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cDAQ hardware requires power reset after VI exit.

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My LabVIEW program seems very simple. It uses two Express VI's, one analog input (NI9219) and one counter input (NI9411). The program runs fine until I stop it. Then it will not start again unless the cDAQ chassis (NI9472?) is power cycled. The program just sits there and does nothing. When I reset the chassis and click the run button the program starts and runs perfectly. The only part of the program that is slightly unusual is that the counter input references the analog input sample clock (ai/SampleClock?) for synchronization.  The sample timing mode is "continous" for both modules. Why does resetting the chassis make eveything work correctly? How can I eliminate this step?
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Message 1 of 10
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Hello,

 

Can you attach your VI to the forum?  That will help others to debug your application.

 

Regards,


Kyle

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Message 2 of 10
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A copy of the VI is attached.
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Are you stopping the VI with the stop button on the front panel or by using the Abort button?
Seth B.
Principal Test Engineer | National Instruments
Certified LabVIEW Architect
Certified TestStand Architect
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Seth,

 

It doesn't matter whether the stop button or abort button is used to stop execution, the chassis has to be reset before starting the program again.We have 8 computers and 8 cDAQ chassis all configured identically. They all do this. 

 

thanks!

 

 

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Message Edited by EEsRULEtheWORLD on 04-07-2010 02:39 PM
Regards,

Sara Lewandroski
Applications Engineer | National Instruments
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Hi querty999,

 

It seems as if I ran out of time to adjust my previous post.  😕

 

I tested your VI with simulated devices on my end, and everything seemed to work fine.  Does this same behavior occur if you are running only the counter task? or running only the analog input task?

Regards,

Sara Lewandroski
Applications Engineer | National Instruments
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Solution
Accepted by topic author querty999
Try wiring your Stop button into the DAQ assistants as well.  The tasks are set up for continuous samples, and are never actually instructed to stop.  I'm wondering if that somehow is causing a buffer overflow error or something like that and is causing USB communication to lock up.  I would say it shouldn't, but it would be worth trying.
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Thanks Ravens,

 

Your solution worked.

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Just to update everyone, this is related to an open Correct Action Request (CAR) #207677.  We are investigating the root cause and working on a fix to help prevent similar issues in the future.

 

Regards,

Seth B.
Principal Test Engineer | National Instruments
Certified LabVIEW Architect
Certified TestStand Architect
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