Synchronizing Two DAQ devices of different types

[Tara651]

Hello,

I am new to LabVIEW and I would be grateful if you help me on this.

I am using two different DAQ devices to measure voltages and temperatures (via thermocouples). These two, have different sample rates of 1000 and 2 respectively using two separate sample clocks. I have a few problems here. First of all, I want to synchronize them but there is no physical input channel on one of the devices(NI USB 9211). Another problem is that the wait command inside the loops is not working properly and I am not able to see any data faster than one second(I am plotting a few things while taking data) although it works when I tell it to wait more than 1 second. I had both measurements in one loop and I separated them to find the cause of the problem. 

[13Cmmkl]

Hi Tara651!

This info will help you

http://www.ni.com/white-paper/4322/en/

You could optimize your program using the tips in the info to:

http://www.ni.com/gettingstarted/labviewbasics/esa/

Good Luck

[mikeporter]

The wait function is working fine. True, you are using the wrong one but it won't cause what you are seeing.

Before a loop can continue to the next iteration it has to finish everything from the current iteration. You have two things going on in parallel, the acquisition task and the timer. Because everything has to finish before continuing, the loop has to wait for both operations to complete. So the loop time will be the longest of the wait OR the acquisition. Consequently, if the acquisition is taking a second, the loop will never run faster than that no matter what you set the wait to.

Mike...