Clear-Com FIM-108 User manual

MATRIX FIBER INTERFACE
INSTRUCTION MANUAL
FIM-108

FIM-108 Matrix Fiber Interface Instruction Manual
2003 Clear-Com Intercom Systems
All Rights Reserved
Part Number 810291 Rev. A
Clear-Com Intercom Systems
4065 Hollis Street
Emeryville, CA 94608-3505
U.S.A
Clear-Com is a registered trademark of Clear-Com Intercom Systems.
The Clear-Com Logo is a registered trademark of Clear-Com Intercom Systems.

FIM-108 FIBER INTERFACE i
CONTENTS
OPERATION 1-1
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Connecting Intercom Stations to the Central Matrix. . . . . . . . . . . . . . . . . 1-2
Connecting Interface Modules to the Central Matrix . . . . . . . . . . . . . . . . 1-3
One-Fiber and Two-Fiber Configurations . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
FIM-108D Two-Fiber Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
FIM-108M and FIM-108S One-Fiber Configurations . . . . . . . . . . . . . 1-4
FIM-108 Front Panel Controls and Lights. . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Power On/Off Switch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Link Status Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Power Status Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
FIM-108 Rear Panel Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Audio and Data Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Optical Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Coaxial Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Power Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Powering an FIM-108 Unit On or Off . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
INSTALLATION 2-1
Unpacking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Installing an FIM-108 Unit in a Rack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Installing Fiber-Optic Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Connecting Fiber-Optic Cable to the FIM-108. . . . . . . . . . . . . . . . . . . . . . . 2-3
Connecting Audio/Data Cables to the FIM-108 . . . . . . . . . . . . . . . . . . . . . . 2-3
Cat-5 Cable Pinout Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Connecting Coaxial Cable to the FIM-108 . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
MAINTENANCE 3-1
Troubleshooting Tips. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Preventive Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Block Diagram of a One-Fiber System (FIM-108M or FIM-108S) . . . . . . . . 3-1
Component Layout Drawing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
GLOSSARY 4-1
SPECIFICATIONS 5-1
CLEAR-COM LIMITED WARRANTY 6-1
Factory Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Warranty Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Non-Warranty Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

FIM-108 FIBER INTERFACE 1-1
OPERATION
DESCRIPTION
With a Clear-Com FIM-108 System, you can connect Clear-Com intercom
stations or interfaces to the central matrix using fiber-optic cables at distances of
up to 12 miles (20 km). For added convenience, Clear-Com also provides BNC
connectors, so that you can connect FIM-108 units with coaxial cables at
distances of up to 1,000 feet (300 meters).
The system consists of one FIM-108 unit at the matrix-frame end and another
FIM-108 unit at the matrix-station end. Connecting the pair of interfaces with
fiber or coaxial cable, rather than with the standard 4-wire twisted copper, gives
you advantages such as increased security from electromagnetic and RF
interference, flexibility in equipment placement, ease of maintenance, and often,
reduced cost.
Clear-Com provides three versions of of the FIM-108 interface:
•AnFIM-108D interface pair connects over two single-mode fiber-optic cables
—one cable for each direction of the signal flow. You also have the option of
connecting the units with two coaxial cables, again one cable for each direction
of the signal flow.
•AnFIM-108M interface pair connects over one multimode fiber-optic cable.
The send and receive signals are combined using wave-dimension multiplexing
(WDM) so that both directions of the signal flow can transmit over one
fiber-optic cable. You also have the option of connecting the units with two
coaxial cables, one cable for each direction of the signal flow.
•AnFIM-108S interface pair connects over one single-mode fiber-optic cable.
Like the FIM-108M unit, the FIM-108S unit combines the send and receive
signals through wave-dimension multiplexing (WDM), so that both directions
of the signal flow can transmit on one fiber-optic cable. As with the other
versions, you can optionally connect the units with coaxial cable.
Table 1: Summary of FIM-108 Fiber-Optic Connection Options
NOTE: Throughout this manual the interface will be referred to generally as the
“FIM-108 interface.” The D, M, and S designations will only be used when it is
necessary to distingish between the three versions of the interface. When you see the
term “FIM-108 interface,” you can assume that the text refers generally to all versions.
INTERFACE # FIBERS FIBER MODE FIBER RANGE
FIM-108D 2singlemode
or multimode
3 miles or 5 km (multimode)
12 miles or 20 km (single mode)
FIM-108M 1 multimode 3 miles (5 km)
FIM-108S 1 single mode 12 miles (20) km
The Clear-Com FIM-108
System links up to eight
intercom stations to the
central matrix frame over
fiber optic or coaxial cable.
With fiber-optic cable, you
can place the stations at
distances of up to 12 miles
(20 km) from the central
frame.
1

