Fuji Electric FRENIC-Ace series - Node Guarding

9.2 CANopen Communication
9-43
COMMUNICATION FUNCTIONS
Chap 9
[ 2 ] Node Guarding
Node Guarding is a mechanism to detect disconnections by monitoring the guarding signals periodically sent from
the master.

For more information about detailed behavior of Node Guarding, refer to the CANopen specifications DS
301.
Do not use both Heartbeat and Node Guarding at the same time. If they are used at the same time, the
disconnection is not detected properly. To use Node Guarding, make Heartbeat invalid, that is, set Index
1016=0 and Index 1017=0 (refer to
Section 9.2.11 [ 1 ] ).
(1) Related object list
Index
(Hex)
Sub Name Description Data type Access
100C - Guard time
Guarding reception cycle setting (ms)
Default value: 0 (no operation)
UNSIGNED16 RW
100D - Life time factor
Guarding time coefficient Default value: 0
(no operation)
UNSIGNED8 RW
(2) Guard time and Life time factor
Sets the receive interval of Guarding signals from the master. If the Guarding signal can not be received over
preset receiving time, the disconnection is deemed to occur.
Set the receive interval in the equation below:
Guarding receive interval (ms) = Guard time (ms) × Life time factor
Example: Guard time=100ms, Life time factor =5:
Guarding receive interval (ms) = 100 ms × 5 = 500 ms

For information on the behavior upon the CANopen disconnection, refer to “9.2.12 Behavior upon detection
of CANopen network disconnection”.