Abstract: A control panel for a fire alarm system includes a microprocessor operable to send and receive data. The microprocessor has a serial peripheral interface with a master port and a slave port. A computing device has a Differential Manchester encoder configured to encode data received from the master port and a Differential Manchester decoder configured to decode frames and send the decoded data to the slave port. A method of sending and receiving data is also disclosed.

Abstract: A system for compensating wire characteristics includes a transmission pre-emphasis module of a transmission transceiver that sends high level pre-emphasis training bits and low level pre-emphasis training bits along a wired connection, a reception pre-emphasis module of a receiver that receives the high level pre-emphasis training bits and low level pre-emphasis training bits along the wired connection, a pre-emphasis analysis module of the receiver that analyzes the high level pre-emphasis training bits and low level pre-emphasis training bits to determine a pre-emphasis level. The system further includes a controller that interfaces with the transmission transceiver and the receiver, the controller communicates the pre-emphasis level to the transmission transceiver.

Abstract: A system for compensating wire characteristics includes a transmission pre-emphasis module of a transmission transceiver that sends high level pre-emphasis training bits and low level pre-emphasis training bits along a wired connection, a reception pre-emphasis module of a receiver that receives the high level pre-emphasis training bits and low level pre-emphasis training bits along the wired connection, a pre-emphasis analysis module of the receiver that analyzes the high level pre-emphasis training bits and low level pre-emphasis training bits to determine a pre-emphasis level. The system further includes a controller that interfaces with the transmission transceiver and the receiver, the controller communicates the pre-emphasis level to the transmission transceiver.

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: An automatic addressing scheme for a life safety system having a local rail, and a plurality of modules inter-connected by the local rail, a first of the modules being a central processing unit, and the remainder being I/O modules having a variety of functions, as well as a common line forming part of the local rail; an arrangement is provided for detecting the location of each of the I/O modules and assigning addresses thereto without human intervention, the arrangement including a resistor and transistor, capable of being conductive to ground, associated with each I/O module. A constant current source is located at the central processing unit, connected by the common line to the resistors in series circuit, and with a common address input means connected from the central processing unit to said common line and thereby to the I/O modules.

Abstract: A line powered telephoe is disclosed in which the telephone is not powered from a separate external source. The improved pay telephone is powered solely by loop current available on the telephone line from the central office. A rechargeable battery is provided to store excess loop current to enable operation of the pay telephone when not off-hook to the central office. Power consumption by components of the telephone is minimized by shutting down unnecessary functions on a selective basis to ensure that sufficient excess loop current is available to recharge the battery. In addition, an improved switched-capacitor circuit is disclosed to enable storage of electricity at a voltage potential higher than the off-hook line voltage to enable firing of standard high voltage relays for coin collection and coin return.