Generating and Acquiring Analog Signals simultaneously on USB-6212

[Jon L]

Hello, I'm a novice DAQ programmer trying to create (what I think is) something very simple.

I am using an NI USB-6212 and LabVIEW 8.5 trying to generate an analog pulse train while recording an analog input simultaneously.

My first question is, is this possible?

Since I am new at this I am using the DAQ assistant in LabVIEW.  I can acquire a signal, I can also generate the desired signal, but I cannot get them to operate simultaneously.

I have been succesful in getting my program to work with two USB-6212's, but I need to be able to do this with only one.

I've attached the block diagram and vi, I hope that this is an easy to answer question, even though my searching so far has left me empty handed.

Any help would be greatly appreciated!

Jon L 

[aNIta B · Accepted solution]

Hi Jon,

      Well, first of all- welcome to DAQ programming! I've taken a look at your code and have been running it with a simulated device just fine, as well I ran it with the 6251 PCI card in my computer and it also didn't get errors.  Could you post the error code you're getting?

If I could guess what your error is, I would say that you're having buffer errors because there's too much overhead in the DAQ Assistants to keep up with the data rates.  My suggestion would be to use the example called "Multi-Function Synch AI-AO.vi".  This program can be found in the NI Example Finder (go to Help»Find Examples... in LabVIEW).  It's specifically listed under Hardware Input and Output»DAQmx»Synchronization»Multi-Function.

Can you give that a try and let me know how it goes?  Thanks!

[Jon L]

Thank you aNItaB!

My code was not generating any errors, so I was not sure what the problem was.  I assume it was due to buffer error as the DAQ assistant removal has allowed me to do what I want.   Thank you very much, the synchronization examples was not where I was looking.

Jon