Analog inputs on a MicroSmart controller are all reading a negative value.
TAC I/A Series
MicroSmart controllers (all versions)
Hardware issue or sensor failure
If the connected sensor is a RTD, a negative reading reflects an electrical short somewhere between the controller and the sensor. Note that a high positive reading reflects an electrical open circuit.
If the connected sensor is a 4-20 mA device, it typically reads a high positive value which reflects an electrical open circuit.