Expressions Panel

The Expressions panel specifies optional expressions TestStand evaluates before or after it calls the step module. It contains the following categories:

• Pre-Expression —An expression TestStand evaluates before it calls the code module . Use this expression to set the value of a custom step property from the values of other variables and properties.
• Post-Expression —An expression TestStand evaluates after it calls the code module. Use this expression to set the value of one of the subproperties in the Result property of the step based on the values of other variables and properties.
• Status Expression —Sets the Status property for the step. Because the status is a String property, this expression must evaluate to a string.

  If you leave an expression field empty, TestStand does not evaluate it.

  Note Certain types of steps, such as Numeric Limit Test , Multiple Numeric Limit Test , String Value Test , Pass/Fail Test , and Statement steps, reserve one or more of these expressions to perform operations specific to the type of step or a substep performs the operation. In these cases, you cannot use the expressions the step type reserves, which appear dimmed on the tab.