How can I change the buffer size on NI-Daq device, using session-based interface ?
7 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
Hello, I'm using the session-based interface to acquire datas from an NI-USB Daq-device. I'm processing datas during acquisition, using a listener. I would like to change the length of the events, recieved during acquisition. In this exemple, would it be possible to change the size of event.data, recieved in the function plotData ?
s = daq.createSession('ni');
addAnalogInputChannel(s,'cDAQ1Mod1', 'ai0', 'Voltage');
lh = addlistener(s,'DataAvailable', @plotData);
function plotData(src,event)
plot(event.TimeStamps, event.Data)
end
Thank you,
0 Kommentare
Antworten (1)
Shyam Sangaraju
am 24 Jul. 2014
Bearbeitet: Walter Roberson
am 8 Jul. 2019
You can use “getdata” function to acquire data of specific size. Following sample code demonstrates how to use “getdata” function:
>> ai = analoginput('nidaq','Dev1')
>> addchannel(ai,0);
>> set(ai,'SamplesAcquiredFcnCount',4)
>> set(ai,'SamplesAcquiredFcn',@mydaqcallback);
Where @mydaqcallback consists of the following code:
function mydaqcallback(obj, event)
% number of data samples to acquire
data = getdata(obj,obj.SamplesAcquiredFcnCount);
% you can execute your logic here.
Where ‘obj’ is an analog input object.
‘obj. SamplesAcquiredFcnCount’ is number of samples to extract.
‘data’ is m-by-n array, where m is the number of samples extracted and n is the number of channels contained by obj.
0 Kommentare
Siehe auch
Kategorien
Mehr zu Simultaneous and Synchronized Operations finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!