Synchronize problem for DAQ cards

[joeyang]

I am trying to synchronize 4 PCI-6071 DAQ cards through cables using SCNCLK pin. I know the DAQ will send a pulse through that pin. but what is the frequency of the pulse?
Also, I would like to know how to avoid the phase delay generated by the cable. Can I synchronize the DAQs through internet, how to do that?

Thank you very much!

Sincerely

Joe yang

[RIO-Todd]

The frequency of the pulse will be whatever you program it to be. For instance, one of the PCI-6071E's will use its own internal timebase and the other three (slave devices) will synchronize off of that device's (master device) clock. So you will programmatically control the master clock and then send that clock to the other three devices.

An easy way to do this is by using the RTSI (Real-Time System Integration) bus on the PCI-6071E's. You'll notice that on the side of the PCI-6071E's there is an additional pin connector. This is for the RTSI bus. You can purchase a RTSI cable and connect the RTSI bus for each device and route the master clock to all other devices through the RTSI bus. I've included a couple of links below to documents that explain synchro
nization and the RTSI bus. I hope this helps.

How Do I Synchronize Two E-Series Data Acquisition (DAQ) Devices (For AT or PCI or DAQCards)?
http://digital.ni.com/public.nsf/websearch/6EC96C76111D2E6A86256628008071A0?OpenDocument

RTSI Bus Cables
http://sine.ni.com/apps/we/nioc.vp?cid=3544〈=US

Regards,

Todd D.
NI Applications Engineer