DAQmx 4461How do I input to both channels at the same time

[Mr. Schapp]

I have a single NI PCI_4461 Dynamic Signal Anilizer. I'm programing in Microsoft's Visual "C++" .NET 2003 and using the DAQmx function call. My program work fine taking in 25600 data points on one of the input channels but I do not understand how to take in data into both channels on the same 4461 board at the same time.

     Thanks'

     Thomas J. Schapp

[Nathan_R]

Hi Thomas,

You can acquire from both channels using one DAQmx task. Right now you are probably using the DAQmxCreateAIVoltageChan function to add the one channel to the task. You can call this function a second time specifying the other physical channel to add the second channel to the task. Then the DAQmxReadAnalogF64 will return the data for both channels. The fillMode parameter determines if this data is interleaved or non-interleaved in the sample array. A great article on the most useful NI-DAQmx functions can be found here. Please let me know if you have any questions.

Thanks,

Message Edited by Nathan_R on 05-23-2008 02:19 PM