Instruments and instrument properties

Adding an instrument to the measurement screen and channel assignment

Adding Instruments to the measurement screen

Fig. 297 Adding Instruments to the measurement screen

To add an Instrument to the measurement screen, the user must click on the Instruments menu and open it while a measurement screen is open. Select the desired Instrument by clicking on it (①), move it to the measurement screen by keeping the mouse button pressed (②) and place it wherever you like by releasing the mouse button (③). In the example of Fig. 297, an Analog meter is added to the measurement screen. The Instruments are aligned to the grey grid in the screen background. The Design mode is automatically activated when an Instrument is added to the measurement screen. The user can see that the Design mode is activated because of the blue background of the Design mode button (④) and because of the grey grid in the background of the measurement screen.

In the Design mode, the user can now change the size of the Instrument by moving the black corners of the Instrument or change the position of the Instrument by grabbing it at the blue frame.

Note

  • Several Instruments on the screen can be selected by drawing a selection rectangular with the left mouse button like it is known from Windows Explorer or similar (see Fig. 298) or by keeping CTRL+SHIFT pressed while selecting the Instruments. All Instruments on a measurement screen can be selected by pressing CTRL+A.

    Selection of several Instruments in the Design Mode

    Fig. 298 Selection of several Instruments in the Design Mode

  • It is possible to activate the Design mode in the LIVE mode as well as in the REC mode and in the PLAY mode.

To assign a data channel to an Instrument, the user can select the desired channel in the Data Channel menu (⑤) by just clicking on it when the respective Instrument is selected in the measurement screen.

The functionality and properties of the individual Instruments will be explained in the following sections in detail.

As explained above, the user can add and modify the instruments on the measurement screen when the Design mode is activated. The user can also delete Instruments from the screen by selecting them and clicking on the rubbish bin (⑥) next to the Instruments menu or by grabbing the respective Instrument and move it to the rubbish bin or by selecting the Instrument and pressing the DEL-key. To exit the Design mode again, the user must click on the Design mode button and the grey grid on the background of the measurement screen will disappear. The Clear button (⑦) will erase all Instruments from the currently displayed measurement screen. The Clear All button (⑧) will erase all Instruments from all measurement screens.

Note

Pressing the Clear and the Clear all button can NOT be reverted.

Analog meter

Analog meter - Overview

Fig. 299 Analog meter - Overview

The Analog meter can be set up in quite a few different ways. The screen capture to the right shows the various customizable Instrument Properties for this display and they are as follows:

  • Four different visualization options for the indicator:

Analog meter - visualization options

Fig. 300 Analog meter - visualization options

  • Range settings: The user has the options of using auto range or a user defined range.

  • Limits: Allows users to color the dial based on different limit values. The user also has the option to colorize the indicators needle which helps in identifying signals which have hit a limit. This is illustrated in the screen capture.

  • Display Value: The Instruments displays either the actual channel value or the Average, RMS, ACRMS, Min, Max or Peak2Peak value at a user defined time interval of 0.1s, 0.25s, 0.5s, 1.0s.

  • Style: The user can specify the number of columns for an Analog meter cluster if several channels are selected. Selection of a transparent or untransparent background.

  • Layer: Moves the Instrument in front of or behind another object (only applicable in Design Mode).

Note

Up to 96 channels can be assigned to one single Analog Meter.

Digital meter

Digital meter – overview

Fig. 301 Digital meter – overview

The Digital meter provides the user with the ability to definitively and quickly see what is going on with a measurement channel. This capability is further enhanced with the following list of features:

  • Limits: Allows users to color the Digital meters’ text based on different limit values. This really helps in identifying signals which have hit a limit when the display is very “busy”. This is illustrated in the screen capture.

  • Number Format: This option gives the ability to either display the shown values in Scientific or Decimal format.

  • Precision: Number of decimals right to the right of the comma can be entered here

  • Minimum digits: Minimum number of digits can be entered here; If the measurement value exceeds the number of digits, it will be displayed anyway but the font size will be decreased

  • Select suitable unit: a suitable unit prefix (i.e. milli or kilo) will be automatically selected if it makes sense in case this option is selected

  • Display Value: The Instrument displays either the actual channel value or the Average, RMS, ACRMS, Min, Max or Peak2Peak value at a user defined time interval of 0.1s, 0.25s, 0.5s, 1.0s.

  • Style: The user can specify the number of columns for a Digital meter cluster if several channels are selected. Selection of a transparent or untransparent background.

  • Show border: A grey line is drawn between the single measurement channels in case this option is selected.

  • Layer: Moves the Instrument in front of or behind another object (Only applicable in Design Mode).

Note

Up to 96 channels can be assigned to one single Digital Meter.

Recorder

Recorder - Overview

Fig. 302 Recorder - Overview

This Instrument replicates the functionality of a strip chart recorder in combination with many additional features.

Note

Up to 8 channels can be assigned to one single Recorder.

Instrument properties

The following properties can be manipulated via the Instrument Properties menu:

  • Time Axis: This property changes the format of the X-axis. The user can select between Auto, Absolute time and Relative time.

  • Auto: In Sync Mode, the Auto time format is the Absolute time, otherwise the Auto time format is the Relative time

  • Absolute time: The unit of the X-axis is the actual time of day set in the OS settings

  • Relative time: The unit of the X-axis is the relative time starting with 0:00 for every new measurement

  • Cursors: Select the individual parameters that are calculated when the cursors are used. For the detailed cursor description refer to section Activate cursors.

  • Value Axis: This property allows the user to specify the range on the Y-axis.

  • When the option Individual Scaling is selected, the scaling can be changed individually per channel and each channel will have an own Y-axis. If it is deselected, all channels will have one common Y-axis. For further scaling details, please refer to Quick selection Y-axis scaling.

  • If Automatic Scaling is selected, the Y-axis will always be adjusted to the actual displayed data minimum and maximum.

  • Displaying Event markers (see section 8) can be deactivated with the checkbox Show Event markers.

  • The Recorder shows only statistics data if Show only statistics data is selected. The statistics data to be displayed can be selected from the dropdown above. Statistics Recording (see section 7) had to be enabled during recording for using this option.

  • Style:

    • It is possible to select a transparent or intransparent background

    • Events Markers can optionally be hidden

    • The Line Width can be set from 1…10

    • The granularity of the time axis scaling can be changed

    • In case of triggered recording, the type of statistical data to be visualized can be selected (when no waveform data is available)

    • Statistics Data only can optionally be displayed

    • If Show data labels is selected, a window will display the nearest measurement value and time if the mouse is within the recorder (see Fig. 303).

      Mouse-over information

      Fig. 303 Mouse-over information

  • Layer: Moves the Instrument in front of or behind another object (only applicable in Design Mode)

Linking the time axis of several recorders

It is possible to link the time axis of several adjacent Recorders or the time axis of all Recorders on one page. This simplifies time zooming operations with several Recorders tremendously. This can be selected in the Link mode dropdown menu available in the Instrument properties (see Fig. 304) and must be selected for each Recorder separately.

Recorder link mode

Fig. 304 Recorder link mode

The selected link mode is denoted in the lower left side of each Recorder: “Pag” for Instruments on Page and “Lnk” of Adjacent Recorders.

Additional properties

To use further functionality of this instrument, the Design mode must be left. The following additional features are available:

Additional features of the Recorder

Fig. 305 Additional features of the Recorder

  1. Quick selection X-axis scaling

  2. Quick selection Y-axis scaling

  3. Activate cursors

  4. Quick expansion button

  5. Pinch/Scroll zoom feature

Quick selection X-axis scaling

This property menu appears via left click or touch and hold the X-axis of the recorder. By dragging your clicked mouse cursor or your finger into one of these menu fields and releasing you will select a new range setup. The user can select the following options:

  • Full: Sets the time axis of the recorder to the total elapsed recording time

    Note

    By one right click on the X-axis, the total elapsed recording time will be displayed as well.

    Changing the X-axis scaling to the full time with one right click

    Fig. 306 Changing the X-axis scaling to the full time with one right click

  • 1 min: Sets the time axis of the recorder to a one-minute window of the current recording time

  • 1 h: Sets the time axis of the recorder to a one-hour window of the current recording time

  • 12 h: Sets the time axis of the recorder to a twelve-hour window of the current recording time. If your current recording duration is below twelve hours, you will see negative time within your recorder if Relative time is selected in the Time Axis properties.

  • Custom: Possibility to select an individual time window:

    Window to define a customized X-axis scaling

    Fig. 307 Window to define a customized X-axis scaling

Useful shortcuts

  • Scrolling with the mouse wheel will zoom into the X-axis

  • Pressing the Shift key while scroll zooming will accelerate your zooming speed

  • Right clicking and dragging across the Recorder will allow the user to zoom into a specific region of the recorder (only available during recording or in freeze mode)

  • Performing a single right click will un-zoom the users Recorder instrument one step at a time

Quick selection Y-axis scaling

This property menu appears via left click or touch and hold the Y-axis of the recorder. By dragging your clicked mouse cursor or your finger into one of these menu fields and releasing, you will select a new range setup. The user can select the following options:

  • Overall min/max: Will set the range of all channels in the recorder to min/max value range of the highest signal amplitude displayed in the recorder

  • Overall full range: Sets the range of all channels in the recorder to the specified range of the channel with the highest range settings.

    Note

    This Scaling option is also accessible by pressing the CTRL key and clicking on a channel name.

  • Individual full range (Only available when Individual scaling is selected in the Instrument Properties): Sets the range of all channels assigned to the recorder to their individual full range values.

