The CiA 408 device profile is based on the bus-independent profile framework for fluidic systems released by the VDMA nonprofit organization of German machine builders. The profile describes the functionality of inter-connectable proportional valves, hydrostatic pumps, and hydrostatic transmissions. It is also applicable to pneumatic pumps.
The finite state automaton (FSA) for both valves and drives are the same. The operation mode parameter determines how the actual values are presented. The operation mode overlay the FSA. The operation mode selected via hardware overwrites operation mode selections via serial interfaces. If this is the case, the operation mode setting via serial port causes a failure indication.
Depending on the device type only specific operation modes are selectable. For hydraulic valves, the operation modes actual value via bus and local actual value setting are important. The FSA is controlled by a control-word. The state of the device is provided in the status-word. Several configuration parameters have been specified. Also the SI unit and prefixes are configurable via the object dictionary entries.