Because LabVIEW operates on a data flow model and TestStand generates events, updating the state of execution while handling events might become a complex task. However, the Semiconductor Module Manager object handles most of these events and state management for you. The TSM default operator interface uses the Command Button.lvclass class to bind LabVIEW button controls to commands in the TSM Application API. The command objects generate events the Command Button uses to update the state of the button.

For all other controls, the main execution loop of the Top-Level VI calls the Refresh Callback VI of its connected class each iteration and updates the state of the control using information the TSM Application API provides.