  • Individual min/max (Only available when Individual scaling is selected in the Instrument Properties): Sets the range of all the channels assigned to the recorder to their own individual min/max values.

  • A click on the individual channel name will only set the selected channel to its individual min/max value. This scaling option is also possible by clicking on the channel name on the Y-axis

  • Custom: (Only available when Individual scaling is not selected in the Instrument Properties): Possibility to define a customized range for the Y-axis that will affect all plotted signals:

    Window to define a customized Y-axis scaling (Individual Scaling selected)

    Fig. 308 Window to define a customized Y-axis scaling (Individual Scaling selected)

Example: Two channels are displayed in one Recorder. Channel 1 has a Signal Input Range of ±10 V and the range of the currently displayed data is ±8 V. Channel 2 has a Signal Input Range of ±3 V and the range of the currently displayed data is ±2 V.

  • Clicking on Overall min/max: The scaling of both channels is set to ±8 V

  • Clicking on Overall full range: The scaling of both channels is set to ±10 V.

  • Clicking on Individual full range: The scaling of channel 1 is set to ±10 V and the scaling of channel 2 to is set to ±3 V

  • Clicking on Individual min/max: The scaling of channel 1 is set to

  • Clicking on the name of Channel 1

    • will set the scaling of Channel 1 to ±8 V and not affect the scaling of Channel 2 if Individual scaling is selected

    • will set the scaling of the Y-axis to ±8 V if Individual scaling is de-selected

  • Clicking on the name of Channel 2

    • will set the scaling of Channel 2 to ±2 V and not affect the scaling of Channel 1 if Individual scaling is selected

    • will set the scaling of the Y-axis to ±2 V if Individual scaling is de-selected

Note

When Individual scaling is selected, the Custom option will not be available by clicking on the Y-axis and keeping the mouse button pressed. To enter this pop-up window when Individual scaling is selected, click on the min/max value of the Y-axis scaling:

Define a customized Y-axis scaling for one channel (Individual Scaling not selected)

Fig. 309 Define a customized Y-axis scaling for one channel (Individual Scaling not selected)

If several channels are displayed and the scaling of all channels shall be set to the same range, click on the min/max scaling of one channel while keeping the CTRL key pressed and the scaling menu will appear as well. In this case the settings will be assigned to all displayed channels:

Define a customized Y-axis scaling for all channels (individual scaling not selected)

Fig. 310 Define a customized Y-axis scaling for all channels (individual scaling not selected)

Useful shortcuts

  • Pressing the CTRL key while scrolling with the mouse wheel will zoom into the Y-axis.

  • Pressing the Shift key while scroll zooming will accelerate your zooming speed

  • Right clicking and dragging across the Recorder will allow the user to zoom into a specific region of the recorder (only available during recording or in freeze mode and if Automatic Scaling is not selected)

  • Performing a single right click will un-zoom the users Recorder instrument one step at a time

  • Right clicking on a channel along the Y-axis will set the channels’ maximum and minimum value to the channels full range which is dictated in that channel’s setup page

Activate cursors

Activated cursors - overview

Fig. 311 Activated cursors - overview

This option is only available in the PLAY mode or if the measurement screen is frozen. After activating the cursors, cursor A and B will appear in the recorder window and a table that contains the actual position of both cursors, the respective signal value on the cursor positions and the difference Delta between the cursor positions will appear below the Recorder (see Fig. 311).

Delta = \ \text{Time}_{\text{CursorB}} - \text{Time}_{\text{CursorA}}\ \lbrack s\rbrack

The position of the cursors can be changed by moving them to the left and right.

Renaming the cursors
Renaming the cursors

Fig. 312 Renaming the cursors

A click on the cursor name (see red arrow in Fig. 312) opens a popup with the possibility to enter a specific instant of time where the cursor shall be placed at and to change the Cursor Name. This applicable for cursor A and B. If several Recorders are used, the cursors of each Recorder can be renamed individually. If the cursors are deactivated and activated again, the individual names will be stored.

Measurement capabilities by using cursors

Additional information can be displayed in the table by selecting it in the CURSORS section in the Instrument Properties (see Fig. 311). The additional values are the following:

  • Max: Displays the maximum signal level between cursor A and cursor B

    \text{Max} = \text{Max}\left\{ \text{Signallevel}_{i} \right\}\ \lbrack\text{Unit}\rbrack

  • Avg: Calculates the arithmetic mean value respecting the signal level from cursor A to cursor B according to the following formula:

    \text{Mean} = \frac{1}{N}\sum_{i = 1}^{N}{\text{Signalleve}l_{i}}\ \lbrack\text{Unit}\rbrack

  • Slope: Calculates the slope of the signal between cursor A and cursor B according to the following formula:

    \text{Slope} = \ \frac{\text{Signallevel}_{\text{CursorB}} - \text{Signallevel}_{\text{CursorA}}}{\text{Delta}}\ \left\lbrack \frac{\text{Unit}}{s} \right\rbrack

  • Min: Displays the minimum signal level between cursor A and cursor B

    \text{Min} = \text{Min}\left\{ \text{Signallevel}_{i} \right\}\ \lbrack\text{Unit}\rbrack

  • RMS: Calculates the quadratic mean value respecting the signal levels from cursor A to cursor B

    \text{RMS} = \ \sqrt{\frac{1}{N}\sum_{i = 1}^{N}\left( \text{Signallevel}l_{i} \right)^{2}}\ \lbrack\text{Unit}\rbrack

  • Frequ.: This value is the reciprocal value of Delta.

    \text{Frequ}. = \ \frac{1}{\text{Delta}}\ \ \left\lbrack \frac{1}{s} = \text{Hz} \right\rbrack

  • Integral: Calculates the area within the Y-axis and the signal from cursor A to cursor B according to the following formula:

    \text{Integral} = \ \text{Mean}*\text{Delta}\ \lbrack\text{Unit}*s\rbrack

  • C/D-cursors: Adds two additional cursors that can be moved vertically (not available for a Chart Recorder)

    • TimeCursorA… Instant of time at position of cursor A

    • TimeCursorB… Instant of time at position of cursor B

    • SignalLevelCursorA…. Level of the signal at position of cursor A

    • SignalLevelCursorB…. Level of the signal at position of cursor B

    • SignalLeveli…. Signal level at position i between cursor A and B

    • i = 1…N

    • i = 1 =: Cursor A

    • i = N =: Cursor B

The following example of a 0.5 Hz sine wave that was sampled with 10 Hz will demonstrate the calculations:

0.5 Hz sine wave in a Recorder; Cursor A @ 0.1s and cursor B @ 2.0 s

Fig. 313 0.5 Hz sine wave in a Recorder; Cursor A @ 0.1s and cursor B @ 2.0 s

In table format, the signal looks as follows:

Table 35 0.5 Hz sine wave sampled with 10 Hz in table format

i = 1…20; N = 20

Time [s]

Sine 0.5 Hz [V]

Cursor A

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9

0.309017 0.587785 0.809017 0.951057 1.000000 0.951057 0.809017 0.587785 0.309017 0.000000 -0.309017 -0.587785 -0.809017 -0.951057 -1.000000 -0.951057 -0.809017 -0.587785 -0.309017

Cursor B

20

2.0

0.000000

In the following section, the values displayed with the cursors are calculated for this signal and can be compared with the OXYGEN results in Fig. 313.

  • Delta:

    \text{Delta} = \ \text{Time}_{\text{CursorB}} - \text{Time}_{\text{CursorA}} = 2.0s - 0.1s = 1.9s

  • Max:

    The maximum value between cursor A and B is 1.0 V @0.5s

  • Avg:

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

    \frac{1}{20}\ \ * \text{( 0.309017\ V + 0.587785\ V + 0.809017\ V + 0.951057\ V + 1.000000\ V + 0.951057\ V + 0.809017\ V + 0.587785\ V + 0.307017\ V + 0.000000\ V + ( - 0.309017\ V) + ( - 0.587785\ V) + ( - 0.809017\ V) + ( - 0.951057\ V) + ( - 1.000000\ V) + ( - 0.951057\ V) + ( - 0.809017\ V) + ( - 0.587785\ V) + ( - 0.309017\ V) + ( - 0.000000\ V)) = 0.000000\ V}

  • Slope:

    \text{Slope} = \ \frac{\text{Signallevel}_{\text{CursorB}} - \text{Signallevel}_{\text{CursorA}}}{\text{Delta}} = \frac{0.000000\ V - 0.309017\ V}{1.9\ s} = - 0.162640\ \frac{V}{s}

  • Min:

    The minimum value between cursor A and B is 0.0 V @1.0s and 2.0s

  • RMS:

    \sqrt{\{\frac{1}{20}}\sum_{1}^{20}

    {\lbrack(0.309017\ V)^{2} + (0.587785\ V)^{2} + ({0.809017\ V)}^{2} + (0.951057\ V)^{2} + (1.000000\ V)^{2} + (0.951057\ V)^{2} + (0.809017\ V)^{2} + ({0.587785\ V)}^{2} + (0.307017\ V)^{2} + {(0.000000\ V)}^{2} + ( - {0.309017\ V)}^{2} + ( - {0.587785\ V)}^{2} + ( - {0.809017\ V)}^{2} + ( - {0.951057\ V)}^{2} + ( - {1.000000\ V)}^{2} + ( - {0.951057\ V)}^{2} + ( - {0.809017\ V)}^{2} + ( - {0.5877852\ V)}^{2} + ( - {0.309017\ V)}^{2} + ( - {0.000000\ V)}^{2} \rbrack} = 0.707107 \text{\ V}

  • Frequ.:

    \text{Frequ}. = \ \frac{1}{\text{Delta}} = \frac{1}{1.9} = 526.3\ \text{mHz}

  • Integral:

    \text{Integral} = \ \text{Mean}*\text{Delta} = 0.000000\ V*1.9\ s = 0\ \text{Vs}

Note

Besides the Recorder Instrument, the cursor option is also available for the Chart Recorder and the Scope.

