Method for operating a measuring point having a base unit and a sensor unit, wherein the latter couples via a pluggable connector coupling with the base unit; the base unit serves for energy supply of the sensor unit, for data exchange with the sensor unit and for communication with a process monitoring installation, wherein the base unit includes: A first element of the pluggable connector coupling; a first microprocessor sensor data conditioning for communication with the process monitoring installation; a first data memory for saving measuring-point-specific data; wherein the sensor unit has a primary sensor and a sensor head; the primary sensor includes a transducer, which outputs a measured variable dependent signal; wherein the sensor head includes: A circuit for conditioning the transducer signals with an A/D converter and a second microprocessor for measurement signal processing, a second data memory for sensor data; a program memory which contains a firmware; and an interface with a second element of the pluggable connector coupling; wherein a software module is transmitted from the base unit to the sensor unit and is stored in the program memory of the sensor unit, for enabling supplementary functions for primary sensor monitoring.