Thermocouples and Current Transducers will not play nice

[MattRIT]

I have a SCXI-1000 with two SCXI-1100 with SCXI-1303's on the front. I can read my 21 T-type thermocouples when the chassis has only the one SCXI-1100 cabled. If I try to cable in my other SCXI-1100 with four 4-20mA and one 0-10v transducer, the thermocouple readings go to bogus values or to NaN. Each SCXI-1100 will work on it's own, but not togeather. I have tried various positions in the chassis, jumper settings, etc. I have both set to DIFF. Ideas where to troubleshoot next?

[RIO-Todd]

When you say "when the chassis has only the one SCXI-1100 cabled" I'm assuming you that by "cabled" you mean actually putting the SCXI-1100 module into the chassis. You will only need need one SCXI-1100 module connected through a cable to a data acquisition board controlling the chassis. The other SCXI-1100 module should be configured as connected to "none."

[MattRIT]

Yes, I have only one SCXI-1100 configured as controlling the chassis. My next change was to solder 6 (NI-supplied) 249 ohm resisters into the SCXI-1100 that my 21 thermocouples are wired to. Same problem with only the one SCXI-1100 in the chassis. I think that I might be fighting a grounding problem. I am going to reduce my system to a minimum and start to recheck my connections.