What is the purpose of "loop callbacks" in the sequential model single-pass entry point?

[bienieck]

Why Single Pass entry point in SequentialModel.seq includes PreUUTLoop Callback and PostUUTLoop Callback? This entry point does not have a loop for sockets, so what is the point?

[WireWeaver · Accepted solution]

I haven't been at NI long enough to know the exact historical reason, but my guess is just for parity with the Test UUTs entry point. Here's an example of where that might be useful:

• I have some big LED/Indicator on my test station that i want to turn on whenever someone is running tests to express "somebody is using this test station"
  • I turn it on in PreUUT Loop and off in PostUUT Loop so it's not off periodically between each UUT.
• I have some small LED/Indicator on the test fixture to let the operator know "this is the actual UUT that's being tested right now"
  • turn it on in PreUUT and off in PostUUT

Overriding both callbacks in a client file lets you get the same LED behavior with both entry points, without having to the modify the client file. My example probably isn't the best - i suppose ProcessSetup and Cleanup would work just as well for the big LED, but there are some other reasons those callbacks exist...

Hope that helps!

Trent

[bienieck]

You might be right. I was analyzing a single pass entry point without thinking that it is a part of the process model that has two possible entry points. But now it makes sense.

Thanks.