Quick expansion button

This button enlarges the Recorder to the full size of the measurement screen and reduces it to its original size. When the Recorder is set to the full size, all other instruments will move to the background.

Remark: Besides the Recorder, the Quick expansion button is also available for the Chart Recorder, the Scope, the FFT, the Video and the XY Plot.

Pinch/Scroll zoom feature

The zoom feature is a fundamental tool for the usage of the Recorder. It offers the user the possibility to scrutinize the data easily in real time.

  • Operating on a touch screen:

  • To perform this action with a touch screen, just do what you do with an everyday picture on your smart phone, pinch and zoom. Since the screen on a Trendcorder is so large, it is sometimes easier to use both hands to perform this action until you drill down into the finer data points.

    Zooming on a touch screen

    Fig. 314 Zooming on a touch screen

  • Operating with a mouse:

  • To zoom into the data with a mouse simply scroll upwards with the mouse’s scroll wheel or use the right mouse button in the following way:

Zooming with a mouse

Fig. 315 Zooming with a mouse

DejaView™

While recording data, the user is free to use the Recorder to view data from the past, even during long duration recording. This feature is called DejaView™. For activating this function, the user must click with the left mouse button in the recorder or touch the recorder with his finger and drag or swipe to the right. From this point the user is also free to pinch or scroll zoom into the data. To quickly get back to looking at the current data the user can simply press the grey >> symbol (see ② in Fig. 316) and they will be snapped back into time with the current incoming data. This is one of the most powerful features of the OXYGEN software.

Operational Features of DejaView™

Fig. 316 Operational Features of DejaView™

  • Operational features of DejaView™ (see Fig. 316)

  • ① Shows the part of the measurement file that is displayed in the recorder

  • ② After pressing this button, the recorder will jump to the actual position of the measurement file and show the latest recorded data

  • ③ A right click on this button makes the recorder show the recorded data from the recording start to the actual time position on the right end of the recorder

Note

The DejaView™ feature can be enabled and disabled in the System Settings menu point Advanced Setup (see Advanced setup).

Chart Recorder

Chart Recorder - overview

Fig. 317 Chart Recorder - overview

The Chart Recorder provides the user with the ability to view data together in one instrument as separate strip charts that are arranged one below the other. The Chart Recorder offers the same properties and analysis possibilities as the Recorder. For a detailed description refer to Recorder.

Note

Up to 16 channels can be assigned to one single Chart Recorder.

Bar Meter

Bar Meter - overview

Fig. 318 Bar Meter - overview

The Bar meter is an additional tool to show the user the measurement value of a channel. The following properties are available:

  • Range: Allows the user to define the range of the Bar meter. There is also the option to auto range the meter based upon the input channels range setting.

  • Limits: Allows users to color the Bar meter fill color based on different limit values. This helps in identifying signals which have hit a limit when the display is very “busy”.

  • Display Value: The meter shows either the actual channel value or the Average, RMS, ACRMS, Min, Max, Peak2Peak value at a user defined time interval of 0.1s, 0.25s, 0.5s, 1.0s.

  • Style: The user can specify the number of columns for a Bar meter cluster if several channels are selected.

    Selection of a transparent or untransparent background.

  • Layer: Moves the Instrument in front of or behind another object (only applicable in Design Mode).

Note

Up to 96 channels can be assigned to one single Bar Meter.

Indicator

Indicator – overview

Fig. 319 Indicator – overview

The Indicator can be used for a quick status overview feedback. Depending on the current channels’ value, the Indicator changes its color. The following Indicator properties can be configured:

  • Limits: The user can define a default color for the indicator as well as upper and lower limit values and colors

  • Display Value: Assigns the Indicators’ color to the actual channel value or to the Average, RMS, ACRMS, Min, Max, Peak2Peak channel value at a user defined rate in seconds

  • Style: The user can specify the number of columns for an Indicator cluster if several channels are selected

    Selection of a transparent or untransparent background.

  • Layer: Moves the Instrument in front of or behind another object (only applicable in Design Mode)

Note

Up to 96 channels can be assigned to one single Indicator.

Table instrument

Table Instrument - overview

Fig. 320 Table Instrument - overview

The Table provides the user the measurement data in table form with an individual column for each signal and a column for the Time Axis.

  • The Table instrument shows only statistics data if Show only statistics data is selected. The statistics data to be displayed can be selected from the dropdown above. Statistics Recording (see section 7) had to be enabled during recording for using this option

  • Style: Selection of a transparent or untransparent background.

Note

Up to 8 channels can be assigned to one single Table Instrument.

Image instrument

Image Instrument – overview

Fig. 321 Image Instrument – overview

This feature allows the user to add an image to the measurement screen, i.e. a picture of the device under test or the company logo. The data path can be selected via the Instrument Properties:

  • Source: Browse for the desired image file

  • Fill Mode: Select different modes to adjust the image file to the Instrument size

  • Style: Selection of a transparent or untransparent background.

  • Layer: Moves the Instrument in front of or behind another object (only applicable in Design Mode).

Note

An image file (.jpeg or .png can also be copied and pasted directly from the Windows Explorer into the OXYGEN measurement screen (see Fig. 322).

Pasting an image file to the measurement screen

Fig. 322 Pasting an image file to the measurement screen

Text instrument

Text instrument – overview

Fig. 323 Text instrument – overview

This feature allows the user to create customized text items on the measurement screen. Header data, time, data and the measurement time can also be displayed in the Text Box. For a detailed description how to display header data in the text box refer to Header data, for the other features see the next section. The following Instrument Properties are available:

  • Text: the desired text must be entered there. The entered text is automatically resized to fit within the boundaries of the text box. To change the color of the text, left click onto or touch the Color square to bring up the color selection palette. The style can be adjusted to Bold and Italic. Furthermore, the horizontal and vertical alignment can be changed.

  • Style: Selection of a transparent or untransparent background.

  • Layer: Moves the Instrument in front of or behind another object (only applicable in Design Mode).

Note

A text can also be copied and pasted directly to the OXYGEN measurement screen (see Fig. 324).

Pasting a text to the measurement screen

Fig. 324 Pasting a text to the measurement screen

Show Time, Date, Measurement Time

The Text instrument can also be used to show time, date or the elapsed time since measurement start (recording start) on the measurement screen. There are two possibilities available:

  1. The time and date display in the lower left corner can directly be dragged and dropped on the measurement screen (see ① in Fig. 323). A Textbox will be created automatically with the according time and date.

  2. In the instrument properties the time, date and measurement time can again dragged and dropped into the text field (see ② in Fig. 323).

Note

The text in front of the #-sign can be changedindividually.

Scope

Scope instrument – overview

Fig. 325 Scope instrument – overviewn

This instrument affords the user the analysis options of a scope.

Note

Up to 8 channels can be assigned to one single scope.

Instrument properties

  • Trigger settings:

  • In the Channel selection, the user can select the trigger channel. Any channel that is displayed on the scope can be selected.

  • In the Edge selection, the user can select if the selected signal shall be triggered on a Rising or on a Falling edge. The difference between the two modes is shown in Fig. 326 for a 1 Hz sine wave that has an amplitude of 1.

Trigger on a *Rising* (left) and on a *Falling* (right) edge

Fig. 326 Trigger on a Rising (left) and on a Falling (right) edge

  • In the Level selection, the user can define the level of the trigger. The level can also be set with the Level cursor (see Fig. 325) and must be within the signal range. Fig. 327 shows a 1 Hz sine wave with an amplitude of ±1 which is triggered with a rising edge on level 0 and level +0.5.

Rising trigger edge with level 0 (left) and level +0.5 (right)

Fig. 327 Rising trigger edge with level 0 (left) and level +0.5 (right)

In the Δ Hysteresis selection, the user can define a level the signal must pass before a new trigger event occurs. Setting a hysteresis level avoids unwanted trigger events that may occur caused by noise around the trigger level. The Δ Hysteresis level can also be set with the Hysteresis cursor (see Fig. 325).

  • If the signal is triggered on a Rising edge, the range of the Δ Hysteresis level can be set from [0 … (max_A + TL)].

  • If the signal is triggered on a Falling edge, the range of the Δ Hysteresis level can be set from [0 … (max_A – TL]].

Note

max_A: maximum signal Amplitude

TL: selected Trigger Level

  • Cursors: Select the desired values that shall show up when the cursors are activated. For a detailed description of the cursors refer to Activate cursors.

  • Time Axis Division: Change the scaling of the X-axis per division

  • Value Axis Division: Change the scaling of the displayed signals individually per division

  • Layer: Moves the Instrument in front of or behind another object (Only applicable in Design Mode)

  • Style:

    • Selection of a transparent or untransparent background.

    • Line Width selection from 1…10

  • The Offset Cursors (see Fig. 325) can be used to displace the displayed signals vertically. Using this function will not affect the phase accuracy.

Spectrum analyzer

Spectrum Analyzer - overview

Fig. 328 Spectrum Analyzer - overview

The FFT-Instrument provides the user with the ability to analyze data in real time within the frequency domain.

