software trigger

[hrobitaille]

I would sysnchronize acquisition between systems using a ethernet link. As the AI Start vi takes a long time, I would generate a trigger signal by software to start acquisition when I receive the command throught ethernet.
I am using PXI 8175 controller (which has, on a hardware point of view, the capability to generate a trigger on the PXI bus) and PXI 6040E DAQ card.
I would avoid external connection.
Any idea (and example) are welcome.

Thanks
Hubert Robitaille

[Photon_Dan]

Synching via ethernet is not something I would recommend. There is latency and (worse) latency variation everywhere in ethernet land. The PXI chassis does have RTSI lines for triggering, but that does not get you synch between systems. I'm not sure what you mean by AI Start takes a long time. It seems pretty snappy to me.

The best method I've found to synch two systems without getting too fancy is to run a wire from the master DAQ board's SCANCLK output to the TRIG0 of the slave DAQ board in the other system. If the two DAQ boards are on the same PXI backplane, you can configure the RTSI bus to synch them very nicely.

The PXI is some high-end hardware. You might want to consider hiring an expert Alliance Member to show you its full potent
ial.

Daniel L. Press
PrimeTest Corp.
www.primetest.com