Fig. 259 Quadrature Encoder X1 Mode

For X2 encoding, the rising edges and the falling edges of Input A are used to increment or decrement. The counter increments if Input A leads Input B and decrements if Input B leads Input A. This is shown in Fig. 260.

Quadrature Encoder X2 Mode

Fig. 260 Quadrature Encoder X2 Mode

Similarly, the counter increments or decrements on each edge of Input A and Input B for X4 decoding. The condition for increment and decrement is the same as for X1 and X2.

Fig. 261 shows the results for X4 encoding.

Quadrature Encoder X4 Mode

Fig. 261 Quadrature Encoder X4 Mode

The third channel Input Z, which is also referred as the index channel, causes the counter to be reloaded with zero in a specific phase of the quadrature cycle.

Fig. 262 shows the results for X1 encoding with input Z.

Quadrature Encoder with channel Z

Fig. 262 Quadrature Encoder with channel Z

The A-Up/B-Down Encoder supports two inputs, A and B. A pulse on Input A increments the counter on its rising edges. A pulse on Input B decrements the counter on its rising edges. At every Acquisition Clock (1, 2, …, 9), the counter value is read out.

This situation is shown in Fig. 263.

A-Up/B-Down Encoder

Fig. 263 A-Up/B-Down Encoder

TRION Counter Overview

Table 27 TRION Counter overview

TRION

-CNT

-BASE

-TIMING

-VGPS

-1620-ACC

-2402-dACC

(3)-18x0-MULTI

-1802/1600-dLV

#Counter #Inputs/counter

6 3

2 3

1 3

1 3

1 1

2 1

2 1

1 3

Isolation

x

x

x

x

x

Trigger level

0 to 50 V / 12 mV steps

CMOS/TTL

CMOS/TTL

CMOS/TTL

70 % of input range

Progr. within input range

75 % of input range

CMOS/TTL

Event counting

Frequency/pulse width measurement

Encoder support

x

x

x

Angle determination (SW)

Speed determination (SW)

Sensor supply

5 and 12 V

5 and 12 V

5 and 12 V

5 and 12 V

x

x

x

5 and 12 V

As shown in Table 27, Frequency measurement and Event counting can be done with every TRION module with counter input. Encoders and CDM+Trigger sensors cannot be connected to a the TRION-1620-ACC or the TRION-2402-dACC module as they don’t have several digital input channels per counter channel. Hence, angle and rpm measurements are possible with a counter channel of a TRION-1620-ACC or TRION-2402-dACC module, but no turning direction can be determined.

Note

The Trigger Level supported by the TRION-2402-dACC module differs from the software possibilities.

Channel List of Counter Channels

Channel List of a Counter channel

Fig. 264 Channel List of a Counter channel

4 single sub-channels are created for each available Counter channel (COUNTER CNT 2/1 Sim in Fig. 264)in the Channel List. The counter hardware of one Counter channel (except TRION-dACC and TRION-ACC hardware) consists of two different counter logics, the Main counter and the Sub counter (see Fig. 265).

The first sub-channel (CNT 2/1 Sim in Fig. 264) is linked to the Main counter. If the Counter channel shall be used in the Event Counting or Encoder mode (X1, X2, X4, A-up/B-down), it must be defined in the Channel Setup of this sub-channel. The Frequency mode can be selected in this sub-channel as well, but this is only due to guarantee the compatibility with old setup files. The sub-channels 3 and 4 will disappear if the Frequency mode is selected (Angle_CNT2/1 Sim and Speed_CNT 2/1 Sim in Fig. 264).

The second sub-channel (Frequency_CNT 2/1 Sim in Fig. 264:) is linked to the Sub counter. This channel is used for the frequency measurement. If Frequency mode is selected in sub-channel one (CNT 2/1 Sim in Fig. 264), sub-channel two (Frequency_CNT 2/1 Sim in Fig. 264) is deactivated and does not display data.

The third sub-channel (Angle_CNT 2/1 Sim in Fig. 264) calculates the angle by using the data acquired from the Main counter and Sub counter logic and the fourth sub-channel (Speed_CNT 2/1 Sim in Fig. 264) calculates the speed by using the data acquired from the Main counter and Sub counter logic.

Block diagram of one Counter channel on a TRION-CNT module

Fig. 265 Block diagram of one Counter channel on a TRION-CNT module

Note

The maximum bus data rate of 90 MB/s is reached if 6 channels of a TRION-CNT module are stored with 2 MHz Sample Rate.

