Abstract: There is provided an audio communication system for a life safety system. The audio communication system includes an audio data line having a plurality of audio channels for transmitting audio data and a CPU for controlling the transmission of the audio data along the audio data line. An audio source module and an audio amplifier module are coupled to the audio data line. To produce an audible sound, the CPU selects a particular channel of the plurality of audio channels for transmitting the audio data and sends this selection to the audio source module. The audio source module then places one or more audio packets, corresponding to the audible sound, on the selected channel. The audio amplifier module then receives a signal from the CPU that identifies the selected channel and, thus, the audio amplifier module will know which channel to find the audio packets. The audio packets are converted and directed to speakers to produce the audible sound.

Abstract: There is provided a phone control system for a life safety network which comprises a panel arrangement, a control center module, a loop controller module, a transponder and a remote handset. The panel arrangement has a local rail for receiving a plurality of control modules and for interconnecting the control modules in which inter-module data is transmitted and received along the local rail. The control center module and the loop controller module are control modules positioned on the local rail. The control center module includes a processor, a memory portion, input keys for receiving user input, an output screen for displaying alpha-numeric text output, a central handset for communication of voice messages along a voice communication line. Similarly, the loop controller module includes a processor, a memory portion, and a data line interface for receiving and transmitting loop controller signals along a loop controller line. The transponder and remote handset are position remote from the panel arrangement.

Abstract: Circuit means for synthesizing the sound of a mechanical bell by combining the three most significant frequencies of the bell to be synthesized and modulating these with a decaying exponential control signal which is derived from a clock signal having a pulse repetition rate equal to the stroke repetition rate of the bell being synthesized. The combined and modulated signal is amplified and coupled to suitable audio distribution means. Modulation of the exponential signal can provide a tremolo effect.