How do I create virtual channels in NI-DAQmx under Linux?

[jchrisj]

I looked around in LabView and couldn't find the DAQmx Delete Saved Global Channel vi or the DAQmx Delets Saved Tasks vi. In fact I can't find the Save versions of those vis either - I think that the Save Gloabl Channel vi that I'm using came from the "Programmatic Saves of NI-DAQmx Tasks, Channels, and Scales Example" that you pointed me at earlier.

Once the examples are loaded into LabView they work fine, but it seems odd that the Linux version wouldn't have vis that seem as basic as that.

When I do: nidaqmxconfig --export test.txt  and look at the text.txt file it generates, I find lines for the digital output modules that look like:

[DAQmxSCC SCCA-DO1]
ProductType = SCC-DO01
SCCModule.ConnBlk = SCCA
SCCModule.slot = 9

I've also got SCCA-DO2 in slot 10 and SCCA-DO3 in slot 11

SCCA is the SCC-2345 connected to DAC16A, the first (of 2) PCI-6221 cards. I can see the analog channels without difficulty. The system also has a PCI-6122 in it, but it is using its BNC breakout box.

thanks,
Chris

[Tom_W_[DE]]

Hi Chris-

The DAQmx Storage VIs (including Save Global Channel, Delete Global Channel, etc) are installed on the LabVIEW palettes as shown here.  I just verified this on my Linux RH4 test machine.

In order to see the DO channel in your physical channel control in LabVIEW, you may need to adjust the "I/O Name Filtering" setting for the LabVIEW physical channel control/constant.  You can access this menu by right-clicking on the control or constant.  I also verifed that I could see the SCC-DO01 channels by making this change on my Linux machine.  Incidentally, if you create the control or constant directly from an instance of DAQmx Create Channel>>Digital Output (by right-click>>create control on the physical channels input), the DO I/O Name Filtering setting will be made automatically.

Perhaps it goes without saying but in addition to configuring the SCC module using the four lines you posted, you will need to configure an SCC carrier called "SCCA" in your nidaqmxconfig file.  The KB article I linked previously includes tips on how to add that info if required.

Message Edited by Tom W [DE] on 03-05-2008 09:48 AM

[jchrisj]

Ok, I'm officially embarrased. The Save and Delete VIs are exactly where you said they were. I could have sworn that I looked at every panel in the palettes, but I obviously didn't. I did find them in the vi library out on /usr/local/natinst/ but never did find the on the palettes. Thanks!

I've got an "SCCA" carrier already defined . I've been able to see all of the analog channels on both carriers (I have two PCI-6221s, each with its own SC-2345) just not the digital channels. I'll try the "I/O Name Filtering"

thanks again,
Chris