Optical Link With Parallel Maintenance Link for Feedback to Control Signal Strength And Remote Power On/Off
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-19
An optical link between two stations has a first fiber that carries data at a high data rate and a second fiber that carries maintenance information at a lower data rate. Each station has sending components and receiving components. The output signal that is produced by the receiving components is averaged and the average signal value is digitized and transmitted over the maintenance link and stored in a register in the other station. Control circuits adjust the power of the light emitting components according to the register value to operate at a minimum appropriate light output level. The register is monitored for a change that may signal a decrease in light output for a given power input. The maintenance link is also used for remote power on and off for individual devices or channels and for transmitting status reports.