Comdial Dxp Plus Instructions Manual

							Pre-charge jack
Pre-charge
jack
Pre-charge
jack Universal
board slots
1 - 11
Pre-charge cable for
installation during
power up
Connect board to any
universal board slotUniversal
board slots
1 - 9
Universal
board slots
1 - 10
DO NOT install boards
in last slot on right in
lower expansion cabinet.Static discharge
wrist strap Pre-charge
jack
PLUS011A
Installing The DXPT1 Board
Installing The DXPT1 Line Board IMI89–193
Installing The DXPT1 Line Board – 11 
						

							4.1 Connecting The T1 Trunk
Terminate the end of the T1 trunk with a miniature 8-pin modular plug, and plug it into the main jack on the front
edge of the DXPT1 board.
The DXPT1 board contains a built-in CSU that protects the DXP Plus from voltage surges, provides transmission
drive up to 6,000 feet, and performs diagnostic tests for the network. Therefore, a customer-supplied CSU is not
necessary unless your customer requires this addition.
If a direct connection to a repeater is within a few hundred feet, the transmit signal from the DXPT1 board may
overdrive the repeater. Repeaters normally operate best with -7.5 to -23 dB input signals. Arrange LIU switches 2,
3, and 4 to set the transmit signal level (0 dB is default).
IMPORTANT CAUTION
To help ensure that external over-voltage surges do not damage the system, Comdial engineers suggest
that you install a properly-grounded gas discharge tube or a similar primary protection device on the T1
trunk where it enters the building. If the site includes a network interface box, verify that there is standard
lightning protection installed externally to the box on its network side. Primary protection where the cable
enters the building is necessary to prevent a fire hazard inside the building.
IMI89–193 Installing The DXPT1 Line Board
12 – Installing The DXPT1 Line Board 
						

							T1003A
Front View of Main Connector
On DXPT1 Board
No connections are allowed
to pins 7 or 8. (Issue 2 boards
ONLY.) NOTE:
1R1
RC1
ReceiveC1
Transmit
T1
T 2
3
4
5
6
7
8
Connecting The TI Trunk To The DXPT1 Circuit Board
Installing The DXPT1 Line Board IMI89–193
Installing The DXPT1 Line Board – 13 
						

							4.2 Detailing The T1 Cable Requirements
Normally, the DXPT1 board connection to a central office is via a network interface box (smart jack). The box is
usually small with an 8-pin modular telephone jack for connecting to the customer premise T1 equipment
(DXPT1). For short lengths of approximately 200 feet or less, use a standard telephone cable with an 8-pin
modular plug for connection to the DXPT1. Make straight-through connections for pins 1, 2, 4, and 5 when using
these plugs on both ends of the cable. (Do not connect Pins 7 and 8.)
When spanning distances greater than 200 feet, use a low-capacitance cable (data-grade cable) having two
twisted, solid-conductor wire pairs with shielding. The type of cable with metal shielding covering each twisted
pair provides the best immunity from electrical interference. Only connect the shielding to earth ground at one end
of the cable—do not ground the shielding at the other end of the cable.
When connecting the local DXPPlusdirectly to another DXPPlussystem, be sure to connect the transmit pair
(pins 4 and 5) of the local system to the receive pair (pins 1 and 2) of the distant system. Likewise, connect the
receive pair (pins 1 and 2) of the local system to the transmit pair (pins 4 and 5) of the distant system.
IMI89–193 Installing The DXPT1 Line Board
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							4.3 Understanding The DXP Plus Logical Numbering
Because there are no dedicated station or line ports in the DXPPlus, 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.
Installing The DXPT1 Line Board IMI89–193
Installing The DXPT1 Line Board – 15 
						

							5.0 Installing The Syncronization Card
On The Services Board
Whenever you install one or more DXPT1 boards, and the DXP Plus is receiving its timing signals from an
external source, you must install one synchronization card (DXOPT–SYN) on the services board using the
following procedure.
NOTE: Whenever you install one or more DXPT1 boards, and the DXP Plus is receiving its timing signals from
an external source, you must install one synchronization card (DXOPT–SYN) on the services board. When
you connect the system to central office (CO) lines, you must include a synchronization card, and the DXP
Plus must be controlled by CO signalling. In installations where the DXP Plus supplies the clock signal
for the distant system, there is no requirement for DXOPT–SYN cards and you do not need to perform this
procedure.
1. Switch off the DXP Plus power supply, disconnect the AC power cord from the AC outlet and disconnect the
optional battery back-up assembly from the main cabinet power supply
2. Install your static discharge wrist strap on your bare wrist; adjust it for a snug fit. Be sure that the strap is
touching bare skin and is not isolated by clothing. Connect the wrist strap cord between the wrist strap and an
AC or earth ground
3. Loosen the retaining hardware and lift the front panel away from the common equipment cabinet.
NOTE: With the common equipment in the installed position, the ground lug on the side of the cabinet is an
appropriate grounding point since it should have a heavy ground wire connected between it and a good
earth ground.
CAUTION
Do not remove or install the services board while the DXP Plus is powered-on or severe system problems
may occur.
4. Locate the services board, loosen the retaining screws, remove it from the main cabinet, place it in a static
protection bag, and transport it to the static-safe work area.
5. At the static-safe work area, with your wrist strap in place, remove the services board and the DXOPT–SYN
card (if used) from their static protection bags.
6. Refer to the illustration, and install the DXOPT–SYN card at the top position on the services board with the
supplied hardware. (Actually, you can use any of the three positions; however, other non-related option cards
require installation in the lower positions so it is best to leave these positions open for those other uses.).
7. Use the method detailed in Section 5.1 to set the strapping switches on the services board. If you wish, refer to
step 8 for details, and transport the board assembly to the cabinet installation site before you set the strapping
switches.
8. Place the services board with the newly installed DXOPT–SYN card into a static protection bag and transport
the assembly back to the main cabinet.
IMI89–193 Installing The DXPT1 Line Board
16 – Installing The DXPT1 Line Board 
						