Channel Setup of a Counter Channel

Each of the four sub-channels has an own Channel Setup. The Channel Setups of all 4 sub-channels is summarized in the Channel Setup of the main counter channel (COUNTER CNT 2/1 Sim in Fig. 266) and can be entered by clicking on the gear button (see Fig. 266). The scaling of a sub-channel can be changed in the Channel Setup of the individual sub-channel.

Channel setup of a Counter channel

Fig. 266 Channel setup of a Counter channel

In the following, the Channel Setup of a Main Counter channel for and its options for an Event mode and an Encoder mode are explained on the example of a TRION-CNT module. Due to limited hardware possibilities, the channel setup of a TRION-ACC or TRION-dACC module counter channel provides less options.

Channel Setup for a TRION-CNT Channel in Event mode

Channel Setup for a TRION-CNT channel in *Event* mode

Fig. 267 Channel Setup for a TRION-CNT channel in Event mode

Table 28 Menu of a Counter channel in the Event mode

No.

Function

Description

Amplifier Options

1

Mode menu

Counter mode selection: Events, Frequency or Encoder

2

Threshold level

Threshold (Trigger) Level selection (depends on the TRION hardware, see Table 27)

3

Retrigger level

Retrigger Level selection (depends on the TRION hardware, see Table 27)

4

Filter menu

Selection of a digital filter; for additional information refer to Digital Filter of a Counter Channel

5

Coupling menu

Coupling (HP filter) selection (availability depends on TRION hardware)

Counter Group Settings

6

Type menu

Decoding type: Rotation or Linear decoding type

7

Pulses selection

Number of pulses transmitted by the counter per revolution, meter, …

8

Unit selection

Unit selection; for rotational sensors fixed to revolution, set to meters per default for linear sensors

9

Resample rate selection

Select the Resample rate here; needed if time synchronous counter and analog data is required. Enter the sample rate of the analog channel here and counter data will be time synchronous to the analog data

Signal Routing

10

Source_A selection

Select the input signal that shall be routed to Source_A

11

HW Reset button

HW reset selection; If this option is selected, a second input Source_Z must be selected. Source_A channel is reset if the edge of Source_Z raises from 0 to 1

12

Source_Z selection

Select the input signal that shall be routed to Source_Z (only applicable if HW Reset is selected)

13

SW Reset button

SW Reset selection; If this option is selected, Source_A is reset after the number of pulses entered in ⑦ is reached

14

Reset now button

If this button is pressed, a manual hardware reset is forced

15

Invert channel button

Inverts the respective input channel

Note

An automatic Counter Reset at Recording Start is not supported

Channel Setup for a TRION-CNT Channel in Encoder mode

Channel Setup for a TRION-CNT channel in *Encoder* mode

Fig. 268 Channel Setup for a TRION-CNT channel in Encoder mode

Table 29 Menu of a Counter channel in the Encoder mode

No.

Function

Description

Amplifier Options

1

Mode menu

Counter mode selection: Events, Frequency or Encoder

2

Threshold level

Threshold (Trigger) Level selection (depends on the TRION hardware, see Table 27)

3

Retrigger level

Retrigger Level selection (depends on the TRION hardware, see Table 27)

4

Filter menu

Selection of a digital filter; for additional information refer to Digital Filter of a Counter Channel

5

Coupling menu

Coupling (HP filter) selection (availability depends on TRION hardware)

Counter Group Settings

6

Type menu

Decoding type: Rotation or Linear decoding type

7

Pulses selection

Number of pulses transmitted by the counter per revolution, meter, …

8

Unit selection

Unit selection; for rotational sensors fixed to revolution, set to meters per default for linear sensors

9

Encoder Mode selection

Select the Encoder mode: X1, X2, X4, A-Up/B-Down

10

Resample rate selection

Select the Resample rate here; needed if time synchronous counter and analog data is required. Enter the sample rate of the analog channel here and counter data will be time synchronous to the analog data

Signal Routing

11

Source_A selection

Displays the signal that is routed to Source_A (routing can’t be edited in the Encoder mode)

12

Source_B selection

Displays the signal that is routed to Source_B (routing can’t be edited in the Encoder mode)

