Chapter1 Product Overview
System Modules
1-30
Cisco Metro 1500 Series Hardware Installation Guide
78-10588-03
Modes of Operation
The RSM supports two operation modes: automatic mode and lock mode.
Automatic mode is the normal mode that enables the switching function of the
RSM. The lock mode is used for line testing and for servicing purposes.Youcan
switch between the modes by pushing the appropriate button on the RSM front
panel or by using the NEMI.
The RSM ships set to automatic mode and line A is the active line. Line B is the
backup line. By default, the RSM does not save its last setting in the event of a
power loss.
After power on, the RSM is set to automatic mode and one line is the active line
while the other line operates as backup line. The RSM permanently monitors the
availability of both line A and line B.
If line A breaks and the backup line (line B) is functioning, the RSM links the
communication to line B. After line A recovers no further switching takes place.
Line B continues to operate as the active line and line A as the backup line. The
same applies when the active line B breaks.
The RSM monitors the accessibility of the backup line. If line A breaks and if
line B is functional, the RSM links the communication to line B.
If line A is the active line and you lock the RSM to line B, the RSM checks the
accessibility of line B. If line B is functional, the RSM switches the
communication to line B and holds the communication on this line. Automatic
switching to the backup line (line A) is stopped. If line B is broken, the RSM
cannot be locked to line B.
B/T Line B transmitter
B/R Line B receiver
D Transmitter output to the BSM
M Receiver input from BSM
1. All connectors are of the MiniSC type.
Table1-7 RSM Optical Connector Descriptions (continued)
Label1Description