Simultaneous Analog Output from NI-DAQmx USB-6211

[LANL13]

Hello all,

Here is my problem:

I want my DAQmx (USB-6211) to simultaneously output two different waveforms. One should be output from ao0, the other from ao1. However, I keep getting "Error -50103". I cannot figure out how to get around this. I have tried doing Case 6 from this page but have been unsuccessful (I think that I am doing it wrong). Is there any guidance you could give me? I am new at LabView.

Thank you for your time,

LANL13

P.S. - I have attached a copy of my code if it helps

NI-DAQmx USB-6211.vi

[LANL13]

Sorry, I don't think that the VI posted well. Here it is again:

[Dennis_Knutson]

Did you do a search for this very common error. Your basic mistake is using two separate tasks instead of combining both channels into a single task.

[LANL13]

I agree that that is likely my problem, but I do not know how to fix it. How do I use 2 channels in a single task and then implement that task into my program?

[Dennis_Knutson]

Delete the second task and either specify all channels at once (i.e. Dev1\ai\ao0:1) or use a second Create Channel wired to the first.

[LANL13]

How do I make something like this: "Dev1\ai\ao0:1"

[Dennis_Knutson]

Sorry, it was supposed to be Dev1\ao0:1.

Just type it in. Or same basic way you made the Dev1\ao0 but instead click the browse button.

[LANL13]

So I replaced "Physical Channel X" and "Physical Channel Y" with "Physical Channel XY" which states Dev1\a0:1 like you said. This new physical channel is then wired to both Create Channels. However, I still get Error -50103. Should I be using a task instead of a Physical Channel? If so, how do I set it up?

Thanks for all of your help by the way. I truly appreciate it.

[Dennis_Knutson]

You are going to have to show your modifications. You only need a second create channel if the parameters (i.e. min and max) for it are different than the parameters of the first channel. If you have that, then each create channel function would specify it's own channel and you would not have dev1\ao0:1 anyplace. You would also wire the task out of the first create channel to the task in of the second create channel. You would then have a single clock, trigger, start, etc. function.

[Mcdan]

LANL13,

Here is a quick modification which should do what you want.  In this case I have used DAQmx Create Channel twice, because it is not clear if the two channels' Min/Max values will always be the same.

Hope that helps,

Dan