13

HW Reset button

HW reset selection; If this option is selected, a second input Source_Z must be selected. Source_A channel is reset if the edge of Source_Z raises from 0 to 1

14

Source_Z selection

Displays the signal that is routed to Source_Z (only applicable if HW Reset is selected, routing can’t be edited in the Encoder mode)

15

SW Reset button

SW Reset selection; If this option is selected, Source_A is reset after the number of pulses entered in ⑦ is reached

16

Reset now button

If this button is pressed a manual hardware reset is forced

17

Invert channel button

Inverts the respective input channel

Note

An automatic Counter Reset at Recording Start is not supported

Digital Filter of a Counter Channel

Each counter and digital input has a digital filter, which can be set to various gate times. If the gate time is set to “Off”, no filter is on the input signal. The filter circuit samples the input signal on each rising edge of the internal time base. If the input signal maintains his state for at least the gate time, the new state is propagated. As an effect the signal transition is shifted by the gate time.

Fig. 269 demonstrates the function of the filter.

Digital filter

Fig. 269 Digital filter

The intent of the filter is to eliminate unstable states, e.g. glitches, jitter… which may appear on the input signal, as shown in Fig. 270.

Input signal with chatter

Fig. 270 Input signal with chatter

It can be chosen between eight filter settings: Off, 100 ns, 200 ns, 500 ns, 1 μs, 2 μs, 4 μs and 5 μs. Two examples of filter settings are described. The 100 ns filter will pass all pulse widths (high and low) that are 100 ns or longer. It will block all pulse widths that are 75 ns or shorter. The 5 μs filter will pass all pulse widths (high and low) that are 5 μs or longer and will block all pulse widths that are 4.975 μs or shorter. The internal sampling clock (time base) is 80 MHz, so the period time amounts 12.5 ns. Pulse widths between gate time minus two internal time base period times may or may not pass, depending on the phase of the input signal with respect to the internal time base.

Properties of all filter settings:

Filter Gate Times

Fig. 271 Filter Gate Times

Supported Counter Sensors

Due to the software and TRION-hardware possibilities, OXYGEN supports three different types of counter sensors: Tacho sensors, CDM+Trigger sensors and Encoder sensors. The following table provides an overview about the possibilities and differences of the different types of sensors:

Table 30 Characteristics of Tacho, CDM+Trigger and Encoder sensors

Mounting

Connect

Pulses

Frequency

Required digital counter inputs

Measurement

RPM

Angle

Direction

Tacho

Easy

Analog or adj. CNT

1 kHz

0.1

1

x

x

CDM+ Trigger

Hard

CNT

360/720/xxx

125 kHz

2

x

Encoder coder

Hard

CNT

Up to 36000 and more

~100 kHz

3

Mandatory channel settings for Tacho sensors

Channel settings for a Tacho sensor

Fig. 272 Channel settings for a Tacho sensor

  • Amplifier Mode must be set to Events

  • Threshold and Retrigger Level must be adjusted depending on the sensor signal

  • Number of Pulses must be set to 1 pulse /revolution

  • Sensor signal must be routed to Source_A

Mandatory channel settings for CDM+Trigger sensors

Channel settings for a CDM +Trigger sensor

Fig. 273 Channel settings for a CDM +Trigger sensor

  • Amplifier Mode must be set to Events

  • Number of Pulses per revolution provided by the CDM signal must be entered

  • Route the CDM signal to Source_A and the Trigger signal to Source_Z (HW reset must be enabled)

Note

The Amplifier Mode can also be set to Encoder. In this case, the same settings as in Fig. 274 are mandatory. Note that the routing of the Source_A and Source_B input cannot be changed.

Mandatory channel settings for Encoder sensors

Channel settings for an Encoder sensor

Fig. 274 Channel settings for an Encoder sensor

  • Amplifier Mode must be set to Encoder

  • Number of Pulses per revolution provided by the Input_A and Input_B must be entered

  • The counting mode X1, X2, X4 or A-Up/B-Down must be selected

CAN Input Channels

The following TRION-boards provide one or several CAN ports

  • TRION-CAN: 2 or 4 ports

  • TRION(3)-18x0-MULTI: 1 CAN port

  • TRION-2402-MULTI: 1 CAN port

  • TRION-1600-1802-dLV-CAN: 1 CAN port

In addition, Vector devices from the VNxxxx series (i.e. VN1610 or VN7610) can be used for the CAN data acquisition as well. These devices are the dedicated hardware to also acquire CAN-FD data streams and can therefore be used for CAN data acquisition.

