Inline Transforms

To create a linear transform:

1.Select Project->Signal Dictionary from the main menu.

2.Select the Signal, and click Edit.

3.Select the Inline Transform tab.  

The linear transform allows you to specify a simple signal transformation in the form of y = mx + c, where m is a scale factor and c is an offset. Note that for Stimulus Signals x is the value from the Scenario and y is the value delivered to the SUT, and for Response Signals x is the value from the SUT and y is the value delivered to the Scenario.

•Scaling: Scale factor.  The default value for this field is 1.

•Offset: The default value for this field is 0.

In the example below, the Signal is a Response Signal because the data flow is from the SUT and towards the Scenario.  The value from the SUT is x and the value received by the Scenario is y.

You can implement your own Inline Transforms by entering snippets of C# code to perform the signal transformation.

Adding or Editing Code

Adding new transform code can be accomplished by clicking the New button in the Inline Transforms tab. This opens the C# Signal Transform Wizard. Enter a Transform Name. This name appears in the drop-down on the first transform page after the code compilation is done. The Edit button is used to edit the existing transform code referred by the transform name in the drop-down menu.

The transform source code files (.cs) are stored in the Transforms/CSharpSnippetTransform subfolder in the project folder.

Define Ports

Give names to  the In Port and Out Port signals (Default names are x and y respectively). Be sure to select the proper signal type. This window is also displayed when the 'Edit...' button on the Transforms page is pressed.

Define Transform

When writing the Transform code make sure to:

•Write the code in the User Code window.

•To use a Constant in your code, select it from the Constructs pane and click the up arrow.

•Click Compile to compile the code. Compilation errors, if there are any, will be displayed in the Notifications box.

•Click OK to complete the process.

•Click the buttons Compile, followed by OK even if the code you are Editing is not changed.

Testing Your Transform

After completing the compilation process, the transform name appears in the drop-down menu and the corresponding code appears in the User Code window. This code can be tested by entering a value in the Input Value window and clicking the '-->Test Transform-->' button.

Example of a Transform

A simple example of code for a Quadratic Equation "y = ax2 + bx + c"  is given below. y being the OutPort signal and x being the InPort signal.

int a = 1;

int b = 2;

int c = 4;

y = a * x * x + b * x + c;

Two other examples:

y = Math.Sin(t.Time_ns);

if (x == 1){y = 5;} else {y = 4;};

The TurnDoor Sample  has a good example of a powerful C# Inline Transform.  The LCD Bitmap Buffer Signal has an Inline Transform called VFDtoBitmap that takes the data stream of a vertically rastered image and converts it to a Windows bitmap, so that it can be displayed to the user.