Chris,
One thing to remember when synchronizing multiple boards is that you want to have a start trigger in addition to routing the sample clock over the RTSI bus (examples are available in the Example Code Library [http://www.ni.com/devzone/dev_exchange/ex_search.htm] and the NI Example Finder). Here are two examples (the first uses Traditional NI-DAQ and the second NI-DAQmx):
1. http://sine.ni.com/apps/we/niepd_web_display.DISPLAY_EPD4?p_guid=B45EACE3E13D56A4E034080020E74861&p_node=DZ52336&p_submitted=N&p_rank=&p_answer=&p_source=External
2. From inside LabVIEW go to Help > Find Examples to bring up the NI Example Finder. Inside the NI Example Finder browse to Hardware Input and Output > DAQmx > Synchronization > Multi-Device > Multi-Device Synch - Share
d Timebase & Ext Dig Trigger.vi
Also realize that these aren't simultaneously sampling boards (S Series), so each channel sample on an individual board will be separated by a small interchannel delay. Depending on whether you are working Traditional NI-DAQ or NI-DAQmx (http://digital.ni.com/public.nsf/websearch/42484E84DA98053686256D32006E0494?OpenDocument) this interchannel delay is different.
Ames
Applications Engineering
National Instrument
