Sequence Development & Customization Flashcards

In TestStand, which mechanism allows a single sequence to be reused across different projects while maintaining project-specific behavior differences?

Answer: Sequence inheritance using Template sequences with overridden callback steps

Template-based sequence inheritance allows shared base logic while permitting individual projects to override specific callback steps for custom behavior.

A CTA needs to ensure that a specific set of steps always runs in a defined order, even if parallel execution is enabled. Which TestStand feature enforces sequential ordering within a parallel context?

Answer: A Batch Synchronization step with all threads at the same gate

Batch Synchronization steps act as barriers that halt all parallel threads at a gate until every thread arrives, then release them together in controlled order.

Which TestStand expression function would you use to determine the number of elements in a sequence's array variable at runtime?

Answer: GetArrayDimSize(Locals.MyArray, 0)

GetArrayDimSize returns the size of a specified dimension of an array, which is the standard way to get element count in TestStand expressions.

What is the correct way to catch and handle a specific error code from a code module in a TestStand sequence without stopping execution?

Answer: Set 'Ignore Run-time Errors' on the step and check Step.Result.Error afterward

Enabling 'Ignore Run-time Errors' prevents the error from propagating, then the Post-Expression or subsequent steps can inspect Step.Result.Error.Code to handle specific cases.

A test sequence must dynamically load different code modules based on a hardware configuration variable. Which TestStand feature supports this?

Answer: Expression-based module path in the code module call step

TestStand allows the code module path in a call step to be an expression, enabling runtime resolution to different DLLs or VIs based on configuration variables.

In TestStand sequence development, what is the function of the 'Sequence File Load' callback?

Answer: It executes custom code whenever a sequence file is loaded into the engine

The Sequence File Load callback fires each time a sequence file is opened, allowing developers to perform initialization tasks specific to that file's requirements.

Which approach best prevents race conditions when multiple parallel threads in a TestStand sequence write to the same shared variable?

Answer: Protect write access using a Batch Synchronization or Critical Section step

Critical Section or Batch Synchronization steps serialize access to shared resources, preventing concurrent writes that could corrupt data.