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VISA read Problem: After a while the device stop responding

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Hi everyone,

I am facing a really strange bug that anything that I have done could not solve it. I have a PIC device that I made myself communicating with LabVIEW by a RS232 -> USB converter. Everything seems to be ok, but suddenly (it can last 30, 45 or 50 seconds), LabVIEW stops receiving data and any buttons do not respond anymore, not even the stop button. I have to remove the usb converter to get the buttons to respond again, and then I got the error:

 

Other programs that opens this same terminal can communicate with my device for hours without errors. I sure open the session and only close after the while loop. Can anybody help me?

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Solution
Accepted by topic author FilipeTaveiros

How fast is your VI reading the com port?.. could it be trying to read from it too fast?.. add a wait in your VI and see if that helps.

 

 

Just a thought..

 

Josh

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Thank you for your answer. LabVIEW is reading the COM port every 1ms. Also, the code has a queue to ensure the COM input buffer to work near empty. The queue also works fine, with 1 or 2 elements queued. So, it can be said that the writing / reading is almost synchronized. It works fine for a moment then just stops receiving data, and all LabVIEW buttons dot not respond until I remove the USB cable.
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Hello,

 

Same problem for me! It can last 1 hour or 5 hours but at some point the two parts of the program that have a RS-485 to usb stop. This program was working perfectly until I changed the computer. The OS was vista (32 bits) and it is now 7 (64 bits). This is the only thing that has changed.

 

I also found that if more parts of the program are running this problem appears earlier. It was definitely not issue before since the program could be running for weeks.

 

Thanks for your help.

 

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