NI-9214 reading temperatures with no thermocouple connected

[dave6k]

Hello,

I have a EtherCAT 9144 chassis with NI-9214 thermocouple modules. I am using VeriStand and I have the open thermocouple detection option turned off. I have noticed that if I have the TB-9214 connected, but no thermocouples connected, I am getting what looks like normal temperature readings at about room temperature. Is this just reporting the terminal block's internal cold junction compensation reading?

[User002]

I'm not sure how this module works internally, but that makes sense.  If you think about it, a thermocouple creates a voltage related to the difference in temperatures between the junctions.  If there is no voltage, that would make it the same at both junctions, and it would make sense that it's the module temperature.  It makes sense that open thermocouple detection would be a useful feature for just this case.