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Signal Express - Tektronics Single Sequence

Beginner on first day with Signal Express and Tektronics TDS2024B Scope.
I want to set the scope trigger to single sequence and wait for Acq Complete before going to my Acquire Signal Step.  I think I need a "user-defined LabVIEW VI" step.  What tools do I need to make or get a step to set and then querry the scope trigger?
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Message 1 of 5
Are you using the Tektronix edition of SignalExpress?  If you can use use the Tek 2k step to setup the triggering to do this.  Make sure that the Trigger Mode is set to Normal if you only want a signal when a trigger occurs.
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Message 2 of 5

Thanks Chris,

Yes I am using the following:
Express Work Bench 1.5.0  Signal Express 1.2.0  Tek Edition 1.1.0
Tek TDS2024B scope USB

My problem is that the steps repeat continuously even if there has not been a newly triggered scope event to look at.  This repeating loop piles on to the appended output file (or adds the next named output file) continuously repeating the same scope data.  So I think I need a step to querry the scope to see if it has been triggered before repeating the acquire input step and generate output step.

By looking at the scope and using OpenChoice Desktop to look at settings their are four states of interest.  I think I want to be in the first or second state.  In the first state I wait.  Iin the second state I do the acquire input & generate output steps and wait again until querries of the scope return acquired status.

Single Sequence Ready

Single Sequence Acquired

Run/Stop Ready

Run/Stop Stopped

Note:  I put in a request here at work for a LabView license seat so I can learn how to create a user defined VI to querry the scope.


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Message 3 of 5
(5,486 Views), the acquire input step available in WorkBench Express/SignalExpress/Tek only knows about normal trigger and auto trigger, not single sequence.  So once a triggered event comes in, the scope goes from "Ready" to "Trig'd" and immediately back to "Ready".   Thats why I think I need the single sequence and acquired status.


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Message 4 of 5
Yes, the single sequence functionality was missing from the Tektronix step in that release. We plan to remedy that in our next release of the Tektronix steps. You might try using the IVI Scope step with the tektronix instrument. It actually supported waiting for the trigger to occur. It is a little more difficult to get all the settings right for this step as it is not tailored specifically for any instrument, but it should wait for the acquisition to complete (or timeout, according to the Timeout control) before continuing.
Let us know if this addresses your problem.
Patrick Christmas
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