TestWare-SX File Playback

A file playback process produces a command signal that controls a servovalve or servomotor. This process should be sequenced in series with other command processes.

Prerequisite

You also must create a playback file for use with the process. You should also be familiar with the type of information in the file.

How it works

The file playback process uses an ASCII file (that you create) to function like a series of monotonic processes. A playback file specifies a waveshape, rate type, and end level for each command segment.

A playback file can include up to four groups of data. These groups can be used for a four-channel test or four separate tests in a single-channel system.

The end level data can be entered with common units or normalized units. When a playback file is selected, it is scanned to determine what kind of units are appropriate for the test parameters. Normalized units can be expressed as a percentage of full-scale or multiplier values.

The waveform can be scaled by parameters that multiply the time base, amplitude, and mean level. A runtime compensation window allows you to manually adjust the mean level and amplitude of the waveform.

Each segment command from the playback file identifies a waveform shape, a rate type, and a segment end level. The file is read in sequence to produce a waveform.

Waveform compensation can be disabled, manually scaled or automatically optimized using a spectrum amplitude control (SAC) algorithm.

Manual compensation is accomplished with parameters that multiply the time base, amplitude, and mean level. Use the runtime compensation window to manually adjust the mean level and amplitude of the waveform while the command is running.

SAC compensation is accomplished with an algorithm that uses a table while the test is running to keep track of end levels. Each command end level is compared to its feedback end level to determine if an over programmed level is needed. Each time the file is run, new compensation values can be established or existing values can be used. See How SAC Works for more information.

More Information

You can find detailed information about this process in Chapter 6 of the 790.10 TestWare-SX Application Manual.

The File Playback Design window names the process and sequences it in a test template.

The File Playback Parameters window accesses the Select End Level File window to open a playback file and assigns appropriate units for the control mode.

The Select end level file window opens a playback file.

The File Playback Compensation window allows you to manually adjust the mean level and amplitude while the process executes.

The Set Mean Scroll Range window changes the range of the Mean adjustment in the Compensation window.

The Set Amplitude Scroll Range window changes the range of the Amplitude adjustment in the Compensation window.

The Define SAC Compensation Parameters window sets up the spectrum amplitude control compensation feature.

The SAC CompensationRange window is a run time window for SAC feature. Use it to monitor missed end levels and enable learning mode.


File Playback Design Window

This window specifies when the process starts and stops. The information in this window is saved with the test template.

Using the window

Use this window to create a process that reads an ASCII file to control the test command.

1	Name the process with the Label entry field.

2	Select a Start Trigger to sequence the process. This process should be sequenced in series with another command process.

3	Select an End Trigger to stop the process. Use the default none trigger if you want the process to complete without interruption.

4	Select a Control Channel for the process.

More Information

You can find detailed information about this process in Chapter 6 of the 790.10 TestWare-SX Application Manual.

Go to How it works for an overview of the process.

After you complete this window, you can double-click the name of this process in the Edit Template window to display the File Playback Parameters window. This allows you to assign parameters to the default procedure.


File Playback Parameters Window

You must create a file playback process in a template with the File Playback Design window before you can run this process. The information in this window is saved with the test procedure.

File Name

Pressing the File Name pushbutton displays the Select end level file window where you select the file for this process.

Passes

Type the number of times the file is repeated. Enter 0 for continuous repeats.

Multiplier

Scales the time component of the waveform.

Compensation

Enables manual compensation (scaling) of the waveform. Select none for normal operation. The manual selection displays the File Playback Compensation window where you can adjust the amplitude and mean level of the waveform.

Define SAC

Displays the Define SAC Compensation Parameters window where you select a spectrum amplitude control table, table limit, and error tolerance.

control channels

Selecting a control channel displays its name to define the channel for the end level data, control mode, and level parameters.

End Level Data

Selects the end level data. Each playback file can have up to four columns of end level data. End level data is a list of values that specify the end level for each segment in the playback file.

Control Mode

Displays a list of the available control channels. The playback file determines which control modes are valid for the selected end level data.

Level Reference

Specifies a mean level offset that is applied to the end level data.

Level Multiplier

Scales the amplitude of the end level data.

Using the window

Before you use this window, you need to know some things about your playback file. It is a good idea if you have a printed copy of your playback file. Consider the following:

Is the playback file designed to be looped?

Is the time base (rate type) easily scaled with a multiplier?

How many groups of end level data are there?

Are the groups of data set up for multiple channels or iterations?

Is the end level data in normalized units or common units?

Perform the following:

1	Press the File Name pushbutton and select a playback file.

2	Enter the number of times you want to run the file in the Passes entry field.

3	Select a multiplier if the rate type value (time base) of the playback file is inappropriate for the test.

4	Enable compensation if you want to manually adjust the mean level and full scale amplitude of the test.

5	Select a control channel from the unlabeled scroll box.

6	Select the appropriate group of end level data.

7	Select the control mode for the channel.

8	If necessary, enter a level reference value to offset all of the end level data values.

9	If necessary, repeat steps 5 through 9 for each control channel.

More Information

You can find detailed information about this process in Chapter 6 of the 790.10 TestWare-SX Application Manual.

Go to How it works for an overview of the process.


