142 • CANopen
Network
Communication
WAGO-I/O-SYSTEM
750
CANopen
4.3.6 SYNC Monitoring
If the value of the communication cycle period is unequal to 0, monitoring is
made with the first arrival of a SYNC message if the bus coupler is in the
Op-
erational
status.
Failure of SYNC message:
If no SYNC message is received within the monitoring time (communication
cycle period), this is signalled by a blink code. No status change occurs. In
addition, an emergency message (Error Code: 0x8100, Error Register: 0x81,
Additional Code: 00 04 00 00 00) is sent. The failure of the SYNC message
will be displayed even if the MASTER provokes a status change.
It is only after the repeated receipt of the SYNC message in the
OPERATIONAL
status that the LEDs regain their normal operating status, and
another emergency message (Error Code: 0x0000, Error Register: 0x81, Addi-
tional Code: 00 04 00 000 0) is sent to show that the SYNC monitoring func-
tions again.
4.3.7 Node Guarding
The Node Guarding starts for the bus coupler when the first remote transmit
request message (RTR) is received on the COB ID for the Node Guarding
(0x700+Module-ID). If the bus coupler receives no corresponding message,
the Node Guarding is not monitored by the bus coupler.
In the default setting, the Node Guarding is deactivated, because a 0 is entered
in the corresponding indexes (0x100C = Guard-Time, 0x100D = Life Time
Factor).
The NMT master polls the bus coupler at regular intervals. This interval is
termed Guard-Time (Index 0x100C). The internal status of the bus coupler is
in the reply message.
On the arrival of an RTR request without the Guard Time being set, the Node
Guarding is not monitored, nevertheless the bus coupler replies with its inter-
nal status.
