niDMM PXI-4072 fails to initialise

[DarenLadds]

For some reason our PXI-4072 is locking up and returning the status code 0xBFFA4011. There is no input to the module when this occurs. Any suggestions?

[Claudia]

Daren,

The error BFFA4011 is documented in the NI Digital Multimeters Help file (NI-DMM driver installs it in your PC and is accessible via the Start menu). The description of the error is as follows:
"NIDMM_ERROR_DEVICE_IN_USE_BY_PROC The device is already in use by another process. Verify that all sessions of the device from other processes are properly closed."

You could get this error if you are running the Soft Front Panel using your PXI-4072, and then you try to run the niDMM Initialize function from your programming environment (like from LabVIEW).

If you are not running any application with the PXI-4072, could you describe in what programming environment are you getting this error and the steps I could take to try reproduce it?
Other information that would be helful: version of NI-DMM driver installed in your PC, whether the PXI-4072 passes Self-Test and Self-Calibration in MAX.

Thanks,

Claudia L
DMM R&D
National Instruments

[DarenLadds]

Claudia,

Thanks for the reply. Your description of the error makes some sense. We are currently debugging our CVI application and are stopping execution before we reach our calls to close the device sessions. The error only appeared a couple of times today, even though we have been stopping execution on ever run.

When we use MAX to try and reset the DMM, after it fails to initialise in CVI, we are getting a similar error.

We are using CVI version 7.1.0 and niDMM driver verision 2.3.1

Thanks

Daren

[Claudia]

Daren,

This is expected behavior due to an abnormal termination of your CVI exe when two processes are running (that is, when both your CVI exe and MAX are running) and one of the process is terminated without closing correctly the session to the PXI-4072.

You would get error BFFA4011 if you:
1. Open MAX (process 1) and run an action that opens a session to the PXI-4072 (like Self-Test, Reset, or just expanding "Devices and Interfaces", which opens a session to the DMM to retrieve information from the board, like the calibration information)
2. Run your CVI exe (process 2) and terminate it inapropriately
3. Try to run Self-Test, or Reset, etc in MAX.
Throughout all this time both processes were running so the memory allocated by DMM never gets released appropriately.

You would NOT see this error if you:
1. Run your CVI exe and terminate it inapropriately
2. Try to run again your CVI exe
You will see that under this circumstance you do not get the error saying that the device is already in use by another process.

If you are debugging your CVI exe and you are planning on terminating the application without closing the session appropriately using niDMM_Close, use one of the following options to avoid getting this error:
1. Before terminating your CVI exe let it close the session to the PXI-4072 using niDMM_Close
2. If you terminate your CVI exe without closing the session, make sure you close MAX afterwards. Then you can re-open MAX to run Self-Test, Reset, etc.
3. Make sure MAX is closed before you begin debugging your CVI exe. This way, after you terminate it abnormally (without calling niDMM_Close) you can open MAX and run Self-Test, Reset, etc without getting the BFFA4011 error.

Please reply to this post if you need further assistance. Regards,

Claudia L
DMM R&D
National Instruments