Is it possible to measure 128-ch signal with two 64-ch boards?

[ELCA]

Is it possible to construct 128-ch. EEG reader by using two 64-ch. E-series DAQ boards(6033E)?
If it is possible, How can I make a simultaneous triggering between two of the boards? Use RTSI?
In the case, What is the maximum sampling rate? (for the countinuous aquisition)

[Russell]

That's right. The RTSI bus allows you to share timing signals between DAQ boards. These timing signals can be sample clocks, triggers, or timebases. Each DAQ board will be able to sample it's channels at the maximum sample rate for the board divided by the number of channels sampled by that board. (I think you were perhaps wondering if synchronizing with another board would slow the overall bandwidth and that's not the case.) For example, the 6033E has a maximum sample rate of 100kS/s. 100kS/s / 64 channels equals approximately 1.5kS/s when scanning all 64 channels at once. With two 6033E's, you will be able to scan all 128 channels at 1.5kS/s.

If you're using LabVIEW, there is a shipping example called "Multi-Device Synch-Shared Timebase-Cont Acquisi
tion.vi"

Synchronize Two E Series Boards Using PFI or RTSI is another possible example.

I hope this helps!

Russell
Applications Engineer
National Instruments
http://www.ni.com/support

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