DevNames returns error

[craige]

I have a PXI-1050 chassis running an 8186 real time controller.

I've been using the following VI for the past year without any problems. I recently started receiving errors from the PXI chassis when I attempt to call DAQmx System-> Device Names property. Error -201509 - Devices Cannot be identified.

I should receive an array of resources in the following format "Dev1, Dev2, Dev3,etc) but it just returns an error now. I've included the attached VI. I'm wondering where does this property get this information? Is it possible that a file on my real time controller has been corrupted or is that even related?

Thanks,
Craig

[craige]

Ok, I found out what the problem was so i'll document it here for others in the future. Somehow my chassis and controller lost their identification. When I went to MAX the tab labeled 'PXI System' said Unidentified and so did the Chassis node below that. I simply assigned controller and chassis to their appropriate values (in my case I have a PXI-1050 chassis running a 8186 controller).

I saved the configuration and rebooted my PXI and everything came back online.

Questions still remain:

1) I don't remember ever configuring the identification in the past so why didn't these values just automatically discover like before?

2) Where is this information stored in the PXI system? 

3) How is it possible to lose this information?

Thanks,
Craig

[Eriquito]

Hi craige,

I'm glad to hear you were able to resolve your problem.

FYI, the RT controller stores the configuration data in the following files:

# /ni-rt/system/config3.mxs
/ni-rt/system/config3.mxd
/ni-rt/system/max.ini
/ni-rt/system/mxs.mxr
/ni-rt/system/mxsjar.ini
/ni-rt/system/*.mx5 (all files with the .mx5 extension in the directory)
/ni-rt/system/Last/* (all files in the directory)

If these files were deleted or corrupted somehow, that could explain how this information was lost.

If the configuration database is deleted, the DAQmx driver would discover the devices you had installed in random order and assign names sequentially to re-create it, so they might not be in the same order as before.

You can backup the data by going to File » Export.. in Measurement & Automation Explorer on a host computer and exporting the configuration data of your RT target.

There was also a certain version of the DAQmx driver that had a bug that caused database corruptions.  If you have version 8.6, I highly recommend upgrading to the latest version (8.7.1) to reduce the possibility of this happening again.


Using NI-DAQmx 8.6.0f12 with PXI or Desktop Real-Time Systems -
http://digital.ni.com/public.nsf/allkb/DCC8D7530BA6DE16862573B00059E8AF?OpenDocument