You can create and edit expressions by using the Expression Browser Dialog Box
. The Expression Browser is available next to any expression textbox. Go through the following steps to open the Expression Browser Dialog Box and edit or create expressions.
1. Drag and drop a Statement step into your Main Sequence.
2. Go the Expression tab of the step settings.
3. Expression Browser assists in constructing expressions. Click the Expression Browser button next to any expression textbox to launch the Expression Browser dialog box.
4. In the Expression Browser Dialog Box you can select variables and functions without having to know the exact syntax of the expression that you are wanting to execute.
Use expressions to programmatically access or change the data TestStand gathers as it runs a sequence. You can use expressions in the following places:
- Expressions panel
- Code module parameters
- Test limits
Different types of expressions exist.
- Data expressions are evaluated at run time and return a value TestStand passes
to the item for which the expression was designed. Parameter values are examples
of data expressions.
- Conditional expressions evaluate to a Boolean data item and determine whether
an If statement or precondition executes the steps within its block.
- General expressions do not return values but allow you to execute a statement and
assign custom values.