synchronize two usb 6289 with a counter

[Rsilva]

Hi folks! I'm trying to sync 2 USB-6289 M Series boards using a counter.

I searched the forum and have already seen the tutorials :

"M Series Synchronization with LabVIEW and NI-DAQmx - Developer Zone - National Instruments"

"Synchronizing USB Data Acquisition - From One Device to Multiple Systems - Developer Zone - National Instruments"

"Timing and Synchronization Features of NI-DAQmx - Developer Zone - National Instruments" .

However I still have some doubts (hence the post  regarding the following points:

- if i want to use the counter as trigger for both boards do I have to export it to an PFI line and connect to the other board?

- do I do the same with clock signal (export it to the other board using an PFI line) or using the same frequency for both the counters is enough? Or both?

- do I use the same value for the frequency in the counter and both clocks? Hope someone can help me out.

If possible, point to some examples or posting would be great.

Thanks in advance for the help!

Cheers!

[Olivier_L · Accepted solution]

Hi,

All the points depend on what you need to synchronize exactly.

As you probably have already read in the links you provided, you have the possibility to share either a Trigger, or a clock, or both.

Of course, the best solution is to share both.

Then, you can choose to share directly the sample clock of one board to the other (if both sample rates are the same), or to route the reference clock, then, both cards will synchronize their Sample clock (with PLL) on the same reference clock, as stated in M Series Synchronization with LabVIEW and NI-DAQmx.

How exactly do you want to use your counter?

Do you want to generate a single pulse for triggering?

Then, for synchronisation examples, there are some .zip files at the end of the links you've read.

Regards,