TC Problem with cRIO

[Unplugnow]

I have kind of a strange problem and I suspect it is one of those instances where I am making assumptions that are not correct.

I am using LV 7.1.1 and I have a 9002 cRIO with a 9211 TC module.  All 4 channels are used and are configured (in software) as Ch0 - B-type, Ch1 - R-type, Ch2 - B-type, Ch3 - R type.  When actual B or R type thermocouples are attached to the channels of the first system they seem to read appropriately throughout their respective ranges.  However, when I inject a signal from a hand-held TC simulator, the R-type reads correctly and the B-type does not.  (for example, the B-type reads 1404F when it should read 1000F).

Another PC-based system using a TBX-1303 reads the simulated signals from the hand-held device correctly for both TC types.  Also, when one B (or R) type TC is attached to the cRIO, and another B (or R) type TC is attached to the PC-based system, and both TCs are placed in the test chamber, the temperatures track nicly all the way to the top of their ranges.

Any ideas?

[Nitin_T]

Hi Unplugnow,

Do you know what kind of voltages the TC simulator outputs. It may be putting out a voltage that is not supported by the 9211. The maximum common-mode voltage range for Channel-to-COM voltage is ±1.5 V. I would suggest going through the following KnowledgeBase. Hope this helps.