FIM-108 FIBER INTERFACE
1-2
CONNECTING INTERCOM STATIONS TO THE CENTRAL MATRIX
The Clear-Com FIM-108 system transmits audio and data signals from up to eight intercom units to the matrix frame
through the process illustrated in Figure 2. For the purposes of simplification, the illustration shows only one direction
of the signal flow, while in reality the opposite direction of signal flow occurs in a a similar fashion and simultaneously,
so that the system always transmits in full-duplex mode.
Figure 1: Connecting Intercom Stations to the Central Matrix
Matrix Plus intercom stations transmit analog audio signals and digital data signals to the first FIM-108 unit via
copper cable terminated with RJ-45 connectors.
The first FIM-108 unit converts the analog audio signals to digital audio signals through an analog-to-digital
converter (ADC) located on the FIM-108 unit’s main circuit board.
The first FIM-108 unit then multiplexes (combines) the digital audio signals with the already digital data signals.
The first FIM-108 unit then converts the multiplexed digital signal into an optical signal.
The first FIM-108 unit then transmits the optical signal over up to 12 miles (20 km) of fiber-optic cable (or
1,000 ft. of coaxial cable) to the second FIM-108 unit, where a similar but reverse process occurs to convert the
signal back to its original format.
The second FIM-108 unit converts the received optical signal to a digital signal.
The second FIM-108 unit then “demultiplexes” (separates) the digital signal back into its separate audio and data
signals for each intercom unit.
The second FIM-108 unit then converts the digital audio signals for each intercom station to analog audio signals
by sending the signals through a digital-to-analog converter (DAC) located on the FIM-108 unit’s main circuit
board.
The second FIM-108 unit then transmits the analog audio and digital data signals for each intercom station to
the central matrix over copper cable terminated with RJ-45 connectors.
The central matrix receives the intercom stations’ audio and data signals in the same format in which they were
originally sent by the Matrix Plus 3 intercom stations.
Second FIM-108 unit converts received optical signal to digital signal ...
then demultiplexes (separates) the digital signal into the
separate audio and data signals for each intercom unit ...
then converts the digital-audio signals to analog-audio signals ...
The central matrix receives the intercom
stations' audio and data signals exactly
as they were originally sent.
First FIM-108 unit converts intercom audio signals to digital ...
then multiplexes digital-audio and digital-data signals into one digital signal ...
then converts multiplexed digital signal into an optical signal.
FIM-108 FIM-108
1
10
Fiber-optic cable transmits optical signal
up to 12 miles (20 km)
Intercom stations transmit
analog-audio and digital-data signals
over copper cable to the first FIM-108 unit.
2
3
4
8
7
6
5
and then transmits the analog-audio and digital-data signals
for each intercom station over copper cable to the central matrix.
9
1
2
3
4
5
6
7
8
9
10

FIM-108 FIBER INTERFACE 1-3
NOTE: There is a one-to-one correspondence between inputs and outputs at opposite
ends of the system. Audio inputs and outputs are on separate sets of eight RJ-45
connectors located on the rear panel of each IMS-108 unit. See “Rear Panel
Connectors” later in this chapter for more information.
Table 1 lists the main circuits on the FIM-108’s circuit board.
Table 2: Circuits in the FIM-108 System
CONNECTING INTERFACE MODULES TO THE CENTRAL MATRIX
With a pair of FIM-108 units you can also remotely connect Clear-Com
interface modules to the central matrix. For example, using a Clear-Com CCI-22
dual party-line interface at one end, you can connect two independent, external
2-wire party line systems to the central matrix from a distance of up to 12 miles
(20 km). Or, with a Clear-Com TEL-14 Telephone Interface Module, you can
send telephone audio to the central matrix over a secured, interference-free fiber
optic line.
Figure 2 shows a system with connected interface modules.
Figure 2: Connecting Interface Modules to the Central Matrix
CIRCUIT DESCRIPTION
Analog-to-Digital
(A/D) Converters
High speed analog-to-digital converters for each
audio channel.
Multiplexer Sequentially presents eight RS-422 digital inputs and
eight digitized audio signals from the A/D converters
to the optical output driver.
Demultiplexer Takes sequential digital signals from the pin diode
and separates them into 20 separate lines: eight to
the D/A converters, eight to the RS-422 transmitters
and four for overhead.
Digital-to-Analog
(D/A) Converters
High speed digital-to-analog converters for each
audio channel convert the digitized audio signal back
to analog audio.
FIM-108 FIM-108
CCI-22 Interface
TEL-14 Interface
Connects two 2-wire
party-line circuits
Connects 2 tele-
phone lines
EFI-M Interface
Connects 2-wire
party-line to matrix
or other 4-wire devices
WARNING: Always
use extreme caution with
fiber-optic equipment. Never
look directly into the light
port or into the end of the
optical fiber while either
FIM-108 unit is operating.
Even if you do not see visible
light, eye damage is
possible.

