Optelecom-nkf 9000 Series User manual

9000 Series
Installation and Operation Manual
Model 9971-C
10 Base T to High-Speed Port Interface Card
For transport of a 10 Base T Ethernet signal via the duplex
high-speed port available on selected models of Optelecom video
transmission cards
UM50314, Manual 9971-C, ECO23616, Rev. D

Table of Contents
Section Page
Safety Instructions ii
Functional Description 1
9971-C Indicator and Connector Locations 2
Set Up and Operation of the 9971-C 4
Typical Application Drawing 18
Troubleshooting 9971-C Links 18
Operation with the Network Management Software 19
Specifications 20
UM50314, Manual 9971-C, ECO23616, Rev. D

ii
The optical devices used in this equipment are Hazard Level 1M. As required by IEC60825-1, the installer is responsible for insuring that the label
depicted below is present in the restricted locations where this equipment is installed.
This assembly contains parts sensitive to damage by electrostatic discharge (ESD). Use ESD precautionary procedures when
touching, removing, or inserting parts or assemblies.
The chassis into which this unit is installed must be housed in a properly rated NEMA enclosure.
When this unit is operated in extremely elevated temperature conditions, it is possible for internal and external metal surfaces to
become extremely hot. Care should be taken to insure this unit is installed in a restricted area where only properly trained service
personnel have access to the unit.
Safety Instructions RM-3
This product may be electrically connected to products containing Class 1M lasers or LEDs.
• Class 1M laser product according to IEC60825-1:1993+A1+A2
•CAUTION: Use of controls or adjustments or procedures other than those specified herein may result in hazardous
radiation exposure.
• Precautions should be taken to prevent exposure to optical radiation when the unit is removed from its enclosure or when
the fiber is disconnected from the unit.
• Laser radiation may be present on a fiber connection to this unit even when the power has been removed from the unit.
• This unit is intended for installation in locations where only trained service personnel have access to the fiber connections.
• The locations of all optical connections are listed in the Connection Locations and Function section of this manual.
• Optical outputs and wavelengths are listed in the Specifications section of this manual.
The safety information contained in this section, and on other pages of this manual, must be observed whenever this unit is operated,
serviced, or repaired. Failure to comply with any precaution, warning, or instruction noted in the manual is in violation of the standards
of design, manufacture, and intended use of the unit. Optelecom-NKF assumes no liability for the customer’s failure to comply with any
of these safety requirements.
Hazard Level 1M The border shall be black and the
background shall be yellow.
LASER RADIATION
DO NOT VIEW DIRECTLY WITH OPTICAL INSTRUMENTS (MAGNIFIERS).
CLASS 1M LASER PRODUCT
CAUTION:
DISCONNECTED OPTICAL CONNECTORS MAY EMIT OPTICAL ENERGY.
DO NOT VIEW BEAM WITH OPTICAL INSTRUMENTS (MAGNIFIERS).

iii
Los dispositivos ópticos usados en este equipo son de Nivel de Riesgo 1M. Según lo exige la norma IEC60825-1, el instalador es responsable de
asegurar que la etiqueta descrita a continuación esté presente en las ubicaciones restringidas donde se instale este equipo.
Este ensamblaje contiene piezas sensibles al daño por descargas electrostáticas (ESD, por sus siglas en inglés). Use
procedimientos para prevenir las descargas electrostáticas al tocar, desmontar o insertar piezas o ensamblajes.
El chasis en el cual está instalada esta unidad debe estar dentro de un alojamiento debidamente calificado por NEMA.
Cuando se opera esta unidad en condiciones de temperatura sumamente elevada, es posible que las superficies internas y
externas de metal se pongan extremadamente calientes. Debe tenerse cuidado para asegurar que esta unidad se instale en un
área restringida donde sólo tenga acceso a la unidad el personal de servicio debidamente capacitado.
Instrucciones de seguridad RM-3
Este producto puede conectarse eléctricamente a dispositivos que contienen rayos láser o diodos emisores de luz Clase 1M.
• Producto láser Clase 1M conforme a la norma IEC60825-1:1993+A1+A2
•PRECAUCIÓN: El uso de los controles o ajustes o procedimientos aparte de lo especificado aquí puede ocasionar exposición peligrosa
a la radiación.
• Deben tomarse precauciones para evitar la exposición a la radiación óptica cuando se saque la unidad de su alojamiento, o cuando se desconecte la
fibra de la unidad.
• Puede haber radiación láser en una conexión de fibra a esta unidad aun cuando se haya eliminado la corriente de la unidad.
• Esta unidad está destinada a instalarse en ubicaciones donde sólo el personal de servicio competente tenga acceso a las conexiones de fibra.
• Las ubicaciones de todas las conexiones ópticas se enumeran en la sección Ubicaciones de las conexiones y funciones de este manual.
• Las salidas ópticas y longitudes de onda aparecen en la sección Especificaciones de este manual.
Debe observarse la información de seguridad contenida en esta sección, y en otras páginas de este manual siemptre que se opere, dé
servicio o repare esta unidad. Si no se cumple con alguna precaución, advertencia o instrucción indicada en este manual se infringen los
estándares de diseño, fabricación y el uso destinado a la unidad. Optelecom-NKF no asume ninguna responsabilidad si el cliente no
cumple con alguno de estos reequisitos de seguridad.
RADIACIÓN LÁSER
NO VER DIRECTAMENTE CON INSTRUMENTOS ÓPTICOS (DE AUMENTO)
PRODUCTO LÁSER CLASE 1M
PRECAUCIÓN:
LOS CONECTORES ÓPTICOS DESCONECTADOS PUEDEN EMITIR ENERGÍA ÓPTICA
NO VER EL HAZ CON INSTRUMENTOS ÓPTICOS (DE AUMENTO)
Nivel de Riesgo 1M El borde debe ser negro y
el fondo debe ser amarillo.

