CiA® 402 series: CANopen device profile for drives and motion control

This set of profile specifications standardizes the functional behavior of controllers for servo drives, frequency inverters, and stepper motors. It also introduces several operation modes and corresponding configuration parameters. The profile description includes a finite state automaton (FSA) that defines internal and external device behavior for each state. The state of the drive determines which commands are accepted and whether high power is applied. States are changed when a control-word from the host-controller is received. They can also be changed due to internal events. The current state is indicated by the status-word. The control-word and different command values (e.g. velocity) are mapped into default RPDOs (receive process data objects). The status-word and different actual values (e.g. position) are mapped into TPDOs (transmit process data objects).

This profile has been partly internationally standardized in the IEC 61800-7 series. The original CiA 402 part 2 is now IEC 61800-7-201. It describes all functional behavior including the FSA and all process data and configuration parameters. CiA 402 part 3 contains mainly the PDO definitions, nowadays published in IEC 61800-7-301. In February 2024, CiA has released the revised versions of CiA 402 part 2 and CiA 402 part 3. The updated parts introduce 64-bit position values and some additional operation modes. It is intended to update the IEC standards according to the recent CiA 402 parts as soon as it is possible.

The CiA 402 part 3 (included in the IEC standard) specifies a set of generic default PDOs available to all drives as well as a set of specific default PDOs applicable only to a specific class of drives such as servo drives, frequency inverters or stepper motors. CiA has developed a third set of standardized PDOs optimized for easy system integration (CiA 402 part 5). CiA 402 part 4 specifies the safety parameters and dedicated SRDO (safety-related data objects) parameters as defined in EN 50325-5 (CANopen Safety). This approach is based on the Generic Safety Drive Profile from Ethercat Technology Group (ETG). The CiA 319 framework provides guidelines to simplify the implementation and configuration of devices using CANopen Safety communication services.

In October 2016, CiA has released the CiA 402-6 specifying the default 64-byte PDO usage for CANopen FD networks. The PDO sets are defined for servo drives and stepper motors (use the same set), for frequency converters as well as for multiple-axes systems.

On the one hand, CiA 402 is one of the best-specified motion control profiles. On the other hand, the multitude of optional functions and parameters limits the exchangeability of devices compliant to CiA 402. Some vendors implement only a subset of the mandatory functions and parameters, but still claim CiA 402 conformity.