Predefined Sequences
A LTT testplan need to have certain predefined sequences.
See chapters order of execution, operation modes and process model for a better understanding.
The green and purple sequences at the top are predefined mandatory TestStand sequence callbacks triggered by the process model. They will be triggered in the following order.
- SequenceFileLoad: called at sequence file load. Initializes limits.
- ProcessSetup: called one time after start for all stations. Use this to perform initializations per LTT and not per DUT.
- PreUUTLoop: called one time after start for each DUT.
- MainSequence: main sequence entry point. Do not make any changes here. It serves as a dispatcher to the various operation mode sequences.
- PostUUTLoop: called one time during stop for each DUT.
- ProcessCleanup: called one time during stop for all stations. Use this to perform cleanup per LTT and not per DUT.
Additionally to the standard TestStand sequence callbacks there are a couple of other, optional sequences.
| Sequence | Outcome |
|---|---|
| Sync | Synchronizes the execution of all stations at this point. Optionally sets the power supply to a different voltage level. |
| MesSy Setup | Performs the MesSy setup. |
| MesSy Analog Config | Configures MesSy analog channels (scaling, offset). |
| MesSy Activate Limits | Activates a given limit set on MesSy. |
| MesSy SSV Check | Performs a SSV check on a given limit set. |
| MesSy Clear Errors | Clears any previous SSV check results. |
Besides those standard and optional sequences above, there are so called operation mode sequences, which are important for the LTT.
A LTT testplan need to contain at least one operation mode sequence.