You could debug into your step by follows these instructions: http://digital.ni.com/public.nsf/websearch/52f5bb7ae7f5a409862569ee0073ac53?opendocument, if its the step code thats causing the problem.
What step is next executed when you press F8 again after the step returns pass?
It could be your sequential model because your are using Selected Step using Single Pass, which means you are using the process model eg your sequential model sequence file.
Hi Ray and thanks...
The link does not help me...
I'm still not clear as to what manage the steps. I understand that the sequential model calles the MainSequence. Then, the in the MainSequence there is a setup, main and cleanup parts. What I've seen was that the step passed (it was the only step selected), when I hit the F8 (next step) one more time, it was supposed to jump into the cleanup part. I put breakpoint in the first step of the cleanup to see if the error comes from there...but found out that it happened before it reached it. so, the question again is what happens between the end of the 'Main' part and the beginning of the 'cleanup' part? who is handling it? and where?
Do you have any of the PostStep or PostResult or PostInteractive sequence callbacks in either your SequenceFiles or the ProcessModel sequence file you are using.
Is the step type a custom step type?
The Teststand engine is managing the steps and is executing the order of steps based on the Entry Point to the Process Model, in this case Single Pass. Therefore, it going execute the Single Pass sequence, if you have any override callbacks, apart from the MainSequence, in your Sequence File, then it will invoke those instead of the of the sequence in the Process Model. Once it gets to the MainSequence, it will execute the steps in your SequenceFile, as you say. In all cases, it will perform the steps in the Setup, then Main and finally the Cleanup.
So, if it hasn't got to the Cleanup, then maybe its in one of the PostStep sequences or maybe you have a SubPostStep in your custom steptype its running. Try enabling some of the tracing in the Station Options | Execution.
Thank you very much for the clarification.
I'll look into it more closely. In the meantime, i solved the problem by creating a new step with a new definitions of the parameters and indeed it works fine.