Installing The Loop Start Line Board
In The FX Series Digital Communications System
Introducing The Loop Start Line Board
Defining Loop Start
The line board signals for the host system to complete a line connection by sending a supervisory signal to the
host system. Typically this signal is the hookflash that occurs when a user takes a telephone off hook on the line.
The line board transmits this signal to the host system by placing a resistance across the line’s tip and ring leads to
complete a current loop. When the host system senses this resistance, it sends dial tone over the line thus giving
line service to the system.
Inventorying The Loop Start Line Boards
Listed below are the three versions of the loop start line board.
FXLST–04 interfaces four loop start central office lines
FXLST–08 interfaces eight loop start central office lines
FXLST–16 interfaces 16 loop start central office lines
Complying With Underwriters Laboratories Regulations
Per The Underwriters Laboratories regulation 1950, be aware of the following precautions when installing
telephone equipment that is to be directly connected to the telephone company network:
•
Never install telephone wiring during a lightning storm.
•
Never install telephone jacks in wet locations unless the jack is specifically designed for wet locations.
•
Never touch uninsulated telephone wires or terminals unless the telephone line has been disconnected at the
network interface.
•
Use caution when installing or modifying telephone lines.
•
Avoid using a telephone (other than a cordless type) during an electrical storm—there may be a remote risk of
electrical shock from lightning.
•
Do not use the telephone to report a gas leak in the vicinity of the leak.
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 nor 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. IMI89-266.01
3/97
Removing and Installing Circuit Boards in the Equipment Cabinet
CAUTION
Circuit boards for the FX Series system 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.
The FX Series system may include some installed circuit boards when it arrives at your site. The system consists
of two parts—the computer portion and the telephony portion. (You will find the computer portion discussed in a
separate publication and not discussed here.) In the telephony portion of the FX Series system, the equipment
cabinet provides universal slots that will accept either line or station boards.
When removing or installing circuit boards in the FX Series cabinet, you must install a static discharge wrist strap
on your bare wrist, and 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 a AC or earth ground.
Unless a circuit board has a pre-charge port on its front panel, disconnect the AC power cord from the AC service
outlet and disconnect the cable between the cabinet and any external battery back-up assembly before you remove
or install the circuit board. However, if the board does include a pre-charge port, you can connect a standard
telephone handset cord between the pre-charge port on the circuit board and the pre-charge port on the power
supply assembly and remove or install the circuit board while the system is operating.
Whenever you remove a circuit board from the cabinet, immediately place the board in a static protection bag
while you still have your wrist strap in place and properly grounded.
IMI89–266 Installing The Loop Start Line Board
2 – Removing and Installing Circuit Boards in the Equipment Cabinet
Creating a Static Safe Work Area
When removing circuit boards from an installation location for servicing, always transport them to a static-safe
work area in static protection bags. If you do not already have a static-safe work area, you can create one by
arranging a work area as detailed in the illustration.
Typical Earth
Ground
Static
Wrist
Strap
ESD Protective
Mat
ESD Protective
Mat
ESD Protective
Worksurface
Static 2
Common Point Ground
Creating a Static-Safe Work Area
Installing The Loop Start Line Board IMI89–266
Removing and Installing Circuit Boards in the Equipment Cabinet – 3
Removing and Installing Loop Start Line Boards
1. Normally you should disconnect the AC power cord from the AC outlet and disconnect the optional battery
back-up assembly from the power supply; however, when necessary, you can remove or install a line board in
an operating system. If you must do this, connect one end of a standard telephone handset coil cord to the
precharge port on the power supply. During step 5, you will connect the other end of this coil cord to the
precharge jack on the line board.
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
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.
3. Each new line board is supplied in a static protection bag for safe keeping. When you are ready to install the
line board, remove it from its static protection bag. Conversely, when you remove a line board from the
cabinet, immediately place it in a static protection bag.
4. Locate the proper board slot—on FX Series systems the loop start line boards connect to any universal slot.
5. If you are removing or installing the line board in an operating system, connect the free end of the precharge
cord that you installed in step 1 to the precharge jack on the line board.
6. If you are removing line boards from the cabinet, remove the retaining hardware, pull the boards toward you
until their board edge connectors separate from the cabinet’s backplane connection, and slide the boards free
of the cabinet.
7. To install line boards, orient them with the left and right guides in cabinet board cage. and press the boards
firmly until their board edge connectors properly mate with the connection on the cabinet’s backplane.
8. Make a final inspection to ensure that all line boards are oriented correctly and mated properly.
9. Install and tighten the supplied screws to secure the installed boards to the board cage.
10. Each line board includes a ferrite collar. Snap the ferrite collar around the cable to provide protection against
radio frequency interference.
Dedicated Auxiliary Board Slot
Dedicated CPU Board Slot
Universal Board Slots 1 through 6
(Used for Line or Station Boards)
fulbox2.cdr
Typical Circuit Board
Pre-charge Port Location
Power Supply Assembly
Pre-charge Port Location
Locating Circuit Boards
IMI89–266 Installing The Loop Start Line Board
4 – Removing and Installing Circuit Boards in the Equipment Cabinet
screws2.cdr
Locating The Board Retaining Hardware
remove.cdr
Removing And Installing Circuit Boards
Installing The Loop Start Line Board IMI89–266
Removing and Installing Circuit Boards in the Equipment Cabinet – 5
Connecting The Telephone Lines
Connections between the telephone company line termination (typically a type 66M-xx connector block) and the
loop start line boards are via 25-pair cables that connect to 50-pin male connectors on the line boards.