Select End Level File Window

Use this window to select the ASCII file for the file playback process.

File

Displays *SFP in the entry field when the window appears. The file name *SFP causes all files with the SFP extension to be shown in the Files list. All playback files should use the extension SFP.

Current Directory

Displays the path of the current directory. When you select a different directory, the directory path is updated.

Files

Lists the playback files in the current directory.

Directories

Lists the available directories. Double-clicking a different directory displays the new path next to the current directory label.

More Information

You can find detailed information about this process in Chapter 6 of the 790.10 TestWare-SX Application Manual.

Go to How it works for an overview of the process.


File Playback Compensation Window

Use this window to manually adjust the mean level offset and amplitude of the file playback process.

Prerequisite

The compensation selection in the File Playback Command window must be set for Manual.

Using the window

This window appears when a file playback process is being executed and the compensation function is enabled.

Select a control channel, then adjust the controls for that channel. One channel can be adjusted at a time.

The controls can be adjusted only while the process is being executed.

Pressing the Mean pushbutton displays the Set Mean Scroll Range window where you can change the maximum and minimum values of the Mean adjustment.

Pressing the Amplitude pushbutton displays the Set Amplitude Scroll Range window where you can change the maximum and minimum values of the Amplitude adjustment.

More Information

You can find detailed information about this process in Chapter 6 of the 790.10 TestWare-SX Application Manual.

Go to How it works for an overview of the process.


Set Mean Scroll Range Window

This window changes the range of the Mean adjustment. Set the range to ensure the mean level control can_t be adjusted beyond a safe range.

Min

Sets the lowest value of the Mean control. The minimum setting affects the left side of the Mean scroll bar.

Max

Sets the highest value of the Mean control. The maximum setting affects the right side of the Mean scroll bar.

units

Displays the units of the selected control mode.

Using the window

The window displays the full-scale value of the selected control mode range. You can change the maximum and/or minimum setting of the Mean control to a value less than full-scale. The Max and Min limits can be set to different levels.

You cannot set the maximum range to a value less than the current Mean setting or the minimum range more than the current Mean setting. Reducing the scroll range also increases the resolution of the control adjustment.

To change a scroll range value, type the new value in the entry field.

More Information

You can find detailed information about this process in Chapter 6 of the 790.10 TestWare-SX Application Manual.

Go to How it works for an overview of the process.


Set Amplitude Scroll Range Window

Setting the scroll range of the Amplitude adjustment ensures that the control is within a safe range. Reducing the scroll range also increases the resolution of the control adjustment.

Using the window

The window displays the full-scale value of the selected control mode range. The default value represents the span between ±full-scale. You can change the maximum setting of the Amplitude control to a value less than full-scale, but not below the current amplitude setting. The maximum setting cannot be set below 0.

To change the scroll range value, type the new value in the entry field.

More Information

You can find detailed information about this process in Chapter 6 of the 790.10 TestWare-SX Application Manual.

Go to How it works for an overview of the process.


Define SAC Compensation Parameters Window

The purpose for the SAC (spectrum amplitude control) option is to better meet the end levels in a spectrum/random waveform. Use this window to create, save, select and use a SAC table.

Control Channels

The SAC file can be applied to one control channel. Selecting a control channel displays its name to for the compensation parameters of the process.

Table Options

Use Create along with the Save SAC table to file option) the first time you run the playback file.

Use Load to open a SAC table you previously created for the playback file. Loading an SAC table also displays the upper and lower limits that were assigned when the table was created.

Select Use when you want to use the SAC table that currently exists in memory when this process begins. This is useful when one SAC table has been optimized for a test with multiple playback files.

Additional Options

Enabling Save SAC table to file writes the current SAC file to disk when the process ends. This option is available for all three table options.

Enabling Default Table Limits sets the upper and lower table limits to the range of the control mode. This option is available only when you are creating a an SAC table.

Error Tolerance

Specifies a range for the missed end levels count in the File Playback Compensation window.

Upper and Lower Table Limits

Shows the limits of the SAC table when it was created. The default setting is 0 which is 100%.

SAC Load File

Displays the Select SAC file window where you open an SAC table file. The complete file path is displayed in the entry field below the pushbutton.

SAC Save File

Displays the Select SAC file window where you save the SAC table file. The complete file path is displayed in the entry field below the pushbutton.

How SAC works

Spectrum Amplitude Control (SAC) is an algorithm that uses a table while the test is running to keep track of end levels.. As the test is running, the controller monitors the test progress and compares each command end level with its feedback end level. The difference between the command end level and its feedback is continuously monitored and the over programmed level is adjusted continuously.

More Information

You can find detailed information about this process in Chapter 6 of the 790.10 TestWare-SX Application Manual.

Go to How it works for an overview of the process.


SAC Compensation Window

Use this runtime window to select the SAC Learning function and monitor missed end levels and table limits.

SAC Learning

The learning function optimizes a SAC table after the table has been created. The learn function compares each playback end level plus its associated SAC value with the actual end level and calculates a new SAC level. If the save option is selected in the SAC Compensation Parameters window, the revised SAC table replaces the current SAC file.

More Information

You can find detailed information about this process in Chapter 6 of the 790.10 TestWare-SX Application Manual.

Go to How it works for an overview of the process.