Hi QQS,
Yes, you should be able to synchronize your two devices. You can do it with the RTSI lines. You will need to purchase the RTSI cable from NI; the RTSI cable connects your two baords (physical cable connection inside your computer). Once you have the boards connected via the RTSI cable, you can program your boards to use it. You simply route your clock signal to the RTSI cable for the master board, and set the slave board to use the particular RTSI line as the clock. This can also be done for triggering and sample clock signals.
What version of LabVIEW are you using? Depending on the version, you may able to use DAQmx for your 6713 board. You will need LV 7.0 to use DAQmx with your 6713 board. However, your 6534 board is not yet supported in DAQmx (should be supported soon). You can have DAQmx and Traditional DAQ running simultaneoulsy if they are on differnet boards. For your particular situation, I would suggest using DAQmx for the 6713 and traditional for the 6534. Then, when the 6534 is supported in DAQmx, convert your traditional code to DAQmx for the 6534. You really want to have your code in DAQmx since it is our new (better) driver and all future boards will support it.
Please let me know if you have any further questions.
-Sal