Assignment of Time Domain Channels

If analog channels that represent a time domain signal are assigned to the Instrument, the FFT is calculated according to the following formula:

Y_{k} = \sum_{n = 0}^{N - 1}{X_{n}e^{\frac{- i2\pi kn}{N}};\ \ \ \ \ \ k = 0\ldots N - 1}

Xk… (complex) input signal

Yk… complex Fourier Transform of Xk

N… number of samples

Depending on the spectrum to be plotted, the complex Fourier Transform Yk is used for further calculations. For continuative information, refer to Section Spectrum.

Note

  • Up to 8 channels can be assigned to one single Spectrum analyzer.

  • The Spectrum analyzer provides the zooming option as well. For the detailed description of the zooming function, refer to Pinch/Scroll zoom feature.

  • The user can easily export the currently displayed FFT-spectrum via pressing CTRL+C and paste it into an Excel file or Notepad window

  • Peak Hold function: To facilitate the read off from local maxima, the user can press the SHIFT key. This makes the cursor remain at local maxima.

Assignment of Frequency Domain Channels

Mathematical frequency channels that are calculated using the FFT math (see FFT channels) can be assigned and displayed to the Spectrum Analyzer as well. The Amplitude channel (called Channel_Name_Amp per default) and the Phase channel (called Channel_Name_Phi per default) can be assigned to the Spectrum Analyzer but no complex FFT channels (called Channel_Name_Cpx per default).

Note

  • Time domain channels and frequency domain channels cannot be assigned to the same Spectrum Analyzer but only to separate ones.

  • If frequency domain channels are assigned to the Spectrum Analyzer, the Instrument Properties are reduced to the Frequency axis and Value Axis settings (see Fig. 329). For details, refer to Additional instrument properties.

    Instrument Properties of the Spectrum Analyzer if Frequency Domain channels are assigned

    Fig. 329 Instrument Properties of the Spectrum Analyzer if Frequency Domain channels are assigned

Creating Reference Curves for the Spectrum Analyzer

The Spectrum Analyzer provides the possibility to create reference curves for threshold monitoring in the frequency domain.

An orange and a red colored reference curves can be created which will colorize the instruments’ background orange or re if the signal exceeds the reference curve.

The red reference curve has a higher priority than the orange one. This means that the instruments’ background will be colored red if the threshold of both reference curves will be exceeded. The colored background will be reset automatically when the threshold is decreased again.

To create a Reference curve, press the Edit.. button in the Reference Curve section of the Spectrum Analyzers’ Instrument Properties (see Fig. 330).

Instrument properties for Reference curves

Fig. 330 Instrument properties for Reference curves

A popup menu will open and the reference curve can be set up in table form (see Fig. 331). The + button can be used to add a value.

Table for reference curves definition

Fig. 331 Table for reference curves definition

The following Fig. 332 and Fig. 333 demonstrate the steps to create an orange and a red reference curve:

  1. Click on the Edit… button

  2. Press + to add one or more lines to the table

  3. Enter the frequency and the corresponding reference value to the table

  4. Press Close when finished and the curve will instantly be displayed

How to create an orange reference curve

Fig. 332 How to create an orange reference curve

How to create a red reference curve

Fig. 333 How to create a red reference curve

The Copy and Paste buttons can be used to copy and paste the table from the orange to the red curve and vice versa (see Fig. 334) or to export and import a value table into / to clipboard for interacting with Excel or other 3rd party software (see Fig. 335).

The X button (see Fig. 330) can be used to delete a reference curve again.

Copy and paste settings from one reference curve to another

Fig. 334 Copy and paste settings from one reference curve to another

Copy and paste values from/into Excel

Fig. 335 Copy and paste values from/into Excel

As soon as the table has been set up, the reference curve will be displayed in the Spectrum Analyzer (see Fig. 336, Fig. 337 and Fig. 338).

Reference curves without limit exceeded

Fig. 336 Reference curves without limit exceeded

Reference curves with orange limit exceeded

Fig. 337 Reference curves with orange limit exceeded

Reference curves with orange and red limit exceeded

Fig. 338 Reference curves with orange and red limit exceeded

Usage Of Harmonics Cursors

Harmonics Cursors can be displayed by checking Show Harmonics (see ① in Fig. 339). The number of harmonics can be set from 1 to 10 (see ② in Fig. 339). Harmonics are marked with cursors (see ③ in Fig. 339) and the harmonics amplitude is displayed at the instrument‘s bottom (see ④ in Fig. 339).

Usage of Harmonics Cursors

Fig. 339 Usage of Harmonics Cursors

The cursor position can be changed by entering a new frequency for the first harmonic (see ⑤ in Fig. 340). It is also possible to move the first harmonic cursor with the left mouse button (see ⑥ in Fig. 340). The position of the higher harmonics is automatically adjusted.

Changing the 1\ :sup:`st` Harmonics cursor position

Fig. 340 Changing the 1st Harmonics cursor position

Frequency Axis Settings

The unit of the X-axis is Hertz [Hz] per default (see ① in Fig. 341). The unit can be changed to Cycles Per Minute [CPM] which is defined as [Hz] * 60 (see ② in Fig. 341). The axis‘ minimum can be freely defined (see ③ and ④ in Fig. 341). The scaling can optionally bet set from linear to logarithmic scaling (see ⑤ in Fig. 341).

Frequency axis settings

Fig. 341 Frequency axis settings

Instrument Properties for Time Domain Channels

The desired Data size (i.e. the number of samples in time domain used for the calculation of one spectrum which is denoted with N in the upper formula) can be edited here. The data size is freely definable within a range from 42 to 1048576 (220) samples. The default settings are

1024 (210), 2048 (211), 4096 (212), 8192 (213), 16384 (214), 32768 (215), 65536 (216) 131072 (217) and 262144 (218) samples.

The Line resolution relates to the sample rate and the Data size:

Line\ Resolution = \ \frac{\text{Samplerate}}{\text{Window\ size}}\ \lbrack Hz\rbrack

The radio button Improve line resolution will enable zero-padding. For detailed information, refer to Improve Line Resolution (Enable zero-padding).

Note

  • If channels with different sample rates are displayed in one Spectrum analyzer:

  • The Line resolution is calculated for each sample rate individually and cannot be edited in the Instrument Properties. Thereby, the number of plotted FFT bins is the same for each signal but the FFT resolution is different.

  • Zero-padding (Improve line resolution) cannot be activated.

  • Note that changing the Data size will affect the Line resolution. Therefore, the line resolution is within a range from \frac{\text{Samplerate\ }}{2^{20}} to \frac{\text{Samplerate\ }}{42^{}} samples.

  • If Improve line resolution is de-selected, the number of calculated FFT bins is equal to the Data size. If Improve line resolution is selected, the number of calculated FFT bins is always higher than the number of data samples.

  • The number of plotted FFT bins is always trunc(\frac{\text{Number\ of\ calculated\ frequency\ bins\ }}{2}) + 1. The first line is plotted @ 0 Hz and the last line is plotted @ \frac{\text{Samplerate\ }}{2}Hz. If logarithmic frequency axis scaling is selected, the 0 Hz line will not be plotted, because the common logarithm is not defined for 0.

Section Window

The Type and Normalization of the window function can be edited here.

Window type

The Spectrum analyzer offers the usage of 7 different window functions (N denotes the Window size in samples and corresponds to the Data size):

  • Hanning window

    Hanning window in time and frequency domain (N = 128)

    Fig. 342 Hanning window in time and frequency domain (N = 128)

    w(n) = \ \frac{1}{2}\left\lbrack 1 - \cos\left( \frac{2\pi n}{N - 1} \right) \right\rbrack;\ \ \ \ \ \ n = 0\ldots N - 1

  • Hamming window

    Hamming window in time and frequency domain (N = 128)

    Fig. 343 Hamming window in time and frequency domain (N = 128)

    w(n) = \ \alpha - \beta\cos\left( \frac{2\pi n}{N - 1} \right);\ \ \ \ \ \ n = 0\ldots N - 1

    α = 0.54

    β… 1 – α

  • Rectangular window

    Rectangular window in time and frequency domain (N = 128)

    Fig. 344 Rectangular window in time and frequency domain (N = 128)

    `w(n) = \ 1\ ;\ \ \ \ \ \ n = 0\ldots N` -1

  • Blackman window

    Blackman window in time and frequency domain (N = 128)

    Fig. 345 Blackman window in time and frequency domain (N = 128)

    w(n) = \ a_{0} - a_{1}\cos\left( \frac{2\pi n}{N - 1} \right) + a_{2}\cos\left( \frac{4\pi n}{N - 1} \right);\ \ \ \ \ \ n = 0\ldots N - 1

    a0 = 0.42

    a1 = 0.5

    a3 = 0.08

  • Blackman-Harris window

    Blackman-Harris window in time and frequency domain (N = 128)

    Blackman-Harris window in time and frequency domain (N = 128)

    w(n) = \ a_{0} - a_{1}\cos\left( \frac{2\pi n}{N - 1} \right) + a_{2}\cos\left( \frac{4\pi n}{N - 1} \right) - a_{3}\cos\left( \frac{6\pi n}{N - 1} \right);\ \ \ \ \ \ n = 0\ldots N - 1

    a0 = 0.35875

    a1 = 0.48829

    a2 = 0.14128

    a3 = 0.01168

  • Flat-Top window

    Flat-Top window in time and frequency domain (N = 128)

    Flat-Top window in time and frequency domain (N = 128)

    w(n) = a_{0} - a_{1}\cos\left( \frac{2\pi n}{N - 1} \right) + a_{2}\cos\left( \frac{4\pi n}{N - 1} \right) - a_{3}\cos\left( \frac{6\pi n}{N - 1} \right) + a_{4}\cos\left( \frac{8\pi n}{N - 1} \right);n = 0\ldots N - 1

    a0 = 0.21557895

    a1 = 0.41663158

    a2 = 0.277263158

    a3 = 0.083578947

    a4 = 0.006947368

  • Bartlett window

    Bartlett window in time and frequency domain (N = 128)

    Bartlett window in time and frequency domain (N = 128)

    w(n) = 1 - \left| \frac{n - \frac{N - 1}{2}}{\frac{N - 1}{2}} \right|

The following table will give an overview and recommendations about the usage of the different window functions.

