Patent ID: 6307891
Filing Date: 2001-10-23
Classification: H04L,H04M,Y02D

Abstract:
A method for inhibiting outputs of a telephone line isolation system for the duration of a disruption in the system, the isolation system comprising a master circuit and an isolated circuit separated by an isolation barrier, the method comprising:in the master circuit, identifying a disruptive event;sending a freeze control signal from the master circuit to the isolated circuit across the isolation barrier to initiate a freeze mode of operation;during freeze mode operation, inhibiting output of data and control signals from the isolated circuit to circuitry outside of the telephone line isolation system, the isolated circuit being uninhibited to transmit signals to circuitry outside of the telephone line isolation system during at least some normal operations;restoring synchronization and framing lock in the isolated circuit after the disruptive event occurs; and thenending freeze mode operation and resuming normal operation of the telephone line isolation system.