Note

The usage of Vector VNxxxx devices requires a separate software license.

CAN port configuration

To configure the CAN port properly, go to the Channel List and open the CAN port configuration of the dedicated CAN port by pressing the Gear button (see ① in Fig. 275).

CAN port configuration

Fig. 275 CAN port configuration

Note

When using the CAN port of a TRION(3)-18x0-MULTI or a TRION-2402—MULTI board, the CAN port is available on AI 1 of these boards. For accessing and using these CAN ports, you have to set the Input mode of AI 1 to CAN first and activate the dedicated CAN port second (see Fig. 276)

Using the CAN port of a TRION-MULTI board

Fig. 276 Using the CAN port of a TRION-MULTI board

The following settings are available:

  • Baud rate (see ② in Fig. 275):

    Select the proper Baud rate of the CAN bus here

  • Listen only (see ③ in Fig. 275):

    With the listen-only mode activated, normal bus activity can be monitored by the device. However, if an error frame is generated by the local CAN controller, it is not transmitted to the bus. Since in listen-only mode the module has no transmit function this feature must not be used in a point-to-point connection.

    For more information, refer to the to the TRION series technical reference manual which is available on the DEWETRON CCC-portal (https://ccc.dewetron.com/).

  • Termination (see ④ in Fig. 275):

    TRION-CAN ports offer a programmable termination resistance, either high impedance (False) or 120 Ω (True).

    For more information, refer to the to the TRION series technical reference manual which is available on the DEWETRON CCC-portal (https://ccc.dewetron.com/).

  • Autonomous Resend (see ⑤ in Fig. 275):

    Only affects CAN data output. For details, refer to CAN data recording.

  • Timestamp (see ⑥ in Fig. 275): Sets the time base on which the CAN signals are aligned.

    • 10 MHz:

      Assigns a timestamp with 100 ns resolution to the CAN messages and signals. This is the internal time base of the CAN port

    • AD sample rate:

      Assigns the timestamp of the highest analog sample rate to the CAN messages and sig-nals, i.e. 10 kHz analog sample rate results in a timestamp with 100 µs.

    • 100 Hz … 10 MHz:

      A user defined CAN timestamp resolution can be defined as well.

The frame preview (see ⑦ in Fig. 275) will show a preview of the received messages if all settings (especially Baud rate and Termination) are set correctly ad data is available on the CAN port.

Additional settings:

CPAD (see ⑧ in Fig. 275): If a module of the CPAD series is connected to the CAN bus, a CPAD decoder can be added for decoding their messages and signals without the need for a proper dbc-file. For more information, refer to Using CPADs with OXYGEN.

CAN data recording

After configuring the CAN port properly, the CAN stream must be decoded.

Decoding CAN data by using .dbc or .arxml files

The conventional way to decode the CAN data stream is to load either a dbc-file or an arxml-file which includes the information which CAN messages are included in the CAN data stream and how to decode them into CAN signals.

Thus, press Load DBC… (see ① in Fig. 277) or Load ARXML… (see ② in Fig. 277).

Decoding CAN data

Fig. 277 Decoding CAN data

A file dialog will open to browse and select the proper file.

Note

  • ARXML file decoding is supported in OXYGEN R5.6 or higher

  • ARXML file version 4.1 or high is required

After loading the dbc/arxml-file, a channel picker dialog will appear. It is possible to select only dedicat-ed CAN messages and signals for decoding or all channels contained in the file and press Ok afterwards.

CAN channel picker dialog

Fig. 278 CAN channel picker dialog

Note

The option Show only active messages performs a scan on the CAN bus to check which CAN messages are available on the CAN bus. You will only see the CAN messages and signals included in the dbc- or arxml-file that are currently available on the CAN bus when this option is activated.

After pressing Ok you will find the selected messages and signals in the channel list (see Fig. 279)

CAN messages and signals in the Channel List

Fig. 279 CAN messages and signals in the Channel List

You can delete all decoded messages and channels by pressing the Clear All button the CAN port config-uration (see ③ in Fig. 277).

If one or several messages available on the CAN bus should not be defined in the selected dbc- or arxml-file you can manually add them by pressing Add message channel (see ④ in Fig. 277) and defining the correct settings in the CAN message setup. More details can be found in CAN message setup.

