Specifications

CONTENTS
2.1
PART 2. HARDWARE DESCRIPTIONS
2.1 KEY SERVICE UNIT
The DCS 50si (see Figure 2–1) is a metal cabinet containing the following:
l A power supply (120 VAC) with battery backup (48VDC) connection
l Processing, switching and the system operating program
l Eight 2B + D digital keyset interfaces
l One MOH/BGM input source (switch selectable between internal chimes and external
input)
l One page output
2.2 EXPANSION CABINET
The optional expansion cabinet (see Figure 2–2) consists of a metal case containing a
backplane PCB with connectors for three expansion cards and a fourth connector for a
CADENCE (VM8A) card. The expansion cabinet is installed to the right of the basic KSU
and connects to the KSU motherboard via a ribbon cable and two pairs of wires.
2.3 SMEM2 CARD
To operate, the KSU must be equipped with an SMEM2 card to hold the system software
and customer database (see Figure 2–3). This software is stored in four EPROM chips
(2048 Kbytes of memory). All specific customer data is stored in non-volatile random
FIGURE 2–1
FIGURE 2–2