A temperature sensing and diagnostics system having a temperature sensor for generating a temperature characteristic and a bitbus includes a field processing module and an auxiliary processing module. The field processing module is adapted for coupling to the temperature sensor and for receiving the temperature characteristic from the temperature sensor. The field processing module includes a field diagnostic component and a field communication component configured for communication over the bitbus and is adapted to generate field operating data including a temperature diagnostic parameter as a function of the temperature characteristic. The auxiliary processing module is configured for communicating with the bitbus and for receiving the field operating data and includes an auxiliary diagnostic component and an auxiliary communication component having a fieldbus interface and a gateway component. The auxiliary processing module is configured for generating auxiliary field data as a function of the field operating data and for communicating the auxiliary field data over a fieldbus.