Note

It is also possible to add and decode other CAN channels from a dbc- or arxml file during the data analy-sis (CAN offline decoding). To do so, the steps above have to be repeated within the loaded data file. The only condition is that the raw CAN data stream was stored during data recording.

CAN message setup

The CAN message setup can be accessed by pressing the gear button of the respective CAN message in the Channel List (see ① in Fig. 280).

CAN message channel setup

Fig. 280 CAN message channel setup

The following CAN message settings can be edited here if certain settings in the loaded dbc-file were defective:

  • Protocol type (see ② in Fig. 280): CAN or J1939 or CAN-FD (if applicable)

    For additional information about SAE J1939 data decoding, refer to section 4.

  • Message ID (see ③ in Fig. 280): The message’s ID can be set from 0x00 to 0x7ff

  • Message Type (see ④ in Fig. 280): Standard or Extended

  • DLC (see ⑤ in Fig. 280): The DLC can be set from 0 … 8 (…64 for CAN-FD)

  • Mode (see ⑥ in Fig. 280): The Mode can be set from Receive (Receiving CAN data) to Transmit (Outputting OXYGEN data over CAN).

    For additional information, please refer to section 5.

  • Add signal channel (see ⑦ in Fig. 280):

    If the CAN message includes one additional signal which is not loaded from the dbc-or arxml-file or available within the dbc-file, a new signal can be added. The signal’s setting are described in CAN signal setup.

CAN signal setup

The CAN signal setup can be accessed by pressing the gear button of the respective CAN signal in the Channel List (see ① in Fig. 281).

CAN signal setup

Fig. 281 CAN signal setup

The following CAN signal settings can be edited here if certain settings in the loaded dbc-file were defective:

  • Data format (see ② in Fig. 281): Intel or Motorola

  • Data type (see ③ in Fig. 281): Double, Float, Signed Integer or Unsigned Integer

  • Start bit (see ④ in Fig. 281): Define the start bit of the signal within its message

  • Length (see ⑤ in Fig. 281): Define the length of the signal within its message

  • Signal Type (see ⑥ in Fig. 281): Regular, Multiplexed or Multiplexor

  • DBC Scaling (see ⑦ in Fig. 281): Change the scaling of the signal

  • Preview: (see ⑧ in Fig. 281): The preview shows the past 10 seconds of the signal to check if proper settings have been applied to the signal.

CAN data decoding using the CAN editor

Instead of using .dbc or .arxml files for data decoding it is also possible to add CAN messages and signals manually. OXYGEN provides a CAN editor for this purpose which can be opened by pressing the Messages & signal button the CAN port configuration (see ① in Fig. 282):

CAN port configuration

Fig. 282 CAN port configuration

CAN editor overview

Fig. 283 CAN editor overview

The CAN editor can be used to

  • Manually add or delete CAN messages and signals (see ① in Fig. 283)

  • Rename the currently selected CAN message and signal (see ② in Fig. 283)

  • Add comments to messages and signals (see ③ in Fig. 283)

  • Edit CAN messages and access the same settings as described in section CAN message setup (see ④ in Fig. 283)

  • Edit CAN signals and access the same settings as described in section 3.3 (see ⑤ in Fig. 283)

  • Set the CAN Message mode to Receive for acquiring data or transmit for outputting OXYGEN da-ta over CAN (see ⑥ in Fig. 283)

  • Providing a preview of the past 10 seconds of the signal to check if proper settings have been applied to the signal (see ⑦ in Fig. 283)

When finished you can exit the CAN editor again by pressing the Close button (see ⑧ in Fig. 283).

Note

The CAN editor and the related CAN message / signal setup is also available for CAN-FD streams.

SAE J1939 DATA DECODING

SAE J1939 is an overlay of standard CAN for primary use in heavy duty vehicles. It uses a standardized messaging system with parameter group numbers encoded in the extended message frame ID.

Main properties

  • Message ID consists of

    • PGN-Number

    • Priority and

    • Source address

  • Messages can be longer than standard CAN Frame size due to Multi Frame Messaging system

Decoding of J1939 messages

A simple CAN decoder could receive and decode messages with standard length when the decoder is parametrized with the exact message id. When it comes to practical use, and the user wants to decode and read data with different priority and/or source address, it gets difficult. Also the reading of multi frame messages is not possible with standard tools. OXYGEN supports the Multi Frame Messages as well as decoding messages with varying priority and source address.

