Before executing the steps in a sequence, TestStand creates a run-time copy of the sequence to maintain separate local variable and step property values for each sequence invocation.

A sequence context is an object in the TestStand API that represents the execution state of a sequence. For each active sequence, TestStand maintains a sequence context that contains a reference to the run-time copy of the sequence so you can access all the objects, variables, and properties that relate to the execution of the sequence.

The contents of the sequence context vary depending on the currently executing sequence and step, the location of the active sequence in the call stack, and the identity of the execution in which the active sequence resides. Depending on the current state of execution, sequence context subproperties might not exist. When a property exists, the contents of the property can vary.

The sequence context Step subproperty is an example of a property that depends on the execution state. During execution, the Step property exists only when a step is executing. When execution suspends between steps, the Step property does not exist. When it exists, the contents of the Step property are the contents of the currently executing step.

Referring to Subproperties

To refer to a subproperty, use a period to separate the name of the property from the name of the subproperty. For example, refer to the CurrentUser subproperty in the TS subproperty of the StationGlobals property as StationGlobals.TS.CurrentUser.