Note

This table is only a matter of recommendation and makes no claim to be complete or correct.

Table 36 Recommendation about the usage of different window functions (Source)

Signal Content

Window

Sine wave or combination of sine waves

Hanning

Sine wave (amplitude accuracy is important)

Flat Top

Narrow-band random signal (vibration data)

Hanning

Broadband random (white noise)

Rectangular

Closely spaced sine waves

Rectangular, Hamming

Unknown Content

Hanning

Accurate single tone amplitude measurements

Flat Top

The following figure compares the different window functions in time domain:

Comparison of the window functions in time domain (N = 128)

Fig. 346 Comparison of the window functions in time domain (N = 128)

The following table summarizes the two most important characteristics of the different window functions. The Main Maximum Width describes the single-sided width of the main maximum as number of FFT bins. The Main Maximum Width in Hz is the product of Main Maximum Width and Line resolution. The Max. Side Lobe Level denotes the damping of the first side lobe compared to the main maximum in decibel.

Table 37 Properties of the window functions

Window function

Main Maximum Width

Max. Side Lobe Level [dB]

Hanning

2

-31

Hamming

2

-43

Rectangular

1

-13

Blackman

3

-58

Blackman-Harris

4

-92

Flat-Top

5

-68

Bartlett

2

-27

Normalization

As the usage of a window function causes a decrement of the signals’ amplitude and power, the user can select between None, Amplitude True and Power True Normalization.

  • None: The spectrum will not be normalized, and the amplitude and the power error will remain

  • Amplitude True: The damping of the signal amplitude caused by the window function will be compensated. The power loss will remain. The correction happens according to the following formula:

    S_{\text{AmpCorr}\ k} = S_{k}*\left\lbrack \frac{N}{\sum_{k = 1}^{N}W_{k}} \right\rbrack

  • Power True: The Power loss caused by the multiplication with the window function will be compensated and the amplitude error will remain. The correction happens according to the following formula:

    S_{\text{PowCorr}\ k} = S_{k}*\sqrt{\frac{N}{\sum_{k = 1}^{N}W_{k}^{2}}}

    Sk… Un-normalized signal at position k

    N… Length of the Window function

    Wk…Value of the window function at position k

  • A detailed example for the necessity to normalize FFT spectra can be found in Normalization of FFT Spectra.

Note

The normalization is applied to the signal in time domain.

Section Spectrum

In the Spectrum section, the user can select the type of the spectrum plotted in the Spectrum analyzer. In the following section, the available spectra and their formula are listed.

  • Amplitude: Plots the default amplitude spectrum normalized to the number of FFT lines 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{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{Unit}\rbrack

  • Amplitude RMS: Plots the RMS amplitude spectrum by dividing the Amplitude spectrum by .

    A_{\text{RMS}\ k} = \frac{A_{k}}{\sqrt{2}};\ \ \ \ \ \ \ k = 1\ldots N\ \ \ \ \ \lbrack\text{Unit}\rbrack

  • Amplitude²: Plots the squared amplitude spectrum by squaring the Amplitude spectrum

    A_{\text{sq}\ k} = A_{k}^{2};\ \ \ \ \ \ \ k = 1\ldots N\ \ \ \ \ \lbrack(\text{Unit})²\rbrack

  • Decibel: Plots the logarithmic Amplitude spectrum referred to a freely definable reference level ARef. The reference value Aref can be edited in the Value section and its corresponding level can be defined in the Level section.

    L_{A\ k} = 20*\log_{10}{\left( \frac{A_{k}}{A_{\text{Ref}}} \right);\ \ \ \ \ \ \ k = 1\ldots N}\ \ \ \ \ \lbrack\text{dB}\rbrack

  • Decibel RMS: Plots the logarithmic Amplitude RMS spectrum referred to a freely definable reference level ARef. The reference value Aref can be edited in the Value section and its corresponding level can be defined in the Level section.

    L_{A\ \text{RMS}\ k} = 20*\log_{10}{\left( \frac{A_{\text{RMS}\ k}}{A_{\text{Ref}}} \right);\ \ \ \ \ \ \ k = 1\ldots N}\ \ \ \ \ \lbrack\text{dB}\rbrack

  • Decibel Max Peak: Plots the logarithmic Amplitude spectrum referred to the highest occurring value in the Amplitude spectrum. Thus, the highest occurring value corresponds to 0 dB.

    L_{A\ \text{Max}\ k} = 20*\log_{10}{\left( \frac{A_{k}}{{\max\{ A}_{k}\}} \right);\ \ \ \ \ \ \ k = 1\ldots N}\ \ \ \ \ \lbrack\text{dB}\rbrack

  • Decibel V-RMS: Plots the logarithmic Amplitude spectrum referred to 1 [Signal Unit] (1 V (RMS) is a common reference level for voltage and corresponds to 0 dBV)

    L_{A\ \text{Max}\ k} = 20*\log_{10}{\left( \frac{A_{\text{RMS}}}{1} \right);\ \ \ \ \ \ \ k = 1\ldots N}\ \ \ \ \ \lbrack\text{dB}\rbrack

  • Decibel u-RMS: Plots the logarithmic Amplitude spectrum referred to \sqrt{0.6} [Signal Unit] ( \sqrt{0.6} = 0.775V (RMS) is a common reference level for voltage and corresponds to 0 dBu. 0.775V is the voltage that converts 1 mW electrical power on a 600 Ω resistance)

    L_{A\ \text{Max}\ k} = 20*\log_{10}{\left( \frac{A_{\text{RMS}}}{\sqrt{0.6}} \right);\ \ \ \ \ \ \ k = 1\ldots N}\ \ \ \ \ \lbrack\text{dB}\rbrack

  • Sound Pressure Level: Plots the logarithmic Amplitude spectrum referred to 20µ [Signal Unit] (20 µPa is the common reference level for sound pressure in air and corresponds to 0 dB)

    L_{A\ \text{Max}\ k} = 20*\log_{10}{\left( \frac{A_{\ \text{RMS}}}{20µ} \right);\ \ \ \ \ \ \ k = 1\ldots N}\ \ \ \ \ \lbrack\text{dB}\rbrack

  • Sound Pressure Level (Water): Plots the logarithmic Amplitude spectrum referred to 1µ [Signal Unit] (1 µPa is the common reference level for sound pressure in water and corresponds to 0 dB)

    L_{A\ \text{Max}\ k} = 20*\log_{10}{\left( \frac{A_{\ \text{RMS}}}{1µ} \right);\ \ \ \ \ \ \ k = 1\ldots N}\ \ \ \ \ \lbrack\text{dB}\rbrack

  • PSD: The Power Spectral Density (PSD) is based on the magnitude squared spectrum (Msq) which differs from the amplitude squared spectrum (Asq) insofar that the magnitude squared spectrum is only a one-sided spectrum.

    M_{\text{sq}\ k} = \text{Re}\left\{ Y_{k} \right\}^{2} + \text{Im}\left\{ Y_{k} \right\}^{2};\ \ \ \ \ \ \ k = 1\ldots N\ \ \ \ \ \ \lbrack(\text{Unit})²\rbrack

    \text{PSD}_{k} = \frac{1}{N^{2}}*\frac{1}{\text{df}}*M_{\text{sq}\ k};\ \ \ \ \ \ \ \text{with}\ \text{df} = \ \frac{\text{Samplerate}}{N}\ \ \ \ \ \ \lbrack\left( \text{Unit} \right)^{2}/\text{Hz}\rbrack

  • PSD-TISA: plots the Time Integrated Squared Amplitude (TISA) PSD

    {PSD - TISA}_{k} = \frac{1}{N}*\text{dt}*M_{\text{sq}\ k};\ \ \ \ \ \ \ k = 1\ldots N,\ \ \ \ \text{dt} = \ \frac{1}{\text{Samplerate}}\ \ \ \ \ \ \lbrack\left( \text{Unit} \right)^{2}s\rbrack

  • PSD-MSA: plots the Mean Squared Amplitude (MSA) PSD

    {PSD - MSA}_{k} = \frac{1}{N^{2}}*M_{\text{sq}\ k};\ \ \ \ \ \ \ k = 1\ldots N\text{\ \ \ \ \ \ }\left\lbrack \left( \text{Unit} \right)^{2} \right\rbrack

  • PSD-SSA: plots the Sum Squared Amplitude (SSA) PSD

    {PSD - SSA}_{k} = \frac{1}{N}*M_{\text{sq}\ k};\ \ \ \ \ \ \ k = 1\ldots N\ \ \ \ \ \ \lbrack\left( \text{Unit} \right)^{2}\rbrack

Note

PSD, PSD-TISA, PSD-MSA and PSD-SSA are different scalings of the same spectral content and differ in the physical unit.

  • Phase: Plots the phase spectrum from -180° … +180°.

