X-300/X-400 Standby Observer - Siemens SCALANCE X-300 Configuration Manual

Configuration using Web Based Management and Command Line Interface
4.3 The X-300/X-400 menu
5. Confirm the configuration with "Set Values".
6. Now, you can plug in the redundant Ethernet connections.
Note
Make sure that the redundant Ethernet connections are plugged into the correct ports, in
other words, into the configured standby ports. Otherwise circulating frames will result
and lead to a loss of data traffic.
4.3.2.5

X-300/X-400 Standby Observer

Standby observer
The standby observer is an expansion of the simple redundant ring link. This is a second,
independent standby link to master and slave. The full standby-observer link consists of two
interconnected master-slave pairs as shown in the following figure:
Figure 4-20
Both master-slave pairs make sure independently that only one of the two link paths is
enabled at any one time. This prevents circulating frames.
Malfunctions are detected by each device comparing its current status with that of the linked
device.
To check whether a link is active, you must, however, query the statuses of both devices of a
link; in other words, slave and observer slave.
Enable or disable
The standby observer function is enabled in different ways:
● By device configuration on the "Standby Mask" page of the master or slave.
When the connection is established to the linked device, the observer function starts
automatically. This means that it is adequate for the function to be activated on one of the
two linked devices.
● On the linked devices "Observer Master" or "Observer Slave", the function is enabled
automatically when an observer frame is received.
78
Standby observer link in the HRP ring
Configuration Manual, 10/2014, C79000-G8976-C187-22
SCALANCE X-300 / X-400