Error control protocols

Error control protocols enable the monitoring of CANopen FD devices in a CANopen FD network. They comprise the Heartbeat- as well as the Boot-up service. The Boot-up service enables a CANopen FD master to detect that a new CANopen FD device has entered the CANopen FD network. The Heartbeat service is used to verify that all network participants are still available in a CANopen FD network and that they are still in the intended NMT FSA state. All error control protocols are mapped to the same CAN FD data frame, using CAN-ID 700h + Node-ID of the producer.

NOTE: CANopen FD does not support CAN remote frames and does therefore not support CANopen node-/life guarding.

Heartbeat protocol

The Heartbeat protocol is cyclically transmitted and informs all Heartbeat consumers about the availability of the Heartbeat producer. In addition to the availability of the Heartbeat producer, the Heartbeat protocol provides the current NMT FSA state of the Heartbeat producer. The cycle time for transmitting the Heartbeat protocol is configurable at index 1017h in the object dictionary of the producer.

Boot-up protocol

The Boot-up protocol is transmitted as the final action in NMT FSA state Initialization, prior to enter the NMT FSA state Pre-operational. The reception of this message indicates that a CANopen FD device has entered the CANopen network. The unintended reception of such a protocol during runtime either indicates a change in the network setup (e.g. due to the addition of a CANopen FD device) or is considered as sign for an error condition (e.g. erroneous power supply of related CANopen FD device). The protocol uses the same identifier as any other error control protocol, such as e.g. the Heartbeat protocol. The 1-byte data field has a fixed value of zero.