How can I collect the real-time signals and process the collected signals at the same time?

2 views (last 30 days)

zepeng liu on 13 Dec 2022

0
Link

Direct link to this question

https://nl.mathworks.com/matlabcentral/answers/1877402-how-can-i-collect-the-real-time-signals-and-process-the-collected-signals-at-the-same-time

Commented: Alvaro on 27 Dec 2022

Dear all,

I am trying to collect the time series signals from the daq device. In the meantime, I also want to periodically process the snapshot signals extracted from the collected signals for analysis.

What I have done is to use parallel computing toolbox and DSP System Toolbox to achieve this function.

First, I used one worker to collect the real-time signals and store them in the buffer (achieved).
Second, I plan to use another worker to periodically extract snapshot signals from the buffer for analysing (not achieved).

Part of my code is as follows:

spmd

switch spmdIndex

% -------------------------------------------------------------------

% Workers 1 Save the data from buffer

% -------------------------------------------------------------------

case 1

%% Create DataAcquisition Object

%Create a DataAcquisition object for the specified vendor.

d = daq("ni");

%% Set DataAcquisition Rate

% Set scan rate.

d.Rate = sampleRate;

%% Add Channels

%Add channels and set channel properties, if any.

addinput(d,"cDAQ1Mod1","ai0","Voltage");

addinput(d,"cDAQ1Mod1","ai1","Voltage");

addinput(d,"cDAQ1Mod1","ai2","Voltage");

%% write into buffer

dataBuff = dsp.AsyncBuffer(sampleRate*60) ;

for i = 1:5

n = ceil(d.Rate);

data = read(d,n);

dToB = [data.cDAQ1Mod1_ai0 data.cDAQ1Mod1_ai1 data.cDAQ1Mod1_ai2];

write(dataBuff, dToB); %write into buffer

end

dToP = read(dataBuff,i*sampleRate);

send(rQ, dToP) %send raw data to queue

%% Data processing

% -------------------------------------------------------------------

% Workers 2 Processes the data

% -------------------------------------------------------------------

case 2

pause(10)

end

I would like to ask if you have a way to use Worker 2 to extract the signal from the buffer, and Worker 2 should not suspend the data collection from Worker 1？