In the past I used a single SCXI-1100 as a 'dumb' mux/amp by passing
the OUTPUT and AOREF lines to the front panel connector (jumpers W7
& W8), controlling the SCXI with an MIO-16, and passing the mux'ed
output to an A2000 with a BNC cable. I pulled CINs out of some
LabVIEW-supplied VIs (v2.2?) to select channel and gain. This setup
worked great and allowed me to march through a bunch of transducers
and select an appropriate gain for each one. (And allowed much faster
acquisition rates than if I did the A/D with the MIO-16.)
But now I'd like to do it with 8 SCXI-1100 modules and BNC the 8 mux'ed
signals into a pair of 6110Es..
This poses a problem, as the LabVIEW and/or NI-DAQ software effectly
turns off module 1 when I configure module 2,
turns off module 2 when
I configure module 3, etc. Not only this, but each module wants to drive
AB0+ and AB0- on the SCXIbus.
What I need is a way to set channel and gain on a module without turning
off other modules. I also need to avoid driving AB0+ and AB0- (set
AB0EN=0?). I figure the only way to do this (assuming it's possible) is
to bypass NI-DAQ and program the modules directly.
Can anybody help me out here?