daq-mx communication

[SPM]

Hi, all,

Occasionally, one of our control PCs loses communication with a DAQ-MX. How can I diagnose and correct this issue?

Thanks,

- Steve.

[Dennis_Knutson]

That makes no sense. DAQmx is software. Are you actually saying you lose communication with a DAQ device? If so, what kind?

[SPM]

USB-6501.

[Dennis_Knutson]

One thing to do is to make sure the USB port is not set to power down. Are you plugging it in to a direct port on the computer or an external hub?

[SPM]

I'm pretty sure it's not that. The communication failures are erratic and unpredictable.

[Dennis_Knutson]

What sort of error code do you get?

[SPM]

-50405: User-defined error code.

-S.

[Dennis_Knutson]

That is not a user defined error. It means:

NI Platform Services:  No transfer is in progress because the transfer was aborted by the client. The operation could not be completed as specified.

It would useful to see your code.

[SPM]

Weird about the error code. The interface software is LVOOP running under TestStand, and it's a bit convoluted. I'll get a screenshot if that would help.

Regards, -S.

[SPM]

Here are the VIs that do the raw bit manipulation. (I know they're inefficient but they do seem to work, until the device loses communication.)

Another data point is that Windows "finds" the device later, sometimes.

-S.