can't add global variables into task in MAX or DAQ assistant

[Panthera395]

Hoping that some more knowledgable LV users know a solution to this problem.

We recently updated our version of DAQmx to 8.1 in an effort to solve a different problem.  However, this created a new one.  The upgrade to DAQmx 8.1 and MAX 4.0.3 seemed to go fine, but when setting up the tasks in MAX (or the DAQ assistant) the global channels aren't shown, only the physical channels tab is shown.  Existing tasks loaded from a previous configuration can still read from the global channels fine and the channels themselves test out fine. 

I attempt created a new global channel after the upgrade, but it isn't seen in the task configuration either.

I haven't tried reinstalling LV completely yet, I'd like to avoid it if possible.

Currently running:

LV 7.1

DAQmx: 8.1

Trad. Daq: 7.4.1

MAX: 4.0.3

Has anyone had a similar problem?  Any ideas on a fix?

[Sandra_T]

Hello Panthera395,

The first thing I would do in MAX is to check the virtual channels, do they appear under Data Neighborhood>>NI_DAQmx Global Virtual Channel?
If yes, what happens when you open a NI-DAQmx Task and add channels to the task. Does an additional tab appear for virtual channels?
Make sure you have the right task/channel created, for example, if you have voltage task, make sure you are adding another analog virtual channel.

I have tested this in MAX 4.1 with DAQmx 8.3 and have not seen the issue. What hardware are you using?

Regards,
  Sandra T.

Applications Engineer | National Instruments

[Panthera395]

Sandra T,

All of the virtual channels appear in the Data Neighborhood and using the "test" feature, they all read fine individually.  The existing tasks run fine, as long as you don't try to change anything.

In the create task wizard, the only tab that appears is the physical channels, the global channels does not appear at all.  I've attached a jpeg so that you can see what I am referring to.

All of the global channels are voltage channels with custom scales.  The tasks are all voltage inputs.

In terms of hardware, we are using 2 PCI-6259 cards on a computer running Windows XP.  The VI has previously run fine on this computer for the past several months.  We attempted to make some improvments to the user interface (add a front panel control for the sample rate and number of samples), but ran into some problems with the DAQ assistant.  So, we tried upgrading DAQmx to see if it fixed the problem.  Unfortunately it only created new problems.

[Sandra_T]

Hello Panthera395,

I see that you are using the PCI-6259, one of our M-series cards and LabVIEW 7.1. Is there a reason why you have not upgraded to a newer version of DAQmx. The latest driver that supports both your device as well as compatible with LabVIEW 7.1 is DAQmx 8.5. You can download the driver from the following link.

In addition, how were the virtual channels created? Did you have them imported with a .ini file? Where they created from a previous version of the DAQmx driver? Are you able to create a new virtual channel? Can you add the new DAQmx virtual channel you newly created to a task?

Regards,
  Sandra T.

Applications Engineer | National Instruments

[Panthera395]

I was able to fix the problem by reinstalling LV and installing DAQmx 8.5.  I think the main problem was that the old MAX configuration that I was using had been corrupting somehow.  Recreating the channels and tasks from scratch seems to work fine now.  Somehow the first installation of the new drivers must have had some issues during installation.