FIM-108 FIBER INTERFACE
1-4
ONE-FIBER AND TWO-FIBER CONFIGURATIONS
FIM-108D Two-Fiber Configuration
In a standard two-fiber system, identical FIM-108D units are used at each
location. The units both transmit at 300 nm on ST connector A and receive the
300 nm signal on ST connector B. They are connected by the two fibers so that
the optical output of each box is connected to the optical input of the other. In
both one- and two-fiber systems, the input of channel 1 on one unit becomes the
ouput of channel 1 on the other unit, and vice versa.
The two FIM-108 units in the two-fiber version are identical, so the units are
interchangeable.
FIM-108M and FIM-108S One-Fiber Configurations
In a one-fiber system, the two FIM-108 units are not identical and are configured
before shipment. They must be used as a pair. The units are connected by a single
fiber that is wavelength division multiplexed (WDM). One unit transmits from
the “A” ST connector at a wavelength of 1300 nm and also receives at 1550 nm
on the same connector. The other unit transmits from the “A” ST connector at
1550 nm and similarly receives at 1300 nm on the same connector.
The two FIM-108 units in the one-fiber versions are not identical, so if a
replacement unit is needed, the unit type must be specified.
Figure 4 illustrates the three configurations of the Clear-Com FIM-108 System.
Figure 3: Possible Optical Configurations
1300 nm
1300 nm
Unit A Unit B
Unit A Unit B
1300 nm
1550 nm
TX 1300 nm
RX 1300 nm
TX 1300 nm
RX 1550 nm
RX 1300 nm
TX 1550 nm
RX 1300 nm
TX 1300 nm
FIM-108D TWO-FIBER SYSTEM
FIM-108M ONE-FIBER SYSTEM (MULTIMODE)
Unit A Unit B
1300 nm
1550 nm
TX 1300 nm
RX 1550 nm
RX 1300 nm
TX 1550 nm
FIM-108S ONE-FIBER SYSTEM (SINGLE MODE)

FIM-108 FIBER INTERFACE 1-5
FIM-108 FRONT PANEL CONTROLS AND LIGHTS
Figure 4: Front Panel of an FIM-108 Unit
Power On/Off Switch
The power on/off switch locks to prevent inadvertent power turn off. To unlock
the switch, pull it towards you until the lock disengages. Do not try to move the
switch without first unlocking it.
Link Status Light
The link status light illuminates only when the fiber-optic link is not properly
attached, or when the the system units are not communicating properly. This
light is meaningful only if the green power light is on.
Power Status Light
The power status light illuminates when an external power supply of between 12
and 24 VDC is connected.
1
2
Power On/Off Switch
Link Status Light
3Power Status Light
1
2
3

FIM-108 FIBER INTERFACE
1-6
FIM-108 REAR PANEL CONNECTORS
Figure 5: Rear Panel of an FIM-108 Unit
Audio and Data Connectors
Eight separate pairs of RJ-45 connectors are located on an FIM-108 unit’s rear
panel as shown in Figure 5. Each pair of RJ-45 connectors attaches an audio/data
input and an audio/data ouput to the FIM-108 unit.
Optical Connectors
A high-powered LED coupled to an optical fiber generates the FIM-108 unit’s
optical output. A bulkhead-type ST connector on the FIM-108 unit’s rear panel
connects to the transmission fiber. The transmission fiber must be matched to
the fiber pigtail type specified at the time of manufacture.
The input uses a pin diode and amplifier to convert the optical signal back to an
electrical signal.
The optional single-fiber system uses a wavelength-division multiplexer to
combine and then separate the two colors used.
Coaxial Connectors
Each version of the FIM-108 unit has two BNC connectors for connecting two
75-Ohm coaxial cables.
Power Connector
A UL- and CE-listed external in-line power supply, with a 3-pin connector,
provides the required 12 VDC to operate an FIM-108 unit.
12
34
RJ-45 Audio and Data Connectors ST-type Optical Connectors
BNC Coaxial Connectors Power Connector
1
2
3
4

