generate signal continuesly and read onto graph

[eeyc]

hii
i have labview 8.5 and 6229 pci card

i want to generate signal and read it onto graph.

my vi's read voltge and generate signal with multiple channels on the same card- this work perfect
i build two waves to generate and used DAQmx Timing to control the frequency waves
during the output task(i am using continues Samples attribute of DAQmx Timing) my vi is reading voltage

now i want to add one more reading channel- i want to read first output channel
and put it on graph, until now i was physical bridge output channel wanted to one of my input channels
and read it like i reading the others.
i am sure there is unphysical way to do it!!

someone can help me??
there is internal way  to bridgedג these lines?

eyal

[Neal M]

Hello eyal,

I am sure you will be glad to hear that there is a way to do exactly what you are looking for.  There are internal channels that you can read,  and these include several analog output channels.  I have found that a majority of people to not know about this functionality of our devices, but I find it very helpful.  The way to access these channels are as follows:

1. Right click on your physical channel constant or control and select I/O Name Filtering...
   
   
   
   
   
2. Check the Internal Channels option
   
   
   
   
   
3. The internal channels should now be in the dropdown list for your device.  The ones you are looking for are the ao versus gnd channels (because the AO are single ended, you need to reference ground for a measurement), such as <device name>/_ao0_vs_aognd.

Please let me know if you have any questions about this!


Message Edited by Neal M on 05-14-2008 10:24 AM

[eeyc]

Thank's
but i have olredy have "reading jub"
i wont to add my internal channel to the other reading
and read it all at once(internal channel+ other physical channel)

eyal

[Dennis_Knutson]

Do what Neal said and add it to your existing physical channel list.

Message Edited by Dennis Knutson on 05-15-2008 07:26 AM

[eeyc]

Thank's for the replay

i did like you wrote to me
and got error mssage
200077
 

[eeyc]

my card
Maybe my card is dosent supports this option?!

[Dennis_Knutson]

Since you are configuring the analog out task for RSE, your board would seem to support that mode. Use dataflow to ensure that the analog out task is configured before the analog in task with your new channel and see if that makes a difference.

[Mcdan]

eeyc,

I believe the you are receiving the -200077 error because you are configuring your AI channels to be in RSE mode.  The internal channel you are trying to read (_ao0_vs_aognd) can only be read in differential mode.  To fix this, you'll need to add a second DAQmx Create Virtual Channel.vi to your VI.  Wire the task output of the first instance into the task input of the second.  Configure your regular channels through the first instance (ie... Dev1/ai0:31), and configure your internal channel through your second.  Set the terminal configuration of the second instance to be differential.

Hope this helps,

Dan