The data interface makes it possible to uncouple the application from the CANopen stack as the communication task. This makes it possible to implement a single processor or a multi-processor system. In the latter case, the data interface is placed on a physical DPRAM:
- Command queue - the command queue is used by the control system to send requests to the application layer. This includes transmitting initialization data or requests of function components (for example to execute SDOs).
- Event queue - the event queue carries the data stream from the application layer to the control system. This data consists essentially of asynchronous confirmations (for example a response to an SDO request) and events (for example error states).
- Process image - the application acts with the CANopen network essentially by means of a process map. This map contains all I/O data and other process variables that are to be transmitted by the CANopen master.