multichannel

[burcu]

Hi,
I�m a MSc.student of Biomedical engineering. I�m trying to finish my thesis,I need your help.I have 3 different data acquision .vi s.One of them acquires respiration and the other Ecg.The last one acquires skin impedance. Every single vi runs perfectly. However I want combine three vi s as one. I want to see 3 graphs in one window.To do this I put three programme in a while loop but it didn�t work. I couldn�t see any data on the graphs.Thus, what do you recommend me to do. If you like I would send my vi s.Please help me.

[Dennis_Knutson]

Unless you have three different daq boards, you shouldn't have three separate acquisition VIs. If you are using DAQmx, use DAQmx Create Channel for all channels that you have wired up and then DAQmx Read will return the data for all them as either a 2D array of dbls or a waveform array. Traditional DAQ is similar except you use AI Config to define all of the input channels and AI Read returns the data.

[burcu]

I don't use DAQmx. I use ADAC 5500 DAQ board.My three VI is working properly. But I want to unify them as one VI.I put them in a while loop but the problem is every data coming form three different channels has different frequencies and different sample rates. Thus, I couln't see signals properly.Enclosed please find my VI.Could you please give me an advice how to achieve this.

[Dennis_Knutson]

Doesn't the Adac allow you to sample multiple channels at once? Right now you have three different sample rates but you should be able to use the fastest sample rate and read three channels at once using a single read function. You may not need to oversample the lowest frequency but there's no harm in doing so.