I am using an XI351002 module to read two PT100 sensors in an air cooling system.
The system consists of a fan that blows air through a radiator with cold water.
Most of the time the temperature readings work correctly, but sporadically the readings are lost and start oscillating heavily or show very high values, even though the physical temperature is stable and OK.
I have two XI351002 modules installed in the machine. When this issue occurs, if I swap the connectors, the problem follows the connector, not the module.
One test I performed: on the module where the reading is fluctuating, if I disconnect the sensor from channel 1 at the measurement point, the readings normalize for both channels. When I reconnect the sensor, the fluctuation returns.
I also measured the sensor impedance with a multimeter, and the values are normal.
After a few hours, the fluctuation disappears by itself and the readings return to normal operation.
The module does not show any diagnostic in the IO Engineering.
Has anyone seen or experienced a similar issue?