FIM-108 FIBER INTERFACE 1-7
POWERING AN FIM-108 UNIT ON OR OFF
With the power off at both units, check all electrical and optical connections as
described in the Installation Chapter of this manual. Firmly seat and latch all
connectors.
To power an FIM-108 unit on or off:
1. Pull the on/off lever towards you to unlock it.
The power lever locks to prevent inadvertent power turn off. When you pull
the lever towards you, the lock disengages. Never move the front-panel lever
without first unlocking it.
2. Move the lever up to turn power on, or down to turn power off.
3. Switch the power on at both FIM-108 units.
The power at both units must be on for the system to function.
4. Verify that the green power light is illuminated on each unit, and that the red
link status light is not illuminated on each unit.
If the lights do not illuminate as described, refer to the troubleshooting
section in the Maintenance Chapter for further instructions.

FIM-108 FIBER INTERFACE 2-1
INSTALLATION
UNPACKING
When you receive your Clear-Com FIM-108 System, check to make sure you
have received all components of the system. The following items make up a
Clear-Com FIM-108 System:
• Two FIM-108 multiplexer/demultiplexer units
• Two external power supplies
Inspect the units for mechanical damage. Inspect all electrical connectors for bent
or damaged pins and latches. Report any damage to the carrier and to
Clear-Com Intercom Systems.
Leave the protective plastic caps on the optical connectors until it is time to
attach the fiber(s) to the units.
INSTALLING AN FIM-108 UNIT IN A RACK
Clear-Com ships each FIM-108 unit ready for installion in an equipment rack. If
you are not installing the units in a rack, you can remove the rack adapters by
unscrewing the two #10 flat-head screws that hold each adapter in place, as
shown in Figure 1.
Figure 1: Installing or Removing the Rack Adapters
Place the FIM-108 units in their intended locations before attaching any wires or
cables. Doing so will prevent accidental damage to the cables or their connectors
during installation.
INSTALLING FIBER-OPTIC CABLE
The person installing the FIM-108 units is responsible for providing the fiber
optic cable runs. Be sure that the fiber core diameters are compatible with the
2

FIM-108 FIBER INTERFACE
2-2
intended installation distances as shown in Table 1. The factory configures the
FIM-108 units for the required fiber type before shipping.
Table 1: Maximum Fiber Lengths
Mark or tag the optical fibers when they are pulled, carefully avoiding the fiber
tip, so that their identity is known at both ends. If there is confusion about the
identity of the two fibers, shine a flashlight at one end of the fiber and look for
light at the other end.
WARNING: Do not use the FIM-108 optical output to identify cables.
Never look directly into the end of the optical fiber while either end of the
system is operating. Even if you do not see visible light, eye damage is possible.
Inspect the fiber ends and clean them with clean, dry compressed air or with
Kim-Wipes that have been saturated with isopropyl alcohol. Fingerprints or
other dirt on the optical connector end surfaces will reduce the received optical
signal level.
FIBER CORE DIAMETER MAXIMUM FIBER LENGTH
50 microns (multimode) 3 miles (5 km)
62.5 microns (multimode) 2 miles (3 km)
8 microns (single mode) 12 miles (20 km)

FIM-108 FIBER INTERFACE 2-3
CONNECTING FIBER-OPTIC CABLE TO THE FIM-108
Figure 2: ST Optical Connectors on an FIM-108 Unit’s Rear Panel
Refer to Figure 2 before connecting the optical fiber to the ST optical connectors
on the FIM-108 unit’s rear panel.
The FIM-108 is compatible with industry standard ST-type connectors.You may
use installed backbone cables or dedicated cables with it.
Always follow the connector manufacturer’s directions when fastening a
connector to the cable.
On a two-fiber system, connect the cables so that:
•transmitterSTAat one end connects to receiver ST Bat the other end, and
•transmitterSTBat one end connects to receiver ST Aat the other end.
On a one-fiber system, connect the fiber optic cable to the ST Aat each end.
Figures 3 and 4 illustrate the entire wiring scheme for the FIM-108 system.
Figure 3 illustrates the wiring for a two-fiber system (FIM-108D) and Figure 4
illustrates the wiring for a single-fiber system (FIM-108M or FIM-108S).
CONNECTING AUDIO/DATA CABLES TO THE FIM-108
RJ-45 connectors on the FIM-108 unit’s rear panel connect the unit to audio and
data inputs and outputs as shown in Figures 3 and 4. Figure 5 illustrates the
CAT-5 and above cable pinout configuration. The maximum length for CAT-5
cables is 10,000 feet (3 km).

