Siko AG06 - Node Guarding

Communication via CAN bus
AG06 Date: 07.02.2018 Art. No. 85674 Mod. status 055/18 Page 49 of 114
The cycle time of the heartbeat telegram is set via object 1017
h
(see chapter 9.13.2:
Description of objects).
The heartbeat protocol is deactivated if the cycle time is 0.
The heartbeat protocol consists of one byte.
Identifier
Byte 1
11 Bit
Status
Table 28: Heartbeat protocol
Status = 0: 'INITIALISATION'
Status = 4: 'STOPPED'
Status = 5: 'OPERATIONAL'
Status = 127: 'PRE-OPERATIONAL'
The identifier of the heartbeat protocol is permanently set to 1792 + Node-ID and cannot be
changed.
Heartbeat telegram is sent in the NMT statuses 'OPERATIONAL', 'PRE-OPERATIONAL' or
'STOPPED'.
The heartbeat protocol is only enabled when node guarding is deactivated!
9.3.11 Node Guarding
Node-guarding or life-guarding mechanisms are available for failure monitoring of the
CANopen network. Via node guarding the nodes are monitored that can detect a failure of the
master. During guarding, the master transmits remote frames (remot transmit request,
message request telegrams) on the guarding identifiers of the nodes to be monitored. The
latter respond with the guarding message containing the current status of the slave as well as
a toggle bit which must change after each message.
The master assumes that a node error as occurred if status or toggle bits do not correspond
with those expected by the master.
Via the objects 100C
h
(Guard Time), 100D
h
(Life Time Factor) the time interval (life time) is
set within which the actuator expects a node query (RTR frame with the COB-ID 1792 + Node-
ID) by the NMT master.
The time interval 'Life time' is calculated from the cycle time 'Guard time' multiplied with the
factor 'Life Time Factor'.
The actuator State Machine switches to the 'SWITCH ON DISABLED' state if the actuator
receives no RTR frame from the master during the 'Life Time'.
By sending the first RTR frame of the master to the actuator, Node Guarding of the actuator is
activated after switching on.
Node Guarding is deactivated if the value of either object (100C
h
/ 100D
h
) is zero.
The response of the actuator to the RTR frame of the master consists of one byte of user data.
Identifier
Byte 1
11 Bit
Bit 7: Toggle Bit
Bit 6 ... 0: Status
Table 29: Node-Guarding Telegram