ElmoMC CANopen DS 301 Implementation Guide - Manual (Page 114)

Chapter 14: Error Control Protocol
For node guarding and life guarding, SimplIQ digital servo drives implement the
heartbeat mechanism, as defined by CiA DS 301, version 4.0. With this process, a CAN
slave can monitor other devices to determine if they are active, according to their
periodic heartbeat messages. The CAN slave can send heartbeats to consumers, which
may want to monitor if this slave is active.
Heartbeats are sent from the moment of initialization, even if the slave state is stopped.
Object 0x1016 is a list of heartbeats that must be accepted from external devices. Failure
to accept an expected heartbeat leads to behavior described by object 0x1029 and object
0x6007 . Non-acceptance of a consumer heartbeat message at the expected time is called a
“heartbeat event,” which creates an emergency only if the relevant bit of EMCY is set to 1
(see
object 0x2F21 ). A single emergency object may be transmitted per one heartbeat
event. The heartbeat event is reset by one of the following events:
ƒ
A new heartbeat message arrives from the producer.
ƒ The heartbeat consumer time object (0x1016) is written.
SimplIQ digital servo drives use a minimal implementation of object 0x1016. The sole
heartbeat that it monitors is that of the network master. Object 0x1017 sets the period for
sending heartbeats.
A heartbeat is a single-byte message, with the following options:
Heartbeat Description
0 Boot-up
4 Stopped
5 Operational
127 Pre-operational
The COB-ID for a heartbeat message is 0x700 + Device ID. For example, a first servo drive
with the unit ID of 1 will have heartbeat COB-ID of 0x701 = 1793.
CANopen DS 301 Implementation Guide Error Control Protocol
MAN-CAN301IG (Ver. 2.1)
14-1