TestStar Function Generator

Use the Function Generator to generate a wave form to command the servo control loop.

Define

Use the Define menu to create the servo loop command , set up the counter , and establish the home  function.

Stop

Ends the test and causes the program command to return to the mean level.

Hold

Suspends the program command until you press the Run, Stop, or Home pushbutton.

Run

Starts the program command described in the Define area.

Home

Executes a ramp from the current output to a predefined output. You define the Home ramp with the Home Menu Option window.

Mean

Introduces an offset that references the command to a level other than zero. Pressing the Mean pushbutton displays a Set Scroll Range window where you can change the maximum and minimum values of the Mean adjustment.

Amplitude

Establishes the span (peak-to-peak amplitude) of the command. Pressing the Amplitude pushbutton displays a Set Scroll Range window where you can change the maximum value of the Amplitude adjustment.

Frequency

Adjusts the frequency of the command. Pressing the Frequency pushbutton displays a Set Scroll Range window where you can change the maximum value of the Frequency adjustment.

Amplitude/Mean Control

Adjusts the servovalve command signal until the programmed amplitude is achieved and the mean level is maintained. This ensures that the programmed amplitudes and mean levels are applied to the specimen.

Definition

Shows the current command definition created with the Command Menu Options  window

Status

Shows the status of the counter and the test command.

Using the Window

1	Select Command in the Define menu.

2	Complete the Command Menu Options window to define the servo loop command. The command definition appears in the Function Generator window.

3	Select Counter in the Define menu.

4	Turn on the Preset Count. Enter a Preset Count to stop the program command at a specific number of cycles. Enter a 0 Total Count to clear the counter. Turn off the Preset Count to cycle continuously.

5	Select Home in the Define menu.

6	Complete the Home Menu Option window to define the Home pushbutton ramp. A typical home ramp returns the actuator to its starting position.

7	Set the Mean level for the program command.

8	Set the Amplitude of the program command.

9	Set the Frequency of the program command.

10	Press the Run pushbutton to start the program command. While the test is running you can press the Hold pushbutton to suspend the test at the current output. Press the Run pushbutton to resume the program command.

11	Press the Stop pushbutton to end the command. At this point you can change the command definition and run the new program command.

12	Press the Home pushbutton to return the actuator to the Home position.

More Information

Detailed information about this window can be found in Chapter 6 of the Reference manual. A procedure for using this window can be found in Chapters 4 and 6 of the Operator's Guide.


Define Menu

The Define menu shows the 3 components that create a test command.

Select Command  to create the basic wave form command.

Select Counter  to define the counter function. Select Home  to define the home ramp.


Command Window

The Command Menu Options window defines the servo loop command wave form.

Control Channel

Specifies the control channel for the command parameters shown in this window.

Control Mode

Specifies the control mode for the servo loop command. Only the control modes created for the selected control channel are available.

Units

Select the units you want to use for the Initial Ramp Rate, the Mean adjustment, and the Amplitude adjustment.

Initial Ramp Rate

Specifies the ramp rate from the starting level of the actuator to the mean level setting when the test begins. The starting position of the actuator is typically the zero reference of the program command.

Waveshape

Specifies the type of waveform. Select a sine, square, or triangle waveform.

Waveshape order

Determines if the waveshape starts positive or negative. When the Inverted box is checked, the waveform starts negative.

How it Works

After you define a function generator program and press the Run pushbutton, the following occurs:

The initial ramp executes to achieve the mean level setting.

The waveshape order selection applies the waveshape from the mean level to the amplitude end level

The waveshape cycles according to the requirements of the amplitude, frequency, and preset count.

The Home pushbutton executes a ramp to the home position.

More Information

Detailed information about this window can be found in Chapter 6 of the Reference manual. A procedure for using this window can be found in Chapters 4 and 6 of the Operator's Guide.


Counter Window

This window configures the counter to cycle continuously or to stop the waveform after a preset number of cycles.

Preset

Turning the Preset Count Off causes continuous cycling. Turning the Preset Count On sets the counter to value entered in the Preset Count entry field. A preset count of 0 causes the waveform to execute a half cycle (a single segment).

Current

Displays the current count. Select the entry field and type 0 to clear the current count. When the current count equals the preset count, the waveform stops.

Total

Displays the total count. Select the entry field and type 0 to clear the total count. Use the total counter to keep a cumulative count.

More Information

Detailed information about this window can be found in Chapter 6 of the Reference manual.


Home Window

The Home Menu Option window defines a control mode and end level that is assigned to the Home pushbutton. Pressing the Home pushbutton causes the servo command to ramp from the current servo control setting to the defined end level (usually the starting position or zero reference). The Home function can be defined as a ramp in a test or, to return the actuator to its starting position at the end of a test.

The home ramp does not have a ramp rate. The ramp executes from any starting position to the defined end level in the amount of time specified.

Control Mode

Specifies the control mode for the home ramp when the Home pushbutton is pressed. Select a control mode.

Endlevel

Specifies the end level the servo loop achieves when the Home pushbutton is pressed. Select the units for the end level and enter the end level value.

Time

Specifies the amount of time the ramp executes. Enter a time value in seconds.

More Information

Detailed information about this window can be found in Chapter 6 of the Reference manual.


Scroll Range Window

Setting the scroll range ensures the maximum adjustment of the control is within the capabilities of your equipment. Reducing the scroll range also increases the resolution of the control adjustment

More Information

Detailed information about this window can be found in Chapter 6 of the Reference manual.