FIM-108 FIBER INTERFACE
2-4
Figure 3: Wiring a Two-Fiber System (FIM-108D) to Intercom Stations and Interfaces with Fiber-Optic Cable
Clear-Com Matrix Rear Panel
TO MATRIX
AC - IN
90 - 245V
RELAY / GPI
J 5
PROG
J 6
SPKR OUT
J 7
LINE
HMO
J 8 J 9
EXPANSION
OUT
MIC
J 10
J 1
J 2 J 3
i-Station
Wire CAT-5 cable from matrix RJ-45 connectors to FIM-108 "matrix" RJ-45 connectors
Wire CAT-5 cable from FIM-108 "station" RJ-45 connectors to
intercom station and interface RJ-45 connectors
Matrix Port 1
Matrix Port 2
Matrix Port 3
TEL-14 Interface
CCI-22 Interface
For the two-fiber version (FIM-108D), wire fiber-optic cable from connectors "A" to "B" and "B" to "A"
AB
B
A
CC/TW
Matrix Direct
Intercom
Call Via
RS-422
Data 4-Wire
Audio
EFI-M Interface

FIM-108 FIBER INTERFACE 2-5
Figure 4: Wiring a One-Fiber System (FIM-108M or FIM-108S) to Intercom Stations and Interfaces with Fiber-Optic Cable
Clear-Com Matrix Rear Panel
TO MATRIX
AC - IN
90 - 245V
RELAY / GPI
J 5
PROG
J 6
SPKR OUT
J 7
LINE
HMO
J 8 J 9
EXPANSION
OUT
MIC
J 10
J 1
J 2 J 3
i-Station
Wire CAT-5 cable from matrix RJ-45 connectors to FIM-108 "matrix" RJ-45 connectors
Wire CAT-5 cable from FIM-108 "station" RJ-45 connectors to
intercom station and interface RJ-45 connectors
Matrix Port 1
Matrix Port 2
Matrix Port 3
TEL-14 Interface
CCI-22 Interface
For the one-fiber versions (FIM-108M and FIM-108S), wire fiber-optic cable from connectors "A" to "A"
A
A
CC/TW
Matrix Direct
Intercom
Call Via
RS-422
Data 4-Wire
Audio
EFI-M Interface

FIM-108 FIBER INTERFACE
2-6
CAT-5 CABLE PINOUT DIAGRAM
Figure 5: Cat-5 Cable Pinout Diagram
ATT-T568B (Cables wired pin-to-pin)
RJ-45 Pin Numbers
Pair 2
Pair 1
Pair 3
Pair 4
RS-422 Input +
RS-422 Input –
Audio Input +
Audio Output +
Audio Output –
Audio Input –
RS-422 Output +
RS-422 Output –
1
2
3
5
6
7
1
2
6
7
8
4
3
4
5
8
RS-422 Output +
RS-422 Output –
Audio Output +
Audio Input +
Audio Input –
Audio Output –
RS-422 Input +
RS-422 Input –
Pair 1 Audio output
Pair 2 RS-422 data input
Pair 3 Audio input
Pair 4 RS-422 data output
8765432187654321
Views from
front of
connectors
RJ-45 Pin Numbers

FIM-108 FIBER INTERFACE 2-7
CONNECTING COAXIAL CABLE TO THE FIM-108
Use 75-Ohm coaxial cable to connect to the BNC coaxial connectors. Connect
the cables so that:
• transmitter A at one end connects to receiver B at the other end, and
• transmitter B at one end connects to receiver A at the other end.
Figure 5 illustrates an FIM-108 System wired with coaxial cable.
Figure 6: Wiring the FIM-108 to Intercom Stations and Interfaces with Coaxial Cable
Clear-Com Matrix Rear Panel
TO MATRIX
AC - IN
90- 245 V
RELAY / GPI
J 5
PROG
J 6
SPKR OUT
J 7
LINE
HMO
J 8 J 9
EXPANSION
OUT
MIC
J 10
J 1
J 2 J 3
i-Station
Wire CAT-5 cable from matrix RJ-45 connectors to FIM-108 "matrix" RJ-45 connectors
Wire CAT-5 cable from FIM-108 "station" RJ-45 connectors to
intercom station and interface RJ-45 connectors
Matrix Port 1
Matrix Port 2
Matrix Port 3
TEL-14 Interface
CCI-22 Interface
Wire coaxial cable from BNC connectors "A" to "B" and "B" to "A"
AB
B
A
CC/TW
Matrix Direct
Intercom
Call Via
RS-422
Data 4-Wire
Audio
EFI-M Interface