iv
Die optischen Vorrichtungen in diesem Gerät haben Gefahrenstufe 1M. Wie vorgeschrieben durch IEC60825-1 ist der Installateur dafür verantwortlich,
sicherzustellen, dass die unten abgebildeten Schilder an den Orten mit eingeschränktem Zugang, an denen dieses Gerät aufgestellt ist, vorhanden sind.
Diese Baugruppe enthält Teile, die durch elektrostatische Entladungen (ESD) beschädigt werden können. Vorsichtsmaßnahmen
zum Schutz vor elektrostatischer Entladung treffen, wenn Teile oder Baugruppen berührt, ausgebaut oder eingefügt werden.
Das Gestell, in dem diese Einheit eingebaut ist, muss in einem entsprechend klassifizierten NEMA-Schutzgehäuse
untergebracht sein.
Wenn diese Einheit bei besonders hohen Temperaturen betrieben wird, können interne und externe Metallflächen extrem heiß
werden. Es muss darauf geachtet werden, dass diese Einheit in einem Bereich mit eingeschränktem Zugang aufgestellt wird,
damit nur geschultes Wartungspersonal Zugang zur Einheit hat.
Sicherheitsanleitungen RM-3
Dieses Produkt kann elektrisch an Geräte angeschlossen sein, die Laser oder LEDs der Klasse 1M enthalten.
• Laserprodukt der Klasse 1M gemäß IEC60825-1:1993+A1+A2
•VORSICHT: Wenn die Bedienungselemente anders als hier beschrieben bzw. andere Einstellungen verwendet werden, kann es zu
schädlicher Strahlenaussetzung kommen.
• Es müssen Vorsichtsmaßnahmen getroffen werden, um Aussetzung an optischer Strahlung zu vermeiden, wenn die Einheit aus dem Gehäuse
genommen oder die Faseroptik von der Einheit getrennt wird.
• In einer Faseroptik-Verbindung dieser Einheit kann auch dann Laserstrahlung vorhanden sein, wenn die Stromversorgung zur Einheit abgeschaltet wurde.
• Diese Einheit ist zum Einbau an Orten vorgesehen, an denen nur geschultes Personal Zugang zu den Faseroptik-Verbindungen hat.
• Die Lage aller optischen Verbindungen ist im Abschnitt über die Lage von Anschlüssen und Funktionsweise dieses Handbuchs zu finden.
• Optische Ausgänge und Wellenlängen sind im Abschnitt mit den technischen Daten dieses Handbuchs zu finden.
Die in diesem abschnitt und auf anderen seiten dieses handbuchs enthaltenen sicherheitsinformationen müssen befolgt werden, wenn diese einheit betrieben,
gewartet oder repariert wird. Falls vorsichtsmassnahmen, warnungen oder anweisungen in diesem handbuch nicht befolgt werden, verstösst dies gegen die
konstruktions, und herstellungsstandards und erfolgt im gegensatz zum vorgesehenen verwendungszweck dieser einheit. Optelecom-NKF übernimmt keine
haftung für das verabsäumnis des kunden, diese sicherheitsanforderungen einzuhalten.
LASER-STRAHLUNG
NICHT DIREKT MIT OPTISCHEN INSTRUMENTEN (LUPEN) ANSEHEN
LASER-PRODUKT DER KLASSE 1M
VORSICHT:
ABGEKLEMMTE OPTISCHE STECKVERBINDER KÖNNEN OPTISCHE ENERGIE FREI SETZEN
NICHT MIT OPTISCHEN INSTRUMENTEN (LUPEN) IN DEN STRAHL BLICKEN.
Gefahrenstufe 1M Schwarzer Rand und
gelber Hintergrund.

v
Les appareils optiques utilisés dans cet équipement correspondent à un niveau de danger 1M. Comme exigé par la norme IEC60825-1, il incombe à
l’installateur de s’assurer que l’étiquette ci-dessous est présente aux endroits d’accès limité où cet équipement est installé.
Cet ensemble contient des pièces sensibles aux décharges électrostatiques (ESD). Prendre les précautions relatives aux ESD avant
de toucher, retirer ou insérer des pièces ou des ensembles.
Le châssis dans lequel est installé cet