The heartbeat protocol is a cyclically transmitted message that informs all heartbeat consumers of 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 message is configurable in the object dictionary index 1017_h.

The boot-up protocol represents a special type of an error control protocol. It is transmitted as the final action in the NMT initialization state, prior to enter the NMT pre-operational state. The reception of this message indicates that a new device has been registered in 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 new CANopen device) or is considered as a sign for an error condition (e.g., erroneous power supply of the related CANopen device). The protocol uses the same CAN 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.

In CANopen CC, guarding is an outdated method of checking whether a guarded CANopen CC device is still working in the correct NMT FSA state. As this is a service based on remote-frame transmission, the heartbeat protocol is used in new designs. In old-fashioned applications, the host controller triggers the error control information of the monitored CANopen CC devices via the CAN CC remote frame, for example. Each monitored CANopen CC device has to be triggered individually. The monitored device replies with a CAN CC data frame that indicates the current NMT FSA state.