Issue Creating Analog Output DAQ Tasks

[bigjoepops]

I have a problem I was hoping you might be able to help me figure out.  I need to be able to create 6 analog output channels that will have separate data files loaded into them.  These channels will be started individually in a timed sequence.

 

I am having trouble getting the analog DAQ tasks created.  LabVIEW is complaining when I try to set them up as individual tasks in the same routine.  I used a for loop on an array of data files and an array of channel names.  The error code is suggesting that I set the channels up under one task.  But the problem with that is that I don’t know how to get individual channels of that one task started.

 

I created the initial for loop in Main.vi.  This gives me error -50103.  My single instance is in Main_1.vi.

 

I am trying to use a PXI-6363 card initially because that is all I have now.  But I will try to upgrade to a PXI-6733 when I get ready for the test.  Is there something with the 6363 that doesn't allow for multiple tasks on the same card for the same function?

 

Thanks for your help.

Joe

Main.vi

Main_1.vi

[hooovahh]

The first issue you will have is the 6363 only has 4 outputs not 6.  The second issue is this is not a simultaneous output card.  All outputs are driven by one clock, and one DAC.  So that means at best you can do is output channel 1 with one sample, then channel 2 with one sample on the next clock, then 3, then 4, then output channel 1 again with a new value.  This switching can take place very quickly, but all outputs will have one clock driving them, and the order of the output cannot be changed mid output.  The maximum output is 2.6MHz so if you go at your fastest each of the 4 channels can have a new value 650,000 times a second.

 

A much easier method is to output what you want on channel 1, and have the other 3 channels be off.  Then output what you want on channel 2 with the next outputs being off.  Of course without knowing more this may not be an option.