Example: DBC-File defines the following Message ID: 0x0CF004FE

  • PRIORITY (Encoded) = 0x0C >> bit shift 2 = 0x03 (=3)

  • PGN-Number = 0xF004 (=61444)

  • Source Address = 0xFE (=254, broadcast)

If a message on the CAN has the following Message ID: 0x18F00400

Standard CAN-Decoder would recognize a different message and does not decode it (because the message ID is not identical to the defined one)

To decode it anyway, OXYGEN ignores the priority and the source address (if it is originally defined as 0xFE)

Table 31 Decoding of J1939 messages in OXYGEN

Frame Description (DBC)

Decoded in OXYGEN

PRIO/PGN/SA=0xFE

0x*PGN** (only PGN matters, source address and priority is ignored)

PRIO/PGN/SA≠0xFE

0x*PGN*SA (PGN and Source Address matters, priority is ignored)

Supported DBC-Formats for Description of J1939 Messages (Requirements):

Correct Specification of the VFrameFormat [J1939 PG (ext. ID)]

BA_DEF\_ BO\_ "VFrameFormat" ENUM  "StandardCAN","ExtendedCAN","reserved","J1939PG"; BA_DEF_DEF\_ "VFrameFormat" "J1939PG"; BA\_ "ProtocolType" "J1939";

Each Message must have the VFrameFormat Property 3 (according to ENUM)

BA\_ "VFrameFormat" BO\_ 2633805054 3;

The “Old” format (J1939 PG) is not supported, ask our support, how to convert it to the newer format (J1939 PG (ext. ID)).

Replace Source Address:

If a dbc- or arxml file is loaded that contains J1939 messages, the source Address will be displayed when Show only active messages is activated (see ① in Fig. 284). By Selecting Replace Address it is possible to replace the current source address of the dedicated mes-sage by a user defined one (see ② in Fig. 284).

Channel picker for SAE J1939 messages and signals

Fig. 284 Channel picker for SAE J1939 messages and signals

CAN-OUT - transmitting OXYGEN data via CAN

Note

This is an optional feature and requires a license.

It is possible to transmit OXYGEN channels cyclically over the CAN bus. This functionality is supported by all CAN ports available on the different TRION boards and also by the Vector VN series’ CAN ports. For transmitting CAN data, it is either possible to load a dedicated dbc file or to define the CAN messag-es and signals individually by using the CAN editor. To transmit OXYGEN data over CAN, the CAN message Mode must be set to Transmit (see ① in Fig. 285) for that.

CAN output settings

Fig. 285 CAN output settings

The output rate can be defined from 0.1 … 100 Hz (see ② in Fig. 285) individually for each message. The output delay can be set from 1 … 500 ms (see ③ in Fig. 285). One dedicated OXYGEN scalar time domain channel (i.e. Analog or Digital input, power value such as Active power or another CAN channel) can be assigned to one CAN signal by dropping the channel or typing its name into the Transmission Settings (see ④ in Fig. 285).

Note that the preview will not show the currently transmitted data but has no functionality when the message mode is Transmit.

The Autonomous Resend option (see ① in Fig. 286) provides the following functionality for CAN buses which transmit data:

  • False (Default): The transceiver only sends the data once no matter if the receiver send an acknowledgement or not and sends the next message right afterwards. This makes the CAN da-ta transmission more deterministic on a correctly terminated CAN bus. But there is a remaining risk that a messages gets lost.

  • True: The risk of losing messages during transmission is low as message is resend in case no acknowledgement is sent by the receiver. But the risk of colliding messages of several trans-ceivers is higher.

Autonomous resend option

Fig. 286 Autonomous resend option

To tune the responsiveness and the signal quality of the transmitted data, we introduced the Out delay (see ③ in Fig. 285). This is the time, which the data is delayed before sent. The following graphs show the difference between two individual settings:

Blue: Analog Input; Green: CAN-Output with a delay of 70 ms (default value)

Fig. 287 Blue: Analog Input; Green: CAN-Output with a delay of 70 ms (default value)

Blue: Analog Input; Green: CAN-Output with a delay of 10 ms

Fig. 288 Blue: Analog Input; Green: CAN-Output with a delay of 10ms

It is visible that a sample is repeated in case the delay is too low and no updated data is available yet.

