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 together and snap the collar
around the bundle to provide protection against radio frequency interference.
Detailing The Line Board Connections
Line Jack Pin Number Connection Telephone Number
11 No Connection
2 Line 8 Tip
3 Line 7 Tip
4 Line 7 Ring
5 Line 8 Ring
6 No Connection
21 No Connection
2 Line 6 Tip
3 Line 5 Tip
4 Line 5 Ring
5 Line 6 Ring
6 No Connection
31 No Connection
2 Line 4 Tip
3 Line 3 Tip
4 Line 3 Ring
5 Line 4 Ring
6 No Connection
41 No Connection
2 Auxiliary (Line 2) Tip
3 Line 1 Tip
4 Line 1 Ring
5 Line 2 Ring
6 Auxiliary (Line 2) Ring
51 No Connection
2 No connection
3 Power Fail (Line 1) Ring
4 Power Fail (lIne1 ) Tip
5 No Connection
6 No Connection
NOTE: If the system operation includes the direct inward station access (DISA) feature on a particular line,
callers that use DISA to access a trunk group and place calls (trunk to trunk calling) may experience low
audio levels on their calls due to the normal line resistance of CO lines. Low audio level is usually only
noticeable on long line loops. If signal loss is a problem at your site, try adding a line amplifier (repeater)
in the DISA line. Comdial does not recommend DISA for use on loop start lines without disconnect
supervision. While DISA will function, Comdial will not be liable for its performance under any condition
where disconnect supervision is not provided.
IMI89–172 Installing The Loop Start Line Board
6 – Installing The Loop Start Line Board 
						

							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 station and line encountered during the search.
The search begins in the main cabinet at the left-most universal slot and proceeds left to right. The search then
moves to the upper expansion cabinet where it searches left-most slot to right-most slot. The search finally moves
to the lower expansion cabinet where it again searches left-most slot to right-most slot. When automatic
configuration is finished, the system has logically numbered all station and line ports in ascending order from the
left-most slot to right-most slot throughout the entire system.
How logical number and physical location relate to one another
The logical number of a station or line corresponds to its relationship to other stations or lines in the system but is
not dependent upon the board’s placement in the cabinet. The physical location of a station or line corresponds to
the order of the system’s board slots. The main cabinet contains slots 1–9, the upper expansion cabinet contains
slots 10–20, and the lower expansion cabinet contains slots 21–30. Therefore, even if the first encountered station
board is located in slot five of the main cabinet, the system still assigns logical number one to the first station
provided by that board. During installation, you can skip slots. For example, you can install eight-line, loop start,
line boards in only slots one and 30 if you wish. In this case, slot one yields logical line numbers 1–8 and slot 30
yields logical line numbers 9–17.
Where you can place circuit boards
Each installed board requires timing circuits equal to its capacity. For example, a 16–station board requires 16
timing circuits, an eight–line loop start line board requires eight circuits, and a fully configured T1 trunk board
requires 24 timing circuits. In the DXP Plus, each universal slot provides 32 timing circuits. Because of this
timing circuit provision of each slot, you can place any station or line board at any slot location with no
restrictions.
Adding boards without renumbering
If you install or relocate a station or line board, this board does not operate until you take appropriate
programming action. If you use an available open slot for adding or relocating a board, that board’s stations or
lines assume logical numbers in sequence after the system’s last assigned logical station or line number. For
example, if the system’s last logical station number is 24, the logical numbers of the newly installed board’s
stations begin at logical number 25.
After you remove a board and delete it through programming, that board’s logical numbers are available for
reassignment. This means that you can remove a board, add or move another board, take the appropriate
programming action, and have the stations or lines of the added or relocated board assume the logical numbers
made available by the removed board. For example, if the system’s last logical number is 64 and you remove the
board providing stations with logical numbers 1–16 and delete it through programming, the stations on an added
board assume logical numbers beginning with 1 instead of 65. However, if you remove and program delete an
eight-station board and add a 16-station board, the first eight stations stations on the added board assume logical
numbers 1–8 and the last eight stations assume logical numbers 65–72.
Remember, should you master clear the system, the automatic configuration feature logically numbers all station
and line ports in ascending order from the left-most slot to right-most slot throughout the entire system. This
action renumbers those station and lines provided by boards that you have added or relocated since you last
performed the system master clear.
IMI89–172 Installing The Loop Start Line Board
8 – Installing The Loop Start Line Board 
						

							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. The bottom jack on the line board provides the power failure connection.
6
5
4
3
2
1
Typical Industry Standard
Non-Electronic Telephone(Front View Of Jack)Line Board
PLUS065
Making A Power Failure Station Connection
Installing The Loop Start Line Board IMI89–172
Installing The Loop Start Line Board – 9 
						

							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 available for use. This connection is at pins 1 and 6 of
the lines 1,2 jack and is associated with line 2 of that line board.
Charlottesville, Virginia 22901-2829
R
World Wide Web:  http://www.comdial.com/
Accredited by the Dutch Council
for Certification for certification
and registration activities.
Comdials Quality Management System Is
Certified To The ISO 9001 Standard.
6
5
4
3
2
1
Industry-Standard
Telephone Device
Such As: Fax
Machine, Model
2500 Telephone,
Modem, Etc.
(No A-Lead Control Required)
Line 1 Conn.
Line 2 Conn.
(Front View Of Jack)Line Board
PLUS066
Making A Typical Auxiliary Interface Connection
IMI89–172 Installing The Loop Start Line Board 
						

