Synchronizing acquisition Data with different devices CDAQ 9178 and NI USB 6009 and different rates

Hello, I need for my project to acquire three channel at different frequencies on two different devices CDAQ 9178 and NI USB 6009 using the following script:

Dev ='CDAQ2';

d1 = daq('ni');

% voltage acquisition

DevTot = [Dev,'Mod7'];

ch4= addinput(d1,DevTot,"ai0","Voltage");

d1.Rate=1000;

d2 = daq('ni');

% current acquisition

DevTot='Dev1';

ch6= addinput(d2,DevTot,"ai0","Voltage");

% current acquisition

DevTot = [Dev,'Mod5'];

ch7= addinput(d2,DevTot,"ai0","Voltage");

d2.Rate = 100;

daqDuration=10;

% %Configure the source data acquisition object to export a triggering signal on the PFI0 terminal of cDAQ2 chassis

addtrigger(d1, 'Digital', 'StartTrigger', 'cDAQ2/PFI0', 'External');

%Configure the destination data acquisition object to start acquisition when an external triggering signal is received at PFI0 terminal of Dev1 chassis

addtrigger(d2, 'Digital', 'StartTrigger', 'External', 'Dev1/PFI0');

%Configure the destination data acquisition object to start acquisition when an external triggering signal is received at PFI0 terminal of cDAQ2 chassis (different frequencies)

addtrigger(d2, 'Digital', 'StartTrigger', 'External', 'CDAQ2/PFI0');

start(d2, 'Duration', daqDuration)

while ~d2.WaitingForDigitalTrigger

pause(0.1)

end

start(d1, 'Duration', daqDuration)

%Wait until data acquisition is complete

while d1.Running || d2.Running

pause(1)

end

data1 = read(d1, 'all');

data2 = read(d2, 'all');

I'd like to ask if for the syncronization of these three channel I need only to connect the BNC terminal of the CDAQ 9178 with the port29 of the NI USB 6009 (PFI0).

Answer 1

[Rijuta]

Hi Nicolo’

I understand that you are seeking a way to synchronize data acquisition devices.

Yes, the synchronization of the data acquisition devices (NI cDAQ 9178 and NI USB 6009) can be achieved by connecting the BNC terminal of the cDAQ 9178 to the port 29 of the USB 6009. This will pass the trigger signal from the cDAQ 9178 to the USB 6009, allowing both devices to synchronize and acquire data simultaneously. Note that the PFI0 terminal on the USB 6009 must be set to receive the external trigger signal in the NI-MAX software, and the trigger signal on the cDAQ 9178 must be configured to generate a rising edge pulse.

For more information, please refer to the following documentation.