Comdial Dxp Plus Instructions Manual

Viewing A Typical Line Board Installation
Static Discharge
Wrist StrapLine Board
Pre-charge
Jack Power Supply
Pre-charge Port
PLUS032
Loop Start
Line Board Pre-charge Cable
For Line Board
Installation During
Power Up
Installing The Loop Start Line Board IMI89–172
Installing The Loop Start Line Board – 5 

3.0 Connecting The Telephone Lines
The line terminations on the line board are standard modular plug/jack connections. Each modular jack provides
termination for two lines. The line outside termination can be a type 66M-xx connector block or individual
6-position modular jacks.  The wiring that is routed between the outside termination and the common equipment
circuit board termination should be twisted-pair wiring.
Remember, each line board is shipped with a ferrite collar. Bundle the line cables...

Connect Line
Cable to
Outside Line
Termination Ferrite
Collar
PLUS033
Viewing A Typical Line Connection
Installing The Loop Start Line Board IMI89–172
Installing The Loop Start Line Board – 7 

3.1 Understanding The DXP Plus Logical Numbering
Because there are no dedicated station or line ports in the DXP Plus, the system uses an automatic configuration
method to logically number its stations and lines. Automatic configuration occurs after you perform a master clear
on the system.
How automatic configuration works
With automatic configuration, the system does a search for all installed station and line boards in the main and
expansion cabinets, and assigns a logical number for each provided...

4.0 Making A Power Failure Station Connection
Every loop start line board provides a tip and ring pair connected to line 1 as an emergency power failure circuit.
This power fail circuit is active during a commercial AC power failure if an external battery assembly is not
installed to provide battery back-up power to the system.  Connect an industry standard, single-line telephone to
the power failure jack and use it to provide basic communications capability until the AC power to the system is
restored....

5.0 Making An Auxiliary Equipment
Interface Connection (Busy Lead Detection)
When needed, connect an industry standard non-electronic telephone device such as a FAX machine, an
industry-standard telephone, or a data device, such as a modem, on a line ahead of the common equipment. The
system will detect an off-hook condition in the connected device and turn on the status light for the line at the
system telephones to indicate that the line is busy.
Each line board makes one auxiliary equipment connection...

Installing The Direct Inward Dialing (DID) Line Board
In The DXP Plus Digital Communications System
1.0 Understanding The DID Line Board
1.1 Describing Direct Inward Dialing Parameters
Direct inward dial (DID) lines are incoming only and are employed to reduce the number of channels between the
DXP Plus and the Central Office (CO). The number of DID lines that the system accepts is limited only by the
number of installed DID boards that you can install in the system.
Direct inward dialing allows incoming...

1.2 Understanding DID Operation
The DID line is a reverse battery, loop start, two-wire voice circuit. (The term reverse battery means that it is the
DXPPlusand not the CO that provides tip and ring supervisory battery for the loop.) The PBX supervision
battery, tone address, supervisory tones, and voice signals are transmitted across the voice pair. The line
interface at the DXPPlusprovides loop current detection, loop pulse digit collection, DTMF receivers, and a
polarity reversal circuit.
In the idle...

The system returns several different call progress signals to the CO in the interval after it receives address
signalling and before it answers. It does this within 1.5 seconds after completion of address signalling.
Line Busy Tone:This tone indicates called station is busy or already being alerted by another call.
Reorder Tone:This tone indicates that the call cannot be completed due to:
blocking or lack of equipment,
an incomplete (partial dial) address is received.
Audible Ringing Tone:This tone...

2.0 Installing Circuit Boards In The Equipment Cabinet
CAUTION
Circuit boards are susceptible to damage caused by electrostatic discharge, and you must keep this fact in
mind as you handle the circuit boards. Refer to the Comdial publication IMI01-005,Handling Of
Electrostatically Sensitive Components, for general information. Specific handling precautions are also
included in this installation instruction.
2.1 Creating A Static Safe Work Area
When servicing the common equipment cabinet at the...