WO1996036139A3 - Single fiber transceiver and network - Google Patents

Abstract

A single fiber transceiver is for use in a node of a single fiber network. The transceiver repeats signals received from one node to the next node. The node may have a processor, such as a sensor or controller, connected to the transceiver for receiving signals from the network or transmitting signals onto the network. The transceiver has a receiver and associated receive data path logic and has a transmitter and associated transmission data path logic. It also has a jam detection circuit, a pulse width compensation circuit, a phase locked loop, a weak link detection circuit and an anti-recirculation timer. The jam detection circuit cuts off nodes that transmit overly long packets to prevent the remainder of the network from becoming jammed. Before a received pulse is repeated, the pulse width compensation circuit reconstitutes each data pulse from the leading edge of the pulse in order to limit degradation of the signal as it is transmitted about the network. The phase locked loop brings the received pulse closer to phase with the local clock to limit the effect of jitter on the pulse. The weak link detector detects a decrease in the received amplitude of serial data, a measure of the integrity of the fiber link. The anti-recirculation timer prevents recirculation of pulses that have already been transmitted around the network by locking out repetition of received signals for a given period after an end of packet code.