Note

  • Message and Signal Encoding

    The signals are encoded with the data type and length defined in the dbc-file or in the CAN sig-nal setup. If the channel has a value higher (or lower) than the possible range, the max (or min) value will be transferred. Make sure, you selected the right range and resolution for the specific channel not to lose information.

  • No channel assigned to a signal: the value 0 (Zero) is transmitted

  • Channel data is NaN: NaN is transmitted in case of float or double, 0 is transmitted in all other cases

GPS channels

The following GPS data channels can be acquired by a TRION-TIMING or TRION-VGPS-20/-100 module:

Table 32 Available GPS channels

Default channel name

Channel mode

Channel description

Range

Unit

Data type

Scaling available

GPS

NMEA

GPS NMEA channel

String

x

Latitude_GPS

Latidtude

Current latitude of the object

-90° … 90°

°

Double

Longitude_GPS

Longitude

Current longitude of the object

-180° … 180°

°

Double

Altitude_GPS

Altitude

Current altitude of the object

-100 m … 1000 m

m

Double

Velocity_GPS

Velocity

Current velocity of the object

0 km/h … 300 km/h

km/h

Double

Heading_GPS

Direction

Current heading of the object

0° … 360°

°

Double

Satellites_GPS

Sat

Number of satellites in view

0 … 24

Double

x

Fix Quality_GPS

Quality

GPS Fix

String

x

H.Dilution_GPS

HDOP

2D deviation of longitude and latitude

0 m … 100 m

m

Double

SoD_GPS

Second

Current second of the day

0 s … 86400 s

m

Double

x

Date_GPS

Date

Current date in the format yyy-mm-dd hh:mm:ss:ms

String

x

Acceleration_GPS

Acceleration

Current acceleration of the object

-1000 m/s²… 1000 m/s² …

m/s²

Double

Distance_GPS

Distance

Distance covered from start of measurement

0 m … 1000000 m

m

Double

Table 33 GPS channel type

Default channel name

Acquired from TRION hardware

Calculated channel

Calculation

GPS

x

Latitude_GPS

x

Longitude_GPS

x

Altitude_GPS

x

Velocity_GPS

x

Heading_GPS

x

Satellites_GPS

x

Fix Quality_GPS

x

H. Dilution_GPS

x

SoD_GPS

x

Date_GPS

x

Acceleration_GPS

x

Differentiation of channel Velocity_GPS

Distance_GPS

x

Integration of channel Velocity_GPS

Note

  • The ranges of the channels are defined per default and have the purpose to define a min/max value if the channels are displayed in an Instrument. The ranges are neither minimum nor maximum limits. Thus, the defined ranges can be overrun and underrun without “clipping”.

  • Channels of data type double with physical unit can optionally be scaled (see ⑰ in Fig. 134). This option might be used for changing the physical channel unit from (kilo)meters to miles or km/h to mph.

  • Channels of data type double can be assigned to mathematical formulas (see Formula channel) or statistics calculations (see Statistics channel).

  • GPS channels cannot be filtered (see Filter channel) as these channels are asynchronous channels.

  • During the measurement it might happen that the GPS Fix Quality is not fix all the time (i.e. GPS connection is lost during a ride through a tunnel). If this happens, the last value of the GPS channels will be hold until the GPS Fix Quality will be fix again and a new value is received.

  • If the GPS Fix Quality is not fix for more than 60 seconds, the calculated channels Acceleration_GPS and Distance_GPS will change to NaN until the GPS Fix Quality is fix again.

  • The GPS Fix Quality is fix if the channel receives 1 (GPS fix), 2 (Differential GPS fix), 3 (PPS fix), 4 (Real Time Kinematic) or 5 (Float RTK). The GPS Fix Quality is not fix if the channel receives 0 (Fix not available), 6 (Estimated (dead reckoning)), 7 (Manual input more) or 8 (Simulation mode)

The individual channels can be assigned to the following Instruments:

Table 34 GPS channels - compatible instruments

Default Channel Name

GPS plot

Analog Meter Digital Meter Bar Meter Indicator

Recorder Chart Recorder

Table

Scope

XY plot

GPS*

x

x

x

x

x

Latitude_GPS

Longitude_GPS

Altitude_GPS

x

Velocity_GPS

x

Heading_GPS

Satellites_GPS

x

Fix Quality_GPS

x

x

x

x

x

x

H.Dilution_GPS

x

SoD_GPS

x

Date_GPS

x

x

x

x

x

x

Acceleration_GPS

x

Distance_GPS

x

*The channel GPS can be dragged and dropped directly from the Channel List to the measurement screen. If this is performed, the current value of the channels Latitude, Longitude, Altitude, Velocity, Heading, Satellites used, Quality and Dilution will be displayed (see Fig. 289).