							Installing The Synchronization Card On The Services Board
Installing The DXPT1 Line Board IMI89–193
Installing The DXPT1 Line Board – 17 
						

							5.1 Configuring The Services and Interface Boards
The DXP Plus extracts clocking information from the central office (CO) that supplies the T1 lines, and routes
this information to the DXOPT–SYN sync card. The sync card uses this clocking information to derive the
synchronizing signal for the DXPT1 board’s transmit clock signal. Therefore, the DXPT1 board’s transmit clock
is slaved to the CO supplying the T1 lines. If there is only one CO supplier, that source is the primary clock
source; however, if there are two different suppliers of T1 lines, use the more reliable T1 supplier as the primary
source and the other T1 supplier as the secondary source.
You must designate one DXPT1 board as the primary board. Choose this board from among those boards that
interface the T1 lines supplied by the primary CO supplier. Designate the primary board by placing straps on the
DXSRV–PLS services board and by setting DIP switches on the expansion cabinet interface boards.
If you system has only one CO supplier, you do not need to designate a secondary board; however, if the system
has a second CO supplier of T1 lines, you must designate one DXPT1 board as the secondary board. Choose this
board from among those boards that interface the T1 lines supplied by the second CO supplier. Designate the
secondary board by placing straps on the services board or by setting DIP switches on the expansion cabinet
interface boards.
If you designate primary and secondary boards to the system even though there is only one CO clock source, the
DXOPT–SYN card functions as though it is receiving two clock signals and lights both PRI and SEC LEDs on
the front edge of the card.
IMI89–193 Installing The DXPT1 Line Board
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							5.1.1 Summerizing the Strapping
DXPT1 Cabinet LocationServices Board Strap
PRIMARY or SECONDARY*Expansion Cabinet Interface Board
Switch Setting SWA or SWB**
Main –UNV1 A
Main–UNV2 B
Main–UNV3 C
Main–UNV4 D
Main–UNV5 E
Main–UNV6 F
Main–UNV7 G
Main–UNV8 H
Main–UNV9 I
Upper Expansion–UNV1 J or K 1
Upper Expansion–UNV2 J or K 2
Upper Expansion–UNV3 J or K 3
Upper Expansion–UNV4 J or K 4
Upper Expansion–UNV5 J or K 5
Upper Expansion–UNV6 J or K 6
Upper Expansion–UNV7 J or K 7
Upper Expansion–UNV8 J or K 8
Upper Expansion–UNV9 J or K 9
Upper Expansion–UNV10 J or K 10
Upper Expansion–UNV11 J or K 11
Lower Expansion–UNV1 L or M 1
Lower Expansion UNV2 L or M 2
Lower Expansion UNV3 L or M 3
Lower Expansion UNV4 L or M 4
Lower Expansion UNV5 L or M 5
Lower Expansion UNV6 L or M 6
Lower Expansion UNV7 L or M 7
Lower Expansion UNV8 L or M 8
Lower Expansion UNV9 L or M 9
Lower Expansion UNV10 L or M 10
* Strap PRIMARY block for primary DXPT1 and/or strap SECONDARY block for secondary DXPT1.
** Switches A and B do not designate primary or secondary—they designate the first and second DXPT1
boards installed in an expansion cabinet.
Installing The DXPT1 Line Board IMI89–193
Installing The DXPT1 Line Board – 19 
						

							5.1.2 Setting The Strapping
Configure the services and interface boards by performing the steps in the following process.
1. Install your static discharge wrist strap on your bare wrist; adjust it for a snug fit. Be sure that the strap is
touching bare skin and is not isolated by clothing. Connect the wrist strap cord between the wrist strap and an
AC or earth ground
NOTE: With the common equipment in the installed position, the ground lug on the side of the cabinet is an
appropriate grounding point since it should have a heavy ground wire connected between it and a good
earth ground.
2. Remove the services board assembly from the static protection bag.
3. Identify the main cabinet board slots where you will install the DXPT1 boards, and the primary and secondary
(if available) CO line supplier. With this knowledge, designate one DXPT1 board as primary and another
DXPT1 board as secondary by placing straps on the services board.
(a)If you install one DXPT1 board in the main cabinet, you must strap one pin-pair (A–I) on the services
board’s PRIMARY strap block. This strap designates the main cabinet slot where you installed the
DXPT1 board.
Example: If you install a DXPT1 board in universal slot two in the main cabinet, you must strap pin-pair
B on the PRIMARY strap block .
(b)If you install two or more DXPT1 boards in the main cabinet, you must designate one board as the
primary board and another as the secondary board. After you have made these designations, you must
strap one pin-pair (A–I) on the services board’s PRIMARY strap block and one pin-pair (A–I) on its
SECONDARY strap block to designate the main cabinet slots where you have installed the primary and
secondary boards.This action designates the primary clock source for the DXOPT–SYN card.
Example: If you install two DXPT1 boards in universal slots two and three in the main cabinet and you
designate these boards primary and secondary respectively, you must strap pin-pair B on the PRIMARY
strap block and strap pin-pair C on the SECONDARY strap block.
IMI89–193 Installing The DXPT1 Line Board
20 – Installing The DXPT1 Line Board