Siemens SCALANCE XM-400 Configuration Manual page 286

Configuring with Web Based Management
5.5 The "Layer 2" menu
● Observer
Enable or disable the observer. The "Observer" function is only available in HRP rings.
The ring port selected in the left-hand drop-down menu is connected to the "Isolated Port"
of an HRP manager.
The observer monitors malfunctions of the redundancy manager or incorrect configurations
of an HRP ring.
If the observer is enabled, it can interrupt the connected ring if errors are detected. To do
this, the observer switches a ring port to the "blocking" status. When the error is resolved,
the observer enables the port again.
● Restart Observer
If numerous errors occur in quick succession, the observer no longer enables its port
automatically. The ring port remains permanently in the "blocking" status. This is signaled
by the error LED and a message text.
After the errors have been eliminated, you can enable the port again using the "Restart
Observer" button.
Restoring factory settings
If you have restored the factory defaults, ring redundancy is disabled and the default ports are
used as the ring ports. This can lead to circulating frames and failure of the data traffic if other
settings were used in a previous configuration.
Changing over the status of the ring ports with the redundancy manager
If you configure a redundancy manager, set the status of the ring ports. With HRP the first ring
port changes to the "blocking" status and the second ring port to the "forwarding" status. As
long as ring redundancy is enabled, you cannot change the status of these ring ports.
Note
Make sure that you first open the ring so that there are no circulating frames.
Changing ring ports
You can change the ring ports without needing to open the ring.
To change the ring ports, follow the steps below:
1. Change to the page "Layer 2 > Spanning Tree > CIST Port".
2. Disable the ports in the spanning tree you want to configure as ring ports.
3. Change to the page "Layer 2 > Ring Redundancy > Ring".
4. Select the new ring ports.
5. Change the cable connections.
6. Change to the page "Layer 2 > Spanning Tree > CIST Port".
7. Enable the ports in the spanning tree that are no longer ring ports.
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SCALANCE XM-400/XR-500 Web Based Management (WBM)
Configuration Manual, 05/2017, C79000-G8976-C248-12