how to add channels

[Ulas Coskun]

Hello, I was using classical DAQ data acqusition.  Now I switch to DAQmx data acqusition.

In my old programs i use "AI Acquire Waveforms.vi" to read multiple channels and use array functions to single out all the arrays one by one to analyze.

I'm tring to built a similar  function since I could not find a ready to use one. Can you help me?

The command should do following things:

1. Add different channels (1 or more) to be ready to be feed into  DAQmx Read.vi
2. I should be able to change min and max data range (like we can set it in "Al Acquire Waveforms.vi")
3. If I get data from multiple channels, how can i seperate them?
4. How can i control how fast and how much data we obtain.

I hope the new system read the data in a paralel process when i get data from multiple channel.

As you can see, I'm very lost here, and please feel free to treat me like an idiot.

[Dennis_Knutson]

You create your channel list with the DAQmx Create Channel. The format of the list is Dev1/ai0:ai5 for example if you want continuous channels or Dev1/ai0, Dev1/ai3, Dev1/ai5 for example for non-continuous channels. The channel control/constant has a little arrow on the right side. To make it easy. click on it and select Browse if you want multiple channels. The same function has inputs for min and max. If you want different settings for different channels, use separate Create Channel functions for each or use a single one inside a for loop with an array of values outside the loop. The DAQmx Timing function sets the acquistion rate and DAQmx Read has an input for number of channels. You separate multiple channels the same way you did before. Use an Index Array function or you can use the new Split Signal function.

You should check out the information at http://zone.ni.com/devzone/cda/tut/p/id/5434 to help you get started with DAQmx. There are also a lot of shipping examples. You could also try the DAQ Assistant. After you've set up the assistant, you cna right click on it and select Open Front Panel to see the actual DAQmx functions.

[Ulas Coskun]

I will try it this soon and let you know the outcome. thanks for the reply.

[Elijah_K]

I also recommend you check out this document on transitioning from traditional daq to DAQmx:

http://zone.ni.com/devzone/cda/tut/p/id/4342