If spare conductors exist in the cables that you run between the line boards and the 66M-xx connector blocks, it is
a good practice to connect the spare conductors to earth ground. Doing this may help prevent the spare connectors
from inducing radio frequency and/or AC interference into the system.
Remember, you should snap a ferrite collar around each cable to provide protection against radio frequency
interference.
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.
Telephone Company
Line Termination or
Demarcation Point
(typically an
RJ21X connection)
System Termination
Type 66M-xx
Connector Block
Primary Protection Device
(Gas Discharge Tubes or
Similar Devices)
Line Board 50-Pin Connector
Route the cable to the system termination and
punch down the wiring on the 66M-xx connector block.
Snap a ferrite block around each cable.
line.cdr
Making The Line Connections
IMI89–266 Installing The Loop Start Line Board
6 – Connecting The Telephone Lines
Detailing The Line Board Connections
25-Pair Connections Line Pair Connections Line Identification
Wire Color Pair
Pin
No.
Clip
Term.
Pair Identification Line Port CO Number
White-Blue
1
26 1
Signal Path
Tip
1
Blue-White 1 2 Ring
White-Orange
2
27 3
Signal Path
Tip
2
Orange-White 2 4 Ring
White-Green
3
28 5
Signal Path
Tip
3
Green-White 3 6 Ring
White-Brown
4
29 7
Signal Path
Tip
4
Brown-White 4 8 Ring
White-Slate
5
30 9
Signal Path
Tip
5
Slate-White 5 10 Ring
Red-Blue
6
31 11
Signal Path
Tip
6
Blue-Red 6 12 Ring
Red-Orange
7
32 13
Signal Path
Tip
7
Orange-Red 7 14 Ring
Red-Green
8
33 15
Signal Path
Tip
8
Green-Red 8 16 Ring
Red-Brown
9
34 17
Signal Path
Tip
9
Brown-Red 9 18 Ring
Red-Slate
10
35 19
Signal Path
Tip
10
Slate-Red 10 20 Ring
Black-Blue
11
36 21
Signal Path
Tip
11
Blue-Black 11 22 Ring
Black-Orange
12
37 23
Signal Path
Tip
12
Orange-Black 12 24 Ring
Black-Green
13
38 25
Signal Path
Tip
13
Green-Black 13 26 Ring
Black-Brown
14
39 27
Signal Path
Tip
14
Brown-Black 14 28 Ring
Black-Slate
15
40 29
Signal Path
Tip
15
Slate-Black 15 30 Ring
Yellow-Blue
16
41 31 Signal Path Tip
16
Blue-Yellow 16 32 Ring
Yellow-Orange
17
42 33
Orange-Yellow 17 34
Yellow-Green
18
43 35
Green-Yellow 18 36
Yellow-Brown
19
44 37
Brown-Yellow 19 38
Yellow-Slate
20
45 39
Slate-Yellow 20 40
Violet-Blue
21
46 41
Blue-Violet 21 42
Violet-Orange
22
47 43
Orange-Violet 22 44
Violet-Green
23
48 45
Green-Violet 23 46
Violet-Brown
24
49 47 Aux. Equipment
Interface
Tip
Brown-Violet 24 48 Ring
Violet-Slate
25
50 49 Power Fail
Station
Tip
Slate-Violet 25 50 Ring
Be sure to ground all unused cable
pairs to minimize RF interference.
Installing The Loop Start Line Board IMI89–266
Connecting The Telephone Lines – 7
Understanding the FX Series Logical Numbering
Because there are no dedicated station or line ports in the FX Series, 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 and assigns a
logical number for each provided station and line encountered during the search. The search begins at universal
slot 1 and proceeds through universal slot 6. When automatic configuration is finished, the system has logically
numbered all station and line ports in ascending order from universal slot 1 to universal slot 6.
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 cabinet contains universal slots 1–6; therefore, even if the first
encountered line board is located in slot five, the system still assigns logical number one to the first line 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 6 if you wish. In this case, slot one yields logical line numbers 1–8 and slot six yields
logical line numbers 9–16.
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 FX Series, 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 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 universal slot 1 to universal slot 6 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.
IMI89–266 Installing The Loop Start Line Board
8 – Connecting The Telephone Lines
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. Pair 25 (pin numbers 50 and 25, clip terminals 49 and 50) on the line board connector jack provides the
power failure connection.
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Power Failure Terminals on
Line Board Connection Block
Pair 25,
Pins 50 and 25,
Clip Terminals 49 and 50
Typical Industry Standard
Non-electronic Telephone
(Power Failure Interface)
pwr_fail.cdr
Making A Power Failure Station Connection
Installing The Loop Start Line Board IMI89–266
Making A Power Failure Station Connection – 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 Pair 24 (pin
numbers 49 and 24, clip terminals 47 and 48) and is associated with line 2 of that line board.
Charlottesville, Virginia 22901-2829
R
World Wide Web: http://www.comdial.com/
CERTIFIED
ISO 9001
Accredited by the Dutch Council
for Accreditation for certification
and registration activities.
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Comdial's Quality Management System Is
Certified To The ISO 9001 Standard.
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ANSI-RAB
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Line Board Connection Block
Pair 24,
Pins 49 and 24,
Clip Terminals 47 and 48
a-lead.cdr
Industry-Standard
Telephone Device
Such As:
FAX, Modem, Model 2500 Telephone, etc.
(No A-Lead Control Required)
Making A Typical Auxiliary Interface Connection
IMI89–266 Installing The Loop Start Line Board
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