FIM-108 FIBER INTERFACE 3-1
MAINTENANCE
TROUBLESHOOTING TIPS
Listed below are some of the more common problems that you may experience, their possible causes, and suggested
solutions.
If you are unable to resolve a problem with your FIM-108 unit, call Clear-Com Intercom Systems at [phone]
and ask for the Service Department. See the Warranty Chapter for more information.
PREVENTIVE MAINTENANCE
Every two years verify the adequacy of optical power at the far end of each optical fiber with an optical power meter.
BLOCK DIAGRAM OF A ONE-FIBER SYSTEM (FIM-108M OR FIM-108S)
Figure 1: Block Diagram for One-Fiber Systems (FIM-108M and FIM-108S)
SYMPTOM POSSIBLE CAUSE
No operation, indicators all off. No power. Make sure the power switches of
both units are on, and their
external supplies are delivering
between 12 to 24 VDC.
No operation, but front-panel
Link Status light is on.
Optical communications failure. Check for broken or
disconnected fibers. Check to see
if the FIM-108 at the other end
is operating correctly. For a
one-fiber system, check the block
diagram on page ???.
FIM-108 units are operating
correctly, but connected stations
or interfaces are not.
Check RJ-45 cables or Matrix
configuration.
LED
WDM
DET
Audio In (8)
Digital In, RS-422 (8)
Audio Out (8)
Digital Out, RS-422 (8)
LED
WDM
DET
Audio in (8)
Digital in, RS-422 (8)
Audio out (8)
Digital out, RS-422 (8)
850 nm
1300 nm
1300 nm
850 nm
Unit A Unit B
ST-type Connectors
1550 nm
1300 nm
Single Optical Fiber
3

FIM-108 FIBER INTERFACE
3-2
COMPONENT LAYOUT DRAWING
Figure 2: Component Layout Drawing of Main Circuit Board

FIM-108 FIBER INTERFACE 4-1
GLOSSARY
fiber-optic cable A fiber-optic cable consists of a glass core covered with a
reflective material called “cladding” and several layers of buffer coating to protect
the cable from the environment. A laser sends light pulses through the glass core
to the other end of the cable.
full duplex Refers to transmission of signals in two directions simultaneously.
interface A piece of electronic hardware designed to convert the 4-wire signals
of a central matrix port to some other form of communications, such as 2-wire
party line, telephone, etc. The interface is connected to a central matrix port.
The external non-4-wire device is then connected to the interface.
mode A term used to describe a light path through a fiber, as in multimode or
single mode.
multimode fiber-optic cable The glass core of a multimode fiber is larger
than the core of a single mode fiber, which causes the transmitted light beam to
disperse as it travels through the core. Single mode fiber, with its smaller core,
concentrates the light beam so that it carries signals further. Multimode fiber was
the first type of fiber offered by manufacturers. Single-mode fiber evolved as
production methods improved.
multiplexing The process by which two or more signals are transmitted over a
single communications channel. Examples include time division and wavelength
division multiplexing.
nanometer (nm) Common unit of measure for wavelength. One billionth of
a meter.
optical signal A laser at one end of a fiber-optic cable pulses on or off to send a
light signal through the glass core of the cable to the other end of the cable.
Because the light signals are binary (on or off ), the signal is digital.
port Any of the input/output connections (RJ-45 connectors) on the back panel
of the central matrix. These connectors, and the attached cables, connect the
central matrix to remote intercom devices. The term “port” emphasizes that the
connection is a “portal” between the central matrix and the remote intercom
devices.
remote station Any intelligent intercom device connected to the back-panel
ports of the central matrix. This term does not refer to devices connected
through interfaces.
single-mode fiber-optic cable The glass core of a single-mode fiber is
smaller in diameter than the core of a multimode fiber, so that the light signal
transmitted over the core is more concentrated than with multimode fiber,
which allows the signal to travel further. Single-mode fiber evolved from
multimode fiber as production methods improved.
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