Specifications

DXP Correspondence Manual

Introducing The DXP

Services Board

The second slot is reserved for the Services board (DXSRV). The

services board houses all of the following: the master timing and

synchronization circuits for voice and data paths, the conferencing

circuitry (the DXP has twenty-six time slots dedicated for

conferencing) the digital pad for controlling audio on a per-channel

basis, and the voice and data time switches. The services board also

provides a 6-pin modular jack that serves as an input for

music-on-hold and background music as well as an output for an

external paging amplifier. The status light on the front of the board

stays on-steady to indicate normal system operation. The light goes

off or flashes to indicate system malfunction. For more information on

the Services board, see

IMI66-085.

CPU Board Assembly

The central processing unit, or CPU, board belongs in the third slot

(DXCPU-68K). The CPU board is actually an assembly containing the

main board and two additional cards. The CPU board holds the

primary processing and control circuits for the DXP system; it also

contains the master processor, the interface connector for the system

memory, two

DTh4F

receivers, and the system calendar and clock.

The CPU board has four 6-pin modular jacks that provide the interface

for two serial data devices and four relay contacts. Just as with the

services board, the status light is on-steady to indicate normal system

operation. The CPU light, however, flashes to indicate system

malfunction and is steady-off to indicate a loss of power.

Along with the printed-wire-boards that slide into the backplane, the

DXP has smaller circuit cards that mount directly onto certain

full-sized boards. We don’t use the terms “card” and “board”

interchangeably; boards mount directly into the DXP, while cards

mount onto boards. Two of these additional cards, the RAM and

Software cards, mount onto the CPU board and make up the assembly.

For more information on the CPU board, see

IMI66-085.

introducing The DXP 1