B&B Electronics 857-18111 - Manual - Manual (Page 27)

23
Fiber Optic Port Verification
As a troubleshooting aid, the fiber optic ports can be verified by placing a physical
loopback optical line on the ports and verify the LED behavior as shown:
The ACT LED will be configured to either the A or B fiber line as the active line. The
RAI LED is RED/GREEN indicating that there is something wrong at the far end of the
fiber line (in this case, the remote unit is missing). The ALARM LED is RED because
the E1 port is not connected. The STAT LED is RED when there is no fiber link but
turns GREEN when the fiber link is valid.
NOTE
The E1 ports are all sending AIS. However, with the fiber looped, it is because of
the
LOS on the E1 port. Without the fiber looped, it is because of the LOS of the
fiber port.
WARNING
An optical loopback will also loop back the Ethernet port. If the network cannot
tolerate this, remove the Ethernet port connection before connecting the fiber
loopback.