Drag and drop the GPS channel to the measurement screen

Fig. 289 Drag and drop the GPS channel to the measurement screen

Note

During GPS-channel analysis in PLAY mode, the GPS channels can also be exported to *.txt, *.csv, *.mdf4 or *.mat format (see Export Settings). Please note that GPS-Channels of data type String can only be exported to *.txt or *.csv format as the data type is not supported for *.mdf4 and *.mat format.

TEDS support

TEDS stands for Transducer Electronic Datasheet and is used to identify and apply settings from a sensor directly without manually entering them. The following TRION(3) modules support TEDS:

  • TRION(3)-18xx-MULTI

  • TRION-2402-MULTI

  • TRION-2402-dACC1

1TEDS functionality only supported in IEPE® mode.

Use in OXYGEN

If a sensor with TEDS interface is connected to an according TRION(3) module, the TEDS interface is automatically detected and the settings are applied to the channel.

To scan for a TEDS interface, also on multiple channels, there is a button Scan TEDS on the lower edge of the channel list menu, seen in Fig. 290. Whenever the full channel list menu is open, the scan for TEDS is done continuously and a manual scan is not necessary when the sensor is changed. This is not the case for the TRION-2402-dACC, where the scan must be done with the button in order to scan for TEDS.

It is also possible to disable the TEDS detection by choosing one or multiple channels in the channel list and clicking on the button Disable TEDS, also seen in Fig. 290. After disabling the TEDS detection, all set settings from the TEDS are deleted and can be entered manually.

Channel List Menu and TEDS scanning

Fig. 290 Channel List Menu and TEDS scanning

A detailed channel setting can be seen in Fig. 291. Depending on the type of sensor some settings might vary. The settings from the TEDS can be seen here and some settings can be adjusted manually, like the range. By clicking on the shown TEDS serial number, marked red in Fig. 291, all the TEDS information and settings can be seen (Fig. 292).

Detailed Channel Settings with TEDS interface

Fig. 291 Detailed Channel Settings with TEDS interface

TEDS information

Fig. 292 TEDS information

More information about the set scaling can be found in the Sensor Scaling section by switching to the TEDS tab. This cannot be changed and is only for information for the user. However, it is possible to add an additional scaling in the General tab, which will be used additionally to the already set scaling from the TEDS.

Sensor Scaling Information: TEDS

Fig. 293 Sensor Scaling Information: TEDS

TEDS detection can also be disabled in the detailed settings by clicking on the green TEDS button (marked green in Fig. 291). This button has different colors depending on the state, which will be explained here:

  • green TEDS active; sensor was detected and is in use.

  • grey TEDS active; no sensor was detected.

  • red TEDS active; sensor was detected but is not compatible, remove the sensor or disable TEDS.

    This case is also shown in the channel list:

    Channel list
  • orange TEDS active, sensor lost and not detected anymore

  • grey_cross TEDS disabled

Loading a setup

When loading a setup, OXYGEN automatically checks the if the same TEDS can be detected on the current system. If there is a mismatch in the TEDS detection, this specific channel or rather TEDS type is marked red. If a new sensor is detected, the new detected TEDS will be marked red, seen in Fig. 294 and the new settings of the sensor can be applied by clicking on Apply of the pop-up window. Otherwise, the remapping must be cleared and the channels, on which the settings should be applied, must be remapped manually, seen in Fig. 295. If a sensor from the setup file is missing and is not detected when loading the file, the TEDS type will show the message missing, seen in Fig. 296.

Hardware Mismatch: different TEDS were detected

Fig. 294 Hardware mismatch: different TEDS were detected

Hardware mismatch: manual remapping of TEDS

Fig. 295 Hardware mismatch: manual remapping of TEDS

Hardware mismatch: missing TEDS in loaded setup file

Fig. 296 Hardware mismatch: missing TEDS in loaded setup file