							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 CO calls to reach internal intercom extensions by direct dialing. No
attendant assistance is necessary. Since DID lines are incoming only, their direct appearance is limited to
attendant stations where busy indication may be useful.
DID operation requires a group of published directory numbers (400 maximum) provided by the CO.  These
directory numbers are incoming only and the DXP Plus translates them to the appropriate personal or group
intercom number for ringing. The lines will accept outgoing DTMF digits while the call is active to support
personal identification number dialing and similar user purposes.
The DXPPlushandles DID calls in the same manner that it handles regular intercom calls and will forward them
via a hunt list or a call forwarding scheme. An unanswered DID call that receives no answer will either continue
to ring or route to a programmed ring no-answer (RNA) destination. If there is no forwarding or the RNA routing
destination is available, the system provides no routing.
Users can place DID calls on hold; however, if they press
TAP, the system will generate an internal hookflash
signal instead of one that the CO will recognize.
The system returns a ring back signal to DID calls made to a station in the do not disturb (DND) mode of
operation.
When a DID line is disabled, the system returns an off-hook indication to the CO. This prevents the CO from
placing calls on a disabled line.
The synchronized ringing feature does not have any affect on DID calls, and the Caller ID feature is not available
on DID lines.
R
This manual has been developed by Comdial Corporation (the “Company”) and is intended for the use of its customers and service personnel. The information in this manual is subject to change
without notice. While every effort has been made to eliminate errors, the Company disclaims liability for any difficulties arising from the interpretation of the information contained herein.
The information contained herein does not purport to cover all details or variations in equipment or to provide for every possible contingency to be met in connection with installation, operation, or
maintenance. Should further information be desired, or should particular problems arise which are not covered sufficiently for the purchaser’s purposes, contact Comdial, Inside Sales Department,
Charlottesville, Virginia 22906.
Printed in U.S.A.IMI89-191.01
7/95 
						

							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 state, the loop is open at the CO end, with on-hook battery polarity maintained on the circuit by the
DXPPlus.The CO requests service from the DXPPlusby applying a resistive termination across the line tip and
ring leads.  The DXPPlusrecognizes current flow in the loop as a CO connection and prepares for the incoming
call. The CO does not send ringing since the DXPPlusgenerates it internally and sends it to the stations.
After the DXPPlusreceives all of the address digits, it will translate the digits based on the appropriate DID
block translation table and attempt to place the call to the desired station. To assure that the caller will always hear
ring back prior to the call being answered (for example, when answered by voice mail), the system delays the
station ringing until it applies ring back tone.
During station ringing, the called station will sound a distinctive ringing based on the ring code in the translation
table. If the translation table has a name for this CO digit string, the LCD of the called stations will display that
name. Otherwise, the DID block name will display followed by a portion of the CO digit string.  If there is
neither CO digit string name nor DID block name programmed, the station LCD will display just the CO digit
string.
If an incoming call is addressed to either an unassigned or an uninstalled station, the DXPPluswill route the call
to the DID block alternate extension.  If the DID Block alternate extension is unavailable, it routes the call to the
Dial 0 attendant. If the Dial 0 attendant is either unprogrammed or uninstalled, the DXPPluswill return reorder
tone to the caller.
IMI89–191 Installing The DID Line Board
2 – Installing The DID Line Board 
						

							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 indicates that the station is being alerted or that a recorded announcement will
follow. The ring back will precede the actual alerting of the station to assure that the caller always hears some
portion of the ring back tone.
When a called station answers, the DXPPlussends answer supervision to the CO by applying reverse polarity to
the line.  This polarity reversal is maintained until either the station goes on-hook or the CO opens the loop. The
DXPPlusestablishes a communication path between the line and station when it detects station answer.
The CO signals a line disconnect condition to the DXPPlusby opening the loop. When the DXPPlusdetects the
CO disconnect, it returns the line to idle polarity and changes the line from busy to idle.
The DXPPlussignals a line disconnect condition to the CO by returning the supervision battery polarity to the
on-hook state. Wink and delay start lines maintain the busy status until the DXPPlusdetects CO release. After
disconnect, the DXPPlusreturns to the idle state and is ready to process the next call.
With the Wink Start line
, the DXPPlusacknowledges that is ready to receive addressing digits from the CO by
giving a momentary reversal of polarity after it has successfully allocated the resources.
With the Delay Start line,the DXPPlusreverses polarity upon notification from the CO of the pending
incoming call, then acknowledges that is ready to receive addressing digits by returning the polarity back to the
idle state after it has successfully allocated the resources.
With the Immediate Start line,there is no acknowledgment from the DXPPlusthat it is ready. It is best to
only use this method if the system is set for pulse (rotary) dialing on the line.
Installing The DID Line Board IMI89–191
Installing The DID Line Board – 3 
						

							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 installation location, it is a good practice to place a
conductive mat in front of the cabinet area and ground the mat to a good earth ground. (The third wire ground of
the AC power line is also an acceptable grounding point.) The grounded conductive mat provides a safe static
electric discharge path.
When removing the common equipment cabinet from the installation location for servicing, it is a good practice to
prepare a static-safe work area on which to place the cabinet.
You should supply yourself with a static discharge wrist strap, and wear it every time you handle electronic circuit
boards either at the cabinet mounting location or at your work area.
IMI89–191 Installing The DID Line Board
4 – Installing The DID Line Board