MATLAB: How to read from multiple modules on a compactDAQ using the DAQ Toolboox

acquisitioncompactdaqdataData Acquisition Toolboxinterfacemodulesmultiplesession

I have a compactDAQ chassis with multiple modules installed. How do I read from them simultaneously? For example, suppose I have NI compactDAQ with an analog input module(NI 9205) and a DIO/counter module (NI 9401).

Best Answer

There are two interfaces for data acquisition. The older Session interface and the new DataAcquisition interface. In either case, you just add input channels to your session/daq object for each input and module.
For example, with the Session interface:
s = daq.createSession('ni');
addAnalogInputChannel(s, 'cDAQ1Mod1', 'ai0', 'Voltage');
ch = addCounterInputChannel(s, 'cDAQ1Mod2', 'ctr0', 'EdgeCount');
% ... add more input channels as needed

ch.Terminal % examine the terminal and wire to it accordingly

s.Rate = 10;
s.DurationInSeconds = 1;
data = startForeground(s);
While for the DataAcquisition interface:
dq = daq("ni");
addinput(dq, "cDAQ1Mod1", "ai0", "Voltage");
ch = addinput(d,"cDAQ1Mod5","ctr0","EdgeCount"); 
% ... add more input channels as needed
ch.Terminal % examine the terminal and wire to it accordingly
dq.Rate = 1000;
data = read(dq, seconds(5));
For a comparison, between the interfaces, see:https://www.mathworks.com/help/releases/R2020b/daq/transition-your-code-from-session-to-dataacquisition-interface.html
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