Fiber Optic Ring's Integrity Monitors - TC Communications TC2400 User Manual

Fiber Optic Ring's Integrity Monitors

Since communication between Master and Slave can be self-healed, it is necessary to monitor the ring's
integrity and generate an alarm signal once the A-Ring or B-Ring has breakage (See Figure 7). The TC2400
has two loop monitors, one for the A-Ring and one for the B-Ring. The monitoring signal originates from
the Master unit and travels along the A-Ring and B-Ring. Each Slave relays the monitoring signal to the
next unit. If the monitoring signal is not received by the Master, an alarm at the Master will be triggered.
The Alarm relay switch will be activated. In the meantime, the self-healing function is performed
automatically by the upstream and downstream Slave units, thereby maintaining the integrity of the link.
Figure 7. Fiber Optic Ring's Integrity Monitors
- 6 -
TC2400 & TC2401
Ring User's Manual
Rev. 1.7