Network Management:

Boot-up message now on guarding identifier

New: The boot-up message introduced by Beckhoff and others is specified vendor-independent for the first time in CANopen version 4. Instead of an emergency message without data, a guarding telegram with one data byte (0) is now sent.

Advantage: Uniform definition, the Data Length Code no longer changes at run time.

Effects of using new Bus Couplers in existing networks: Only if the boot-up message was evaluated previously.

Heartbeat is supported

New: In addition to node monitoring via guarding protocol (cyclic polling of the node state via remote frame) heartbeat is now also supported

Advantage: Reduced bus load, individual monitoring cycles can be configured, remote frames no longer required (some CAN controllers do not adequately support these).

Effects of using new Bus Couplers in existing networks: none