Specifications

1-2
Chapter 1
System Overview
Size and configuration
408 Base KSU
The DCS-408 system consists of the Basic Key Service Unit (KSU), 4 analog trunk circuits
and 8 station circuits. The KSU is a single cabinet, and in its basic form has 4 trunks ports
and 8 station ports: four (4) analog trunk circuits, four (4) keyset ports and four (4) single
line telephone (SLT) ports. Additionally, the KSU contains two miscellaneous ports for
general-purpose dry contact and external music source.
Two types of telephones can be connected to the system: proprietary digital stations called
“keysets” that connect to Digital Line Interface (DLI) ports and standard telephone sets,
generally called “single line telephones”, that connect to Single Line Interface (SLI) ports.
The system maximum capacity is as follows :
Analog trunk 4
Stations 8 (4 keysets, 4 SLTs)
Music channel 1 (Internal or External)
General-Purpose Dry Contact 1
SIO port 1 (RS-232C)
Technology
Memory
The systems operate using stored program control. This program is stored in EPROM
chips. All specific customer data is stored in random access memory (RAM) which is
protected against the loss of AC power to the system by an on-board battery backup system.
Microprocessor
DCS-408 uses distributed processing. The primary system processor is a 16-bit Motorola
MC68000 operating at a clock speed of 8 MHz. Secondary processing is done also in the
keysets. The digital keyset uses a Hitachi H8 processor for data communication within the
DCS-408.