NI 5680 Read Error

[LabTech]

I am reading from a NI 5680 RF power meter in a while loop and sometimes the ni568x Read vi returns error -1073807339 which is a timeout before operation completed problem. Normally a read takes approx. 100 ms and when the error occurs it is at approx. 1.5 s. Obviously even 1.5 s indicates a problem but I'm also not sure why it does not wait the 5 seconds embedded inside the read vi before returning an error. What might cause this problem?

[Doug_L._Bear]

This error could be because of poor USB connection in addition to a timeout error.  Are you going through a USB hub or plugged straight into the computer?  If through a USB hub try straight into the computer.  You may also want to try adding a manual timeout to the read and see if that affects your behaviour. 

This is an underlying VISA error which is the protocal that facilitates the USB communication which is why I am leaning more towards the first issue of USB connectivity.

[mbb25]

I'm seeing the same problem: intermittent time-out after only 1.5 seconds.

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Error -1073807339 occurred at ni568x Read.vi

Possible reason(s):
Error: (Hex 0xBFFF0015) Timeout expired before operation completed.

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I'm attaching the VI that I used, with the defaults saved for one of the failure runs (ran 3x, failed on two of them).  Actually, I'll attach 2 VIs.  Another way I've seen this is a timeout (just over 1.5 seconds) during ni568x Configure Correction Frequency.vi, but this VI is written a little differently.

My machine is a Dell Precision 390.  I first saw this problem a long time ago, and it seems like it went away after a while. Maybe I started setting the number of averages to something other than 0.  I'll attach one more version of the VI that shows my results when I use 3 averages instead of 1.  I still get funny timing (most measurements take 250 ms, some take 1.5 s), but at least I don't get an error.  Maybe that work-around will help until the root cause is found and fixed.

[LabTech]

Hi Doug, I am going through a hub at this point and I am going to try a direct connection today. Is there a general problem with using a hub or is it more likely to be an issue with the quality or design of some hubs? Bob

[LabTech]

I tried a direction connection and the read error still occurs.

[Doug_L._Bear]

I don't have a 5680 right now to test your code but it looked fine.  The comment that this can happen with the configure frequency VI leads me even more towards thinking this is an issue with USB connectivity.  We do sometimes have issues with our USB devices going through hubs, though it usually is the quality of the hub we just recommend not going through any at all as its impossibly for us to test every possible USB hub out there.

I would recommend you try using Soft Front Panels and see if it is working that way with the same configuration settings.