    \varphi_{\ k} = \tan^{- 1}\frac{Im\{ Y_{k}\}}{Re\{ Y_{k}\}};\ \ \ \ \ \ \ k = 1\ldots N\ \ \ \ \ \lbrack{^\circ}\rbrack

  • Phase unwrapped: Plots the unwrapped phase spectrum to avoid discontinuities from -900° … +900°.

    \varphi_{\ k,unwrapped} = \tan^{- 1}\frac{Im\{ Y_{k}\}}{Re\{ Y_{k}\}};\ \ \ \ \ \ \ k = 1\ldots N\ \ \ \ \ \lbrack{^\circ}\rbrack

  • Phase radiant: Plots the phase spectrum from - … +.

    \varphi_{k} = \frac{\varphi_{k}}{360{^\circ}}2\pi;\ \ \ \ \ \ \ k = 1\ldots N\ \ \ \ \ \lbrack rad\rbrack

  • Phase unwrapped (radiant): Plots the unwrapped phase spectrum to avoid discontinuities from – … +..

    \varphi_{\ k,\ unwrapped} = \frac{\varphi_{\ k,unwrapped}}{360{^\circ}}2\pi;\ \ \ \ \ \ \ k = 1\ldots N\ \ \ \ \ \lbrack rad\rbrack

Section Periodogram

The usage of a window function damps the signal information at the window edges and emphasizes the signal information in the middle of the window function. If the signal is stationary, the variance of its spectrum rises. This problem can be avoided with a periodogram. If the option Periodogram is selected, the spectrum is calculated for overlapping signal parts and averaged afterwards. This procedure reduces the variance, but the spectral resolution is degraded as well.

  • In the Average selection, the user can select the number of spectra that shall be used for the mean value calculation. 2, 3, 4, 5, 8 or 10 spectra can be used for the mean value calculation.

  • In the Overlap selection, the user can select how much the single spectra used for the mean value calculation shall overlap in the time domain. The user can select an overlapping factor of 0 %, 50 %, 75 % 80 % or 90 %.

  • The Periodogram calculation is exemplified in Calculation of a Periodogram.

Additional instrument properties

  • Frequency Axis: Change the scaling of the X-axis

  • Value Axis: Change the scaling of the Y-axis. For quick Y-axis scaling features, refer to Quick selection Y-axis scaling.

  • Style:

    • Selection of a transparent or untransparent background.

    • Line Width selection from 1…10

  • Layer: Moves the Instrument in front of or behind another object

Note

The properties of the FFT can be changed and updated in the PLAY mode as well as in the LIVE and REC mode.

Markers

FFT Marker - Overview

Fig. 347 FFT Marker - Overview

To analyze the behavior of a certain frequency line, the user can display the actual value in a table below the FFT plot. Therefore, the user must select the desired frequency line with a mouse click. Then, the selected point will show up in the table. The user can change the frequency position by moving the respective cursor across the frequency axis or with a double click on the frequency in the table. Up to five frequency lines can be displayed in the table simultaneously. While moving the mouse in the frequency plot, the actual frequency and the actual signal value of the signal next to the cursor are displayed in the upper left corner.

Improve Line Resolution (Enable zero-padding)

If Improve Line Resolution is selected, zero-padding is enabled. The following paragraph explains the idea of zero-padding and its properties.

Theory of zero-padding

If zero-padding is not applied, the line resolution and thus the accuracy of a FFT depends on the length of the transformed signal and on the sample rate:

Line\ Resolution = \ \frac{\text{Samplerate}}{\text{Window\ size}}\ \lbrack Hz\rbrack

The data size is equal to the number of FFT bins here. Thus, a higher line resolution can be achieved by reducing the sample rate or increasing the data size. Normally, a sample rate reduction cannot be accepted due to bandwidth reasons. Increasing the data size may cause problems in Realtime applications, because the delay until an FFT is displayed increases with increasing data size. Moreover, if short signals are transformed, a data size increment is simply not possible.

Zero-padding adds zeros at the end of the signal part to be transformed and thus increases the data size artificially. Please note that the Data size is not any more equal to the number of FFT bins. The following example will clarify that: A 64-sample signal in time domain shall be matched to an FFT with 256 FFT bins. Therefore, 192 zeros must be added at the end of the 64-sample signal in time domain. Thus, the Line resolution can be determined according to the following formula:

Line\ Resolution = \ \frac{\text{Samplerate}}{Window\ size + Number\ of\ zeros} = \frac{\text{Samplerate}}{\text{Number\ of\ frequency\ lines}}\ \lbrack Hz\rbrack

In OXYGEN, the number of attached zeros can be manipulated indirectly by varying the Data size or the Line resolution in the Instrument Properties of the Spectrum analyzer (see Instrument Properties for Time Domain Channels).

In OXYGEN, the Line resolution can be selected from \frac{\text{Samplerate}}{2^{20}} to \frac{\text{Samplerate}}{\text{Window}\ \text{size}} if zero-padding is selected. If a lower line density is desired, zero-padding is not required and can be de-selected.

In the signal theory, the two most common application areas of zero-padding are the already explained increased sample density in the frequency domain and the signal enlargement to a length of 2n samples, because time signals with a length of 2n samples permit a faster FFT-computation.

Even though zero-padding increases the sample density in the frequency domain, the FFT is not more accurate if zero-padding is used. Zero-padding is only a kind of an interpolation and does not increase the resolution. This characteristic is shown in Zero-padding – A practical example. To increase the resolution, a longer signal in time domain is required.

Note

Zero-padding is applied after multiplying the signal with the window function.

Zero-padding – A practical example

In this section, zero-padding is explained with an easy practical example. For this purpose, the following signal is used:

Signal 1 in time domain, 2s (41 samples)

Fig. 348 Signal 1 in time domain, 2s (41 samples)

x(t) = \ 2.5*sin(2*\pi*1*t)

The signal has a length of 2 seconds and is sampled with 20 Hz. Thus, the signal consists of 41 samples. Transforming the signal into the frequency domain leads to the following spectrum:

Signal 1 in frequency domain, no zero-padding

Fig. 349 Signal 1 in frequency domain, no zero-padding

The spectrum consists of 41 bins and the peaks @1 Hz and 19 Hz are clearly visible.

Now, the signal length is enhanced from 41 samples to 64 samples by adding 23 samples at the end of the signal:

Signal 1 in time domain, zero-padding to 64 samples

Fig. 350 Signal 1 in time domain, zero-padding to 64 samples

Transforming the signal to the frequency domain leads to the following spectrum:

Signal 1 in frequency domain, zero-padding to 64 samples

Fig. 351 Signal 1 in frequency domain, zero-padding to 64 samples

Now the spectrum consists of 64 samples and not 41 samples and the additional frequency bins are kind of an interpolation but do not lead to a sharper spectrum.

The same trend is visible if the original signal is enhanced from 41 samples to 128 samples by adding 87 zeros at the end of the signal:

Signal 1 in time domain, zero-padding to 128 samples

Fig. 352 Signal 1 in time domain, zero-padding to 128 samples

This signal leads to the following spectrum with 128 frequency bins:

Signal 1 in frequency domain, zero-padding to 128 samples

Fig. 353 Signal 1 in frequency domain, zero-padding to 128 samples

Again, the additional bins are only kind of an interpolation, but do not lead to a sharper spectrum.

To enlarge the accuracy of the FFT, a longer signal in time domain is required. Therefore, the original sine signal is enlarged to 6.4 seconds (128 samples):

Signal 2 in time domain, 6.4s (128 samples)

Fig. 354 Signal 2 in time domain, 6.4s (128 samples)

The resulting spectrum consists also of 128 bins but now, the additional bins really lead to a sharper spectrum and are no longer only an interpolation of the original 41 frequency bins:

Signal 2 in frequency domain, no zero-padding

Fig. 355 Signal 2 in frequency domain, no zero-padding

Normalization of FFT Spectra

In this section, the necessity of the normalization during the FFT calculations is explained. Therefore a 50 Hz sine wave with 2.5 amplitude shall be transformed to the frequency domain. The sample rate is 1000 Hz and the signal length 10s. The signal looks as follows in time domain:

Signal in time domain (first 250 ms)

Fig. 356 Signal in time domain (first 250 ms)

x(t) = \ 2.5*sin(2*\pi*50*t)

After transforming the signal into the frequency domain according to the formula

Y_{k} = \sum_{n = 0}^{N - 1}{X_{k}e^{\frac{- i2\pi kn}{N}};\ \ \ \ \ \ k = 0\ldots N - 1}\ \ \ \ \ \ \ \ \ \ (N = 10001)

and determining the absolute value, the spectrum is the following:

x(t) in frequency domain

Fig. 357 x(t) in frequency domain

Two things are peculiar:

  • As the FFT produces a two-sided spectrum, there is a bin @ 50 Hz and @ 950 Hz.

  • As the signal level of the two peaks is ~12500, the unit seems to be arbitrary.

  • To create a comprehensible signal unit, the Fourier Transform of the signal must be divided by the length of the FFT which is 10001 in this example.

Y_{\text{nor}m_{k}} = \frac{Y_{k}}{N};\ \ \ \ \ \ k = 0\ldots N - 1\ \ \ \ \ (N = 10001)

x(t) in frequency domain divided by the FFT-length

Fig. 358 x(t) in frequency domain divided by the FFT-length

Now, the amplitude of both peaks is ~1.25. As we still have two peaks whose sum is ~2.5, the signal unit issue is solved by dividing the spectrum by the length of the FFT.

