how do i synchronize analog input and output on two USB daq?

[annettebeker]

Hi
I have problems synchronizing Analog Input and Analog Output on two USB daq cards: AI with USB 6210 and AO with USB 6211.
I was inspired by this example: Synchronizing USB Data acquisition: Multi-Device Synchronization. I am also confused about the "Master" and "slave" concept, and since this example doesn't use it i followed it...
Am attaching a screencap of my vi.
I am using the ttl output of an agilent 33220A function generator to trigger PFI lines on both devices (PFI3 in both cases), also monitoring the signal on the oscilloscope.
I connected PFI7(out) on  the USB 6211 device("dev2") to PFI2(in) on the USB 6210("dev3") to share the sample clock.
When running my vi, i do not get an error message but the vi gets stuck at the "Daqmx read" vi.
Thanks in advance for your help.
Annette

[annettebeker]

i set the timeout value on the "daqmx read" vi to 0 and get the "error -200284", with the explanation:
"Measurements: Some or all of the samples requested have not yet been acquired.

To wait for the samples to become available use a longer read timeout or read later in your program. To make the samples available sooner, increase the sample rate. If your task uses a start trigger,  make sure that your start trigger is configured correctly. It is also possible that you configured the task for external timing, and no clock was supplied. If this is the case, supply an external clock."
Could this be a problem in the routing of the sample clock in device3?

[ninlmartijn]

Dear Miss,

Thank you for your post on our forum. You can find a example in Labview by using the example finder; "Multi-Device Synch-Analog Input-Cont Acquisition.vi". I hope this example will help you further to solve your problem. Please find also the following document on our website; https://www.ni.com/en/support/documentation/supplemental/21/m-series-synchronization-with-labview-an...

Please don't hesitate to contact me if the example doesn't work.

Best regards,

Martijn S

NI Netherlands