DAQ multiple rates with digital output

Question

Hilton 2022-6-9

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1737490-daq-multiple-rates-with-digital-output

回答： Sivapriya Srinivasan 2023-9-7

I need to generate pulses to synchronize the DAQ board analog output with other two devices through TTLs. I am using the following code

s = daq.createSession('ni');
s.Rate = 1000;
%Add analog output channels
s.addAnalogOutputChannel('Dev1',0:1,'Voltage');
s.IsContinuous = false; 
%Add digital outputs to trigger external devices
DO1 = s.addCounterOutputChannel('Dev1',0,'PulseGeneration');
DO1.Frequency = s.Rate;
DO1.DutyCycle = 0.1;
DO2 = s.addCounterOutputChannel('Dev1',1,'PulseGeneration');
DO2.Frequency = s.Rate/100;
DO2.Frequency = s.Rate;
DO2.DutyCycle = 0.01;
s.queueOutputData([linspace(-1,1,100) linspace(-1,1,100)]); 
s.startForeground;
s.stop;
release(s);
clear s

The code runs and it performs the desired outputs, but the pulses DO1 and DO2 are not synced (as checked in a fast oscilloscope), although the analog output and DO1 are synced. I asked a colleague to write a simple "program" in labview (to output two TTLs at 1KHz and 10Hz) and we clearly observe that the two ouputs are synced, so it looks like some sort of bug in Matlab. Anyone has seen a similar issue?