Synchronize of two USB 6211

[TheOne951]

Hello,

I would like to synchronize 2x measuring boxes USB 6211 so that I can measure with 8 AI each. I am using Labview 2023 Q1 and have tried every example in the Labview forum, but none of my DAQ starts the measurement. I would like to achieve a simultaneous measurement of both boxes by linking them to the PF. Does anyone have any suggestions or guesses why it doesn't work?

Thanks for the help in advance

[BertMcMahan]

We can't troubleshoot without seeing your code, but the basic story is you'll want to share clocks by exporting a clock from unit A into unit B. Tell B to use this external clock, and make sure to start the task on unit B *before* starting on unit A.

You'll have to do this by physically connecting a wire from your PFI clock sharing pins and a Ground terminal. You can't do it via software alone on the M series devices.

[TheOne951]

I´m not really sure how to config. the source or channel

[BertMcMahan]

Get rid of the DAQ Assistants, and try this article:

https://forums.ni.com/t5/Example-Code/DAQmx-Multidevice-Synchronization-by-Sharing-a-Sample-Clock/ta...

[santo_13]

Here is a starter code; the idea is to export the sample clock on A's PFI and use B's PFI line as a clock source (connect respective PFI on both devices).

[TheOne951]

Hi, thanks for your help, I used your Vi and wanted to measure the two inputs. on A I measure something on B nothing. I have connected the PF4 of A with PF0 of B. After 10 seconds I get the error message

Error -200284 occurred at DAQmx Multi USB M-Series Synchronization.vi

Possible cause(s):

Some or all of the requested samples have not yet been captured.
To wait until the samples are available, use a longer read timeout or read later in your program. Increase the sampling rate so that the samples are available sooner. If your task uses a start trigger, make sure that the start trigger is configured correctly. It is also possible that you have configured the task for external timing and no clock has been supplied. In this case, you must provide an external clock.

Property: RelativeTo
Corresponding value: Current read position
Property: Offset
Corresponding value: 0

Name of the task: _unnamedTask<31>