BUG?? Multi Channel Analog output Flips which channel it sends

[mike_fit]

I have a program that aquires 4 channels of analog input, sends 2 channels of analog output, and aquires 2 channels of counter input (on a seperate card)

My problem is that the analog output flips which channel it outputs on. I build an array and input my desired waveform for ao0 in the top of the build array, then I drag the build array down to make a second input and I connect my second wave to that input. I noticed some strange things on the scope. The program worked incorrectly, but repeatbly.

The analog output channels do the following

0 channel is sent for a level of zero , then for 1 data point a level of 5. this is to trigger a waveform generator to output a sin wave at 1hz, 1Vpp, 2cyc

1 channel is sent with a square wave to trigger a camera to take an image for each pulse.

Step 1: Open SLOSHTABLEV4.vi

Step 2: Run.

             Note: the pulse channel is sent on the waveform generator trigger causing the waveform to generate at each pulse
also the trigger channel ends high. at 5 volts. 
Step 3: Run simpleao.vi and set both channels to zero

Step 4 : Re run SLOSHTABLEV4.vi see that the output flips which channel it is sent on!!!

There are three forms of output,

the right one
one where the waveform trigger is camerapulse
one where the waveform trigger fires early.

[aNIta B]

Hi Mike,

      I set this up and tried out your code, but I can't see any signals switching, and I'm not entirely clear on what I'm supposed to be seeing.  I followed your instructions, and I'm using an M series PXI board for the AO and AI, and an E Series board for the Counter tasks (since it looked like you were using separate devices).  Can you please post screen shots of what you're describing, that would help a lot. Also, do you see the same behavior with an example like the Multi-Function Synch AI-AO.vi found in the Example Finder under Hardware Input and Output»DAQmx »Synchronization»Multifunction.  It'd be nice if we can reproduce this with simpler code.  Thanks!

[mike_fit]

Download the link
Extract
Watch the video

http://www.fit.edu/upload/uploads/26e5b433c30ddc50db3293ccbb6e5446.zip

[aNIta B]

hi Mike,

       Thanks so much for the video- that makes it a lot more clear.  I didn't have the chance to set this up with a scope here today, but have been taking a look at your code.  I'll try to get back to you tomorrow as to what I find out.  Thanks again, 

[mike_fit]

Is there another way to do it???  this is the last piece of the puzzle so that I can start running tests.

[aNIta B]

Hi Mike,

       Both myself and Brandon have been testing your code with an M-series card here.  To test this, I pared down the AI to channels 0:1, and simply wired AO into AI so that I could monitor what was being output.  I've attached screenshots of what I'm seeing.  What I'm still not understanding is what you're outputing for your AO.  I created an indicator for the data being outputted, and I'm observing on one line a pulse at the time=1000, but otherwise, the line stays low.  On the other line in the output, I'm seeing what looks like a 5V TTL pulse.  From your formula node, it looks like that's what you're going for.  

When I run your code, AI0 (which is reading from AO0), always stays at 0V (even when I run "simpleao.vi"), and AI1 (reading from AO1), always reads the TTL signal.  

Please let me know if there's something else I should be doing to reproduce this.

 

[mike_fit · Accepted solution]

The solution was to update the drivers!!! ughhh!