In a next step, we truncate the spectrum at the Nyquist frequency (\left( \frac{f_{s}}{2} \right)) which is 500 Hz in our case and multiply the remaining spectrum from 0 to 500 Hz with the factor 2 to ensure that the power of the signal in the frequency domain is still the same as in the time domain. After that, the following spectrum results:

One-sided spectrum X(f) multiplied by factor 2

Fig. 359 One-sided spectrum X(f) multiplied by factor 2

In this first example, there is no normalization needed, because we didn’t use a window function. In this case, there was no window function needed, because we transformed a finite and periodical signal. In practice, this is normally not the case and a continuing signal is transformed block by block. As these block lengths are finite, the Leakage effect occurs if the block length does not coincidentally match with an integer multiple of the signal period. In this case, the frequency spectrum becomes too wide. This is a natural effect resulting from the Fourier Transform property which says that a multiplication in time domain leads to a convolution in the frequency domain. The fact that the frequency spectrum becomes too wide can be optimized but not completely rejected by the usage of a window function. This leads to the fact that the signal is faded in at the beginning of the window and faded out at the end of the window. Thus, an artificial periodical signal results and an error in the signal amplitude results. This amplitude error is corrected by the normalization of the signal.

Let’s assume again the 50 Hz sine wave with 2.5 amplitude shown in Fig. 356 and multiply it with a Hanning window. The formula for the creation of a Hanning window can be found in section Window type. After the multiplication, the signal looks as follows:

x(t)\ :sub:`win` in time domain; multiplied with a Hanning window

Fig. 360 x(t)win in time domain; multiplied with a Hanning window

x(t)_{\text{win}} = \left\lbrack 2.5*sin(2*\pi*50*t) \right\rbrack*\left\lbrack 0.5*\left( 1 - \cos\left( \frac{2*\pi*n}{N - 1} \right) \right) \right\rbrack;\ \ \ \ \ n = 0\ldots N - 1

The spectrum of the signal looks as follows:

x(t)\ :sub:`win` in frequency domain

Fig. 361 x(t)win in frequency domain

Again, the signal unit looks arbitrary. Thus, we divide the spectrum by the length of the FFT (N=10001) again.

x(t)\ :sub:`win` in frequency domain divided by the FFT-length

Fig. 362 x(t)win in frequency domain divided by the FFT-length

After that we truncate the signal again at the Nyquist frequency and multiply the remaining spectrum with the factor 2 to secure that the signal power in time and frequency domain is equal.

One-sided spectrum X(f)\ :sub:`win` multiplied by factor 2

Fig. 363 One-sided spectrum X(f)win multiplied by factor 2

Now we clearly see that the peak @50 Hz is not 2.5 as before but only ~1.25. This is because of the windowing. This can be corrected with the normalization. There are two possibilities: We can either normalize the spectrum to the original signal amplitude or to the original signal power.

To refit the spectrum according to the original signal amplitude, we must select the Amplitude True normalization:

{X(f)_{\text{win}}}_{\text{AmpCorr}} = {X(f)}_{\text{win}}*\lbrack\frac{N}{\sum_{k = 1}^{N}W_{k}}\rbrack

where N denotes again the window (and signal) length and Wk the value of the window function at position k.

Amplitude-True-normalized spectrum X(f)

Fig. 364 Amplitude-True-normalized spectrum X(f)

There we can see that the peak @50 Hz is again 2.5. But in this case, the signal power in frequency domain is not the same as in time domain. If this is required, we must select the Power True normalization:

{X(f)_{\text{win}}}_{\text{PowCorr}} = X(f)_{\text{win}}*\sqrt{\frac{N}{\sum_{k = 1}^{N}W_{k}^{2}}}

where N denotes again the window (and signal) length and Wk the value of the window function at position k.

Power-True-normalized spectrum X(f)

Fig. 365 Power-True-normalized spectrum X(f)

Now, the power in frequency domain is the same as in time domain, but the amplitude does not match correctly anymore.

Calculation of a Periodogram

This section will demonstrate the calculation of a periodogram on a practical example. The exemplary window size is 1000 samples. The following figures illustrate the decomposition of a time signal for the calculation of a periodogram:

Decomposition of the time signal for a Periodogram with an average of 4 spectra and 0 % overlapping

Fig. 366 Decomposition of the time signal for a Periodogram with an average of 4 spectra and 0 % overlapping

Decomposition of the time signal for a Periodogram with an average of 4 spectra and 75 % overlapping

Fig. 367 Decomposition of the time signal for a Periodogram with an average of 4 spectra and 75 % overlapping

Decomposition of the time signal for a Periodogram with an average of 2 spectra and 50 % overlapping

Fig. 368 Decomposition of the time signal for a Periodogram with an average of 2 spectra and 50 % overlapping

Video Instrument

Video instrument – overview

Fig. 369 Video instrument – overview

OXYGEN provides the possibility to record a video during the measurement with a webcam or with a DEWE-CAM-GIGE-120/-50-HD. For example, this is a very useful tool for automotive applications when a test run is performed, and the test track shall be recorded. Please note that the camera channels are not activated by default in a new setup. This can be changed in the Data Channels menu in the Video Channels section by clicking on the Activate switch. This will activate your plugged camera. For enabling the record mode as well, make sure that the Stored button has the red colored background (see Fig. 370).

Activate cameras and enable recording

Fig. 370 Activate cameras and enable recording

After that the user can find the cameras in the Data Channel List of the Video Instrument and assign a video channel.

Note

The video recording with a webcam or a DEWE-CAM-GigE-120/-50-HD in fixed frame rate mode are not synchronized to the other measurement channels. When synchronized recording is required, OXYGEN supports time synchronous recording with a DEWE-CAM-GigE-120/-50-HD.

For the driver installation and the required software settings refer to the Installation Guide of the DEWE-CAM-GigE in OXYGEN.

Note

If the camera channel does not appear in the Channel List although a camera is connected to the measurement system, make sure that CAMERA Series for webcams or the GIGECAMERA Series for GigE cameras are enabled in the DAQ Hardware setup (see Fig. 371) in the System Settings.

Enabling the Camera Series and the GigE Camera series in the DAQ Hardware setup

Fig. 371 Enabling the Camera Series and the GigE Camera series in the DAQ Hardware setup

The Video Instrument has the following Instrument Properties (see Fig. 369):

  • Style: The user can specify the number of columns if several channels are selected. Selection of a transparent or untransparent background.

  • Video Display: If Show time is selected, the current measurement time is displayed in the Video Instrument

  • Layer: Moves the Instrument in front of or behind another object (only applicable in Design Mode).

Note

For each connected camera, there exists a counter channel that counts the number of received frames since acquisition start. The channel has the same name as the respective camera with RcvdCNT appended. To activate the counter, you need to activate the channel (The channel is not activated automatically). The channel can be found in the Video Channels section of the Channel List (see Fig. 372).

Frame Counter Channel

Fig. 372 Frame Counter Channel

Note

When using more than one USB camera, problems may occur under Windows 10® if they are connected on the same USB hub. The second camera (and others) may not work/show a picture. If more cameras shall be used, only one camera per USB hub should be connected to the system.

XY plot

XY plot instrument – overview

Fig. 373 XY plot instrument – overview

With the XY plot, it is possible to analyze the dependency of a measurement channel on the Y-axis to another one on the X-axis. A common application in the automotive sector is the analysis of the engine’s sound pressure level (Y-axis) in the dependency of the motor speed (X-axis). The user can manipulate the following instrument properties:

  • XYPLOT

    The user can select the channel that shall be plotted on the X-axis in the X Axis Channel drop-down menu. The other selected channels will be plotted on the Y-axis. With the menus Draw points, Draw lines and their size selection the user can change the graphical characteristics of the plotted signal.

  • Interval

    The time interval of the plotted data is displayed here and in the upper left corner of the Instrument. To start the drawing of a new plot and delete the currently displayed time interval the user can press the Clear button. If the check box Limit duration is selected the user can define a time interval to limit the plotted information, i.e. when 1 second is selected, all information older than 1 second will be deleted automatically.

  • Y-axis:

    • Individual scaling creates a separate Y-axis for each signal

    • Automatic scaling zooms the Y-axis to the actual displayed min and max value

  • Range: Assign a user-defined min/max value to the Y-axis scaling

  • X-axis:

    • Automatic scaling zooms the X-axis to the actual displayed min and max value

  • Range: Assign a user-defined min/max value to the X-axis scaling.

  • Style: Selection of a transparent or untransparent background.

  • Layer: Moves the Instrument in front of or behind another object (only applicable in Design Mode)

Note

  • Additional features for Y-axis scaling (see Quick selection Y-axis scaling) and zooming (see Pinch/Scroll zoom feature) are also supported in the XY-Plot Instrument

  • In the PLAY mode and LIVE mode (with frozen screen) the user can scroll through the measurement data by moving the orange time marker in the Overview bar (see Fig. 374) or in a Recorder if one is displayed. The Interval settings in the Instrument Properties are respected during this operation.

  • Up to 9 channels can be assigned to one single Table Instrument (1 channel to the X-axis, 8 channels to the Y-axis).

XY-Plot - Data scrolling

Fig. 374 XY-Plot - Data scrolling

GPS plot

GPS plot instrument – overview

Fig. 375 GPS plot instrument – overview

With the GPS plot, the user can display the GPS-channels Latitude, Longitude and Heading which are acquired by a TRION-TIMING or TRION-VGPS-20/-100 module (see GPS channels). The individual channels Latitude, Longitude and Heading are matched automatically to the LAT, LON and HEAD input parameter of the Instrument according to the Channel Mode. Thus, the channels can be renamed arbitrarily.

