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crio 9074 with timed loop synced to scan engine only running one cycle

I have a timed loop acquisitioning data from an NI CRIO 9074 with a digital C Module.  The timed loop is set with the NI SCan engine as the source type and the loop timing attributes to a period of 1 scans and prioirty of 100. 

 

The loop only runs one iteration...

 

I then change it to running off of the 1kHZ Clock which defaults to a period of 1 ms and a prioirty of 100 and it runs forever.

 

My scan engine is set to a period of 1 ms in the dialog for the chassis in my labview  project and there are lots of errros listed in the fault configuration section starting at code -166460 which says the io scan time exceeded the NI Scan period that you specified on the the scan engine page of the target properties dialog box.  

 

attached is the project code and some screen dumps of it.

 

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Where is your VI that runs on the cRIO?  That is the VI that can access the Scan Engine timing.  I do not understand what you are trying to do here.


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ad scan engine.vi is the labview rt vi that runs on the rio...it runs and it works when the vi timed loop is not synced to the scan engine. 

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@id wrote:

ad scan engine.vi is the labview rt vi that runs on the rio...


Not as you currently have it set up.  The VI is under My Computer, which means it runs on your PC, not the cRIO.

 

Your error is saying that the Scan Engine cannot go through all of your channels fast enough.  My first recommendation would be to remove all of the channels that you do not actually use.  Secondly, there is no reason for the sequence structure.  All it is doing is slowing down your loop.  Thirdly, you may have to slow down your Scan Engine update rate.  The Scan Engine is not really meant to do into the kHz update rate.  The fastest I have had luck at is more around 10ms update rate (100Hz).


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that did it thanks.  Why doesnt the scan engine tell you that the thing is set too fast somewhere?  My program just runs a single while loop iteration and then quits with no errors reported

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