Using windows messaging to control automatic test equipment

Traditionally, Test Program Sets (TPSs), written in ATLAS for Automatic Test Equipment (ATE), were developed for use with sequential, single tasking systems. For the F-16 Analog Test Station Sustainment (FATSS) project, TPSs were implemented in a separate thread enabling the operator to activate controls on the Test Executive while the TPS thread executes. When the operator activates a control on the Test Executive screen, a windows message is sent to the TPS thread, causing if to be suspended, single stepped, or aborted. Without multi-thread support, the operator would be forced to wait until a task completes before making changes. The operator would also be forced to reboot the computer or kill the test session in order to stop a test from executing. Under runaway burn conditions, or with extremely long delays, waiting for a task to complete becomes unacceptable. Legacy system flow controls such as the Auxiliary Keypad on the Honeywell 2600 used hardware interrupts to control the flow of the TPS. These controls are now implemented in software on the Test Executive screen. Using this method, the operator will be able to cancel the program execution by pushing the Station Clear button, or to change flow control values such as Repeat Test, or Hold on NoGo buttons, while the translated ATLAS executes in a separate thread. Rehosting these TPSs to a windows environment also enables us to attach new control devices to the system such as the mouse and voice control.