Instead of the raw hardware channels Latitude, Longitude and Heading, mathematical channels can be assigned to the GPS plot as well (i.e. Statistics channels of Longitude, Latitude or Heading). If mathematical channels shall be assigned to the GPS plot, the corresponding Latitude channel must be assigned first, the Longitude channel second and the Heading channel third. In this case, an automatic channel match is not possible, because the Channel Mode information is missing.

The assignment of the individual channel to the LAT, LON and HEAD input parameter of the Instrument can be seen in the upper left corner of the Instrument.

The displayed map is an online map from OpenStreetMap©. If the PC has no internet connection, the map is displayed if it is stored in the cache. If the cache is empty, no map is displayed without internet connection.

The user can manipulate the following Instrument Properties:

  • ZOOM MODE

    • Manual: The user can zoom with the scroll wheel and move the map with the left mouse button. The actual position will not be centered when the position is updated.

    • Fit: The complete track of the object is visible in the Instrument. Zooming or moving is not applicable.

    • Center: The actual position of the tracked object is always displayed in the center of the Instrument. Zooming with the scroll wheel and moving with the left mouse button is possible but the actual position will be centered again when the position is updated.

    • Rotate: The actual position of the tracked object is always displayed in the center of the Instrument and the heading shows always to the top. Zooming with the scroll wheel and moving with the left mouse button is possible but the actual position will be centered again when the position is updated.

  • Show Map: The user can select if the map shall be displayed or not

  • TRACK

    The elapsed track will be deleted by clicking on the Clear button. The drawing of the elapsed track can be limited by entering a time in seconds in at Limit duration

    • Style: Selection of a transparent or untransparent background.

    • Layer: Moves the Instrument in front of or behind another object (only applicable in Design Mode).

  • BACKGROUND IMAGE

    For offline usage, an image can be loaded to replace the map. An image can be selected by clicking on the Import Image button and browsing for the desired file. After selecting the desired file, the Positioning dialog will open:

    Image positioning dialog

    Fig. 376 Image positioning dialog

Two GPS coordinates within the loaded image must be known to position the image correctly. In Fig. 376, the two points and their corresponding coordinates are marked with red and blue. The procedure to position the image is the following:

  • Two red cursors are generated by the Positioning dialog. In Fig. 376, they can be found at the top of the image. These cursors must be put on the known coordinates.

  • The coordinates of both known points must be entered.

  • Latitude and Longitude of MAP POINT 1 must be entered for the known coordinates the first red cursor is placed on. In Fig. 376, this is the GPS coordinate marked with blue

  • Latitude and Longitude of MAP POINT 2 must be entered for the known coordinates the second red cursor is placed on. In Fig. 376, this is the GPS coordinate marked with red

  • Alternatively, the image pixel corresponding to MAP POINT 1 and MAP POINT 2 can be entered in the X and Y columns

  • After the positioning is finished and clicking on Apply, the image is placed correctly on the map (see Fig. 377):

    Positioned image

    Fig. 377 Positioned image

  • The positioning can be edited by clicking on Position image and removed by clicking on the X button (see Fig. 378):

    Editing the loaded image

    Fig. 378 Editing the loaded image

GPS quality

GPS Quality instrument - overview

Fig. 379 GPS Quality instrument - overview

The GPS quality instrument displays the number of visible and used satellites of GPS data which is acquired by a TRION-TIMING or TRION-VGPS-20/-100 module (see GPS channels) and further meta data. The used satellites are thereby the satellites with the best SNR. The NMEA data channel can be assigned to the GPS quality instrument. Normally, the NMEA data channel is called GPS 1/1 per default and can be found on the top of the GPS data channels list:

GPS NMEA data channel

Fig. 380 GPS NMEA data channel

Besides the satellites plot, the following meta data which is contained in the NMEA string can be displayed in the GPS quality instrument:

  • Latitude

  • Longitude

  • Altitude

  • Velocity

  • Heading

  • Satellite used

  • Satellites in view

  • Quality

  • Dilution

The following Fig. 381 explains the meaning of the three black circles with the same center point in the satellites plot:

Explanation of the satellites plot

Fig. 381 Explanation of the satellites plot

The deselection of the instrument property Extended View reduces the content of the GPS plot Instrument to the satellites plot:

GPS quality instrument - *Extended View* selected

Fig. 382 GPS quality instrument - Extended View selected

GPS quality instrument - *Extended View* deselected

Fig. 383 GPS quality instrument - Extended View deselected

Spectrogram

Spectrogram instrument – overview

Fig. 384 Spectrogram instrument – overview

The Spectrogram may be used to display the time dependent signal trend of a FFT amplitude or phase channel that was created with the FFT math (for details, refer to FFT channels).

The elapsed time is displayed on the X-axis, the frequency on the Y-axis and the amplitude of the signal is Color-Coded to the Z-Axis (Left instrument in Fig. 384).

Note

Only 1 FFT amplitude or phase channel can be assigned to one single Spectrogram.

The Spectrogram has the following Instrument Properties:

  • Time Axis – Orientation: Horizontal orientation assigns the time axis to the X-axis of the instrument (see left instrument in Fig. 384) and Vertical orientation assigns the time axis to the Y-axis of the instrument (see right instrument in Fig. 384).

  • Time Axis - Format: This property changes the format of the X-axis. The user can select between Auto, Absolute time and Relative time.

    • Auto: In Sync Mode, the Auto time format is the Absolute time, otherwise the Auto time format is the Relative time.

    • Absolute time: The unit of the X-axis is the actual time of day set in the OS settings.

    • Relative time: The unit of the X-axis is the relative time starting with 0:00 for every new measurement.

  • Time Axis – Duration: Select the Time interval that shall be plotted on the Time Axis here. The Clear button deletes the actual displayed data from the instrument.

  • Frequency Axis: Select the upper and lower frequency the of the plotted data here.

  • Gradient: Select a color scheme here. The color intensity can either be changed by entering the value in this menu or by moving the color bar within the instrument up or down while keeping the left mouse button pressed.

  • Style: Selection of a transparent or untransparent background.

  • Layer: Moves the Instrument in front of or behind another object (only applicable in Design Mode)

Power Group

Power Group instrument – overview

Fig. 385 Power Group instrument – overview

OXYGEN Power is the up to date Power Analyzer software add-on for DEWETRON OXYGEN Measurement Software. For a detailed explanation of the functionality and usage of the Power module, refer to the manual DEWETRON_OXYGEN_Power_Technical_Reference_Rx.x.

Intensity Diagram

Intensity Diagram instrument - overview

Fig. 386 Intensity Diagram instrument - overview

The Intensity Diagram can be used to display the frequency and order matrix of an order analysis channel or the resulting matrix of a matrix sampler channel, i.e. an efficiency map.

The Intensity Diagram has the following Instrument Properties:

  • Orientation: Horizontal orientation assigns the defined X channel to the X-axis of the instrument and Vertical orientation assigns the defined X channel to the Y-axis of the instrument.

  • Min/Max: the minimum and maximum value can be entered to be displayed in the instrument.

  • Gradient: Select a color scheme here. The color intensity can either be changed by entering the value in this menu or by moving the color bar within the instrument up or down while keeping the left mouse button pressed.

  • Select levels to have a more defined grading in the matrix. Select the number of levels which should be defined with a black border. The matrix on the left in Fig. 386 shows no grading and the matrix on the right has a 10-level grading.

  • Enter the minimum and maximum level of the color-coding

  • Enable logarithmic scaling by checking the checkbox.

  • Style: Selection of a transparent or untransparent background.

    Intensity Diagram of a Matrix Sampler channel without (left) and with level grading (right, 10 levels)

    Fig. 387 Intensity Diagram of a Matrix Sampler channel without (left) and with level grading (right, 10 levels)

Array Chart

Array Chart instrument – overview

Fig. 388 Array Chart instrument – overview

The Array Chart can be used to visualize the CPB channels of a CPB (Constant Percentage Bandwidth) Analysis (refer to CPB analysis).

Note

The maximum number of channels that can be assigned to one Array Chart is two.

The Array Chart has the following Instrument Properties:

  • Total Computation: It is possible to include a Total column (see Fig. 389) on the right hand side that display the following value:

  • None: No value will be displayed

  • Minimum: The minimum CPB value will be displayed

  • Maximum: The maximum CPB value will be displayed

  • Energetic Sum: The energetic sum across the CPB spectrum will be displayed.

  • 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

Array Chart with *Total* column included

Fig. 389 Array Chart with Total column included

  • Value Axis: Change the upper and lower limit of the Y-axis.

  • Style: Selection of a transparent or untransparent background.

Audio Player

Audio Player instrument – overview

Fig. 390 Audio Player instrument – overview

The Audio player Instrument can be used to replay OXYGEN channels via the systems’ default sound card.

The instrument provides the possibility to mute the channel(s) (Output enabled), to set the output Volume and to change to left-right Balance (see Fig. 390).

The maximum number of channels to be assigned to one Audio Player is 2. It is possible to replay synchronous data channels (i.e. analog inputs and formulas).

The recommended channel sample rate is from 1 kHz to 200 kHz.

Style: Selection of a transparent or untransparent background.

The audio replay functionality is available in LIVE, REC and PLAY mode. In LIVE and REC mode, the actual data is replayed. In PLAY mode the replay is snapped to the position of the Orange cursor (see Fig. 391).

Orange cursor in Overview bar and Recorder

Fig. 391 Orange cursor in Overview bar and Recorder