Patent ID: 7570672
Filing Date: 2009-08-04
Classification: H04J

Abstract:
1. A fire alarm network fiber optic multiplex modem, comprising: plural local interfaces, a first interface of the plural local interfaces adapted to interface with data of a first data type and a second interface of the plural local interfaces adapted to interface with data of a second data type, the first data type being different from the second data type, wherein at least one of the first or second interfaces receives a signal that is unsynchronized with the fiber optic multiplex modem and wherein the signal is sampled at plural intervals within a frame cycle; a fiber optic interface; a multiplexor which combines data received at the local interfaces into an outgoing data stream, wherein a digital value is placed in the outgoing data stream based on at least one of said samples; a fiber optic modem which transmits, at a first wavelength, the outgoing data stream to the fiber optic interface and which receives, at a second wavelength, an incoming data stream via the fiber optic interface; and a demultiplexor which separates the incoming data stream into separate data streams, and which forwards each of said separate data streams to a corresponding local interface, wherein the at least one of the first or second interfaces is a digital audio interface which receives a digital audio signal that is not synchronized with the fiber optic multiplex modem, wherein the received digital audio signal is sampled at the plural intervals within the frame cycle, the digital audio value being placed in the outgoing data stream based on said samples, and wherein the digital audio value corresponds to the first sample taken during the frame cycle, a second value being placed in the outgoing data stream, said second value indicating in which of the plural samples the received digital audio signal changed values.