Common Equipment Description - Comdial G0408 Manual

Digital Telephone System
1.5

Common Equipment Description

The common equipment base unit is a fully electronic device. It is essentially a special purpose
computer system acting as a communications controller between central office (CO), private
branch exchange (PBX), or CENTREX supplied lines and the proprietary digital telephone
stations. The software design of the common equipment provides complete system support and
great flexibility of operation.
The system is fully digital with two usable time slots available for each station. Digital
information is computer-encoded voice transmission and control signals. After a computer
translates analog voice transmissions to digital information, the digital signals travel through
time division multiplexing (TDM) highways. The TDM highway can transmit several signals
over a single pair of wires at the same time. A system clock partitions TDM information into
time slots. A time slot is a portion of time assigned to a particular position of the system clock.
Each time a particular clock position is reached, the computer reads information associated with
that position. As the system clock goes through its cycle, the computer passes digital information
between pieces of equipment sharing time slots.
The common equipment consists of a base unit, which provides complete feature support, and
optional expansion modules for additional lines and stations. It is contained in a contemporary
metal housing designed to be inconspicuous in a modern office environment. It is engineered to
be wall or rack mounted.
1 – 8 Introducing The DSU
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