synchronizing m-series and AO boards

[nickk]

I need to synchronize a PCI 6251 M series board with a PCI 6711 analog output board. Looking at examples, it seems like I'd want to use timing property nodes to route the source of the reference clock from the 6251 to the src of the ref clock for the 6711. However, Labview tells me that I can't route the ref clock or the master timebase from the 6251 (It says those properties are not supported by the device). The only clock I discovered I could route was the sample clock, but I want the 6711 board to run at a different sample rate than the 6251. The analog outputs from the two boards need to output samples at different rates, but still be closely synchronized after tens of minutes of operation. Is it possible to route some other clock between the two boards so they can be syncronized but running at different sampling rates?

Thanks!

-Nick

[WernerGobel]

Hi Nickk,

when the two boards are connected via a RTSI cable, you can route the timebase of one board to the RTSI clock line (RTSI 7) and the two boards should be synchronized.

Hope this helps!

[nickk]

Thanks for the help. This sounds like the solution I want, but I'm having trouble implementing it. Like I said, when I try to use a DAQmx Timing property node to get the source of the master timebase out of my m-series board, I get an error saying that that property is not supported by this device. Is this an incorrect way of routing the timebase of one board to the other? I'm also not sure how to make my program use the RTSI 7 line. What VIs/property nodes do I need to use to implement your solution? Is there something that needs to be done in MAX to control routing?

[sergesl]

Hey Nickk,

The first thing I would like to point you to is a wonderful tutorial that tells you all you need to know about DAQmx synchronization with the M Series.
More specifically on the tutorial, the case where E and M Series are synchronized is the one I would refer you to.
M series have reference clocks just allowing them to synchronize to external 10Mhz or 20MHz clocks. So you can export the timebase from the 6711 board to be used as the reference clock for the M series and they will be synchronized. At that point, both cards can have different sample rates, yet still be in synch.

Hope this helps...

[nickk]

Thanks Serges,

This does work--I think my problem was that I didn't realize the 6711 was an E series device since it is listed as an analog output board in a seperate category than the E series in the product listing. Now I know where to look for help, and your suggestion works.

-Nick

[sergesl]

Hello Nickk,

The 6711 is not really an E Series, but it works kind of the same way for synchronization. Just wanted to clear that out....
I am glad it worked for you...have a great weekend.