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Member
Dylanboy
Posts: 7
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Accepted Solution

Duplicate physical channel with virtual channel

I accidently created more than global virtual channel with one physical channel, for example:

 

physical channel  global virtual channel

a0                       vtc00

a0                       vtc01

a0                       vtc02

 

My questions are:

 

1-How do I change the virtual channel as the following:

 

physical channel  global virtual channel

a0                       vtc00

a1                       vtc01

a2                       vtc02

 

2-How do I re-name/delete the global virtual channel, when it's not in the task?

 

Thanks you for your time, Dylan

 

 

Member
Carisa_L
Posts: 88

Re: Duplicate physical channel with virtual channel

Hi Dylan,

 

 

You can change the Global Virtual Channels in the Measurement and Automation Explorer (MAX). Double click on vtc01 for example under the Data Neighborhood. In the configuration tab, click the two blue arrows for details. You can then right-click on the selection and change the physical channel. I've included a screenshot on how to do this. Hope this helps!

 

Best,

Carisa Leal

Applications Engineer
National Instruments
Member
Dylanboy
Posts: 7
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Re: Duplicate physical channel with virtual channel

Thanks you Carisa for fast response, but that not the right answer I am looking for. 

 

May be I did not make myself clear.  I attached two screenshots for example: On one screenshot, you will see bri00, bri01, bri02, bri03, bri04, bri05, bri06, bri07, bri08, bri50 on the virtual channel tab, however you won't see them display under NI-DAQmx Global Virtual Channel (second screenshot).  On the second screenshot, you only see bri00, bri01, bri02, bri03, bri04, the rest of bris do not display on here like they display on the virtual channel tab. 

 

Now I can't create the new global virtual channel under NI-DAQmx Global Virtual Channel with the name bri05, bri06, bri07, bri08, because I will get the conflict name error pop up on the screen.  How can I delete those bris in the virtual channel tab? 

 

Thanks again for your time, Dylan

Member
Carisa_L
Posts: 88

Re: Duplicate physical channel with virtual channel

Hi Dylan,

 

Can you send me a screenshot of the error you are receiving? Hopefully this will help me find the source of the problem. Thanks!

 

-Carisa

Applications Engineer
National Instruments
Member
Dylanboy
Posts: 7
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Re: Duplicate physical channel with virtual channel

Hello Carisa,

 

Attached is the screenshot of the error pop-up, please review and let me know.

 

Thanks again for your effort, Dylan

Member
Dylanboy
Posts: 7
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Re: Duplicate physical channel with virtual channel

[ Edited ]

Hello Carisa,

 

I already fixed the error on question #1 by going to labview DAQmx Create Task.vi to rename the physical channels. 

 

Now we can focus on question #2, I can see all the bri virtual channels under the "global virtual channel" list (see attachment).  Can you advise me how to delete/remove those unwanted names (bri05,bri06,bri07,bri08,bri09,bri050) from this list? I think by deleting them from here, it will fix the problem over MAX.

 

Thanks you for your time, Dylan

Member
Carisa_L
Posts: 88

Re: Duplicate physical channel with virtual channel

Hi Dylan,

 

Please try the suggestion on the following page: http://forums.ni.com/t5/LabVIEW/how-to-remove-channel-from-DAQmx-create-Task-vi/td-p/230983

 

If this does not work, you may have to clear the MAX Database: http://digital.ni.com/public.nsf/allkb/2C7480E856987FFF862573AE005AB0D9

 

Before you do that, I would recommend exporting your current MAX configuration: http://ae.natinst.com/public.nsf/web/searchinternal/0e0d3d7c4aa8903886256b29000c9d5a?OpenDocument

 

Hope this helps!

 

-Carisa

Applications Engineer
National Instruments
Member
Dylanboy
Posts: 7
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Re: Duplicate physical channel with virtual channel

Thanks Carisa,

 

I did export the config this morning and excluded those unwanted bri virtual channel out the list, after that I reset the MAX configuration.  With this task, it deleted all my present global virtual channels.  So I imported back the config file, that I saved, into "my system".  I saw the process running into completion.  However, there is a new problem now, I don't see any global virtual channels under Data Neighborhood any more.  I search for them and found they listed under the "virtual tab" support global channel. 

 

I tried to test the UUT, it tested fine without issue.  My concern now is how can I put those channels back under Data Neighborhood, because I need to perform the calibration on those channels periodly. 

 

I thought of uninstall and reinstall the DAQmx and try to import the config file again, but I think this is painful process and I may end up lose my data over this.  How can I fix this problem?  How can I perform the calibration, if I can't view those virtual channels?

 

Many thanks for your help, Dylan

Member
Carisa_L
Posts: 88

Re: Duplicate physical channel with virtual channel

Hi Dylan,

 

I'm glad we're starting to resolve the issue. Can you elaborate or send a screenshot on where you found the global virtual channels in the "virtual tab"?

 

In the meantime, hopefully this document will help: http://digital.ni.com/public.nsf/allkb/CF495BB3F80D3E2386256DCF007CA9DE?OpenDocument

 

Thanks!

 

-Carisa

Applications Engineer
National Instruments
Member
Dylanboy
Posts: 7
0 Kudos

Re: Duplicate physical channel with virtual channel

Hello Carisa,

 

I decided to go head re-install the DAQmx this evening, and re-imported the known good config file on it.  So far, all the global virtual channels are now back under the devices and interfaces branch plus all the unwanted virtual channels have been gone - yipee!!!  I also tried to run one unit through test to ensure the virutal channels are working, they look good. 

 

Finally, the problem is resolved.  I would like to say thanks you to you and Roberto Bozozlo have been spending time to help me through this. 

 

Regards, Dylan