Sensor elements in embedded systems are usually connected via non-standardized interfaces to a micro-controller-based controller. In order to reduce the integration effort that is necessary especially in sensor-intensive applications, the CAN in Automation (CiA) international users’ and manufacturers’ group has developed a CANopen device profile (DS 404) for transducers and closed-loop controllers. The profile describes the interfaces for CAN-based sensors, actuators and PIDcontrollers. The internationally standardized CANopen protocol (EN 50325-4) provides communication services, with which the devices can exchange process data, receive configuration data, and transmit diagnosis data. The digital I/O functions correspond to a subgroup of the CANopen device profile for generic I/O modules (DS 401).