Hamilton’s Arc-sensors can now be integrated into process control systems via Profibus DP protocol. For several years, the digital sensors for the parameters pH, ORP, conductivity and O2 (optical and amperometric) ensure a direct connection via 4…20 mA or Modbus protocol and eliminate the need for usage of a transmitter. Thanks to the digital communication between sensor and process control system, the operator is able to access not only the obligatory measuring values but also the quality relevant data like sensor and communication status, calibration data or even information concerning the measuring point which is deposited within the sensor. Within the development process, a test-series in cooperation with Sanofi-Aventis Germany took place. The Hamilton sensors, using the protocol converter, were tested on a Profibus DP Yokogawa System. As a consequence, further solutions with interfaces to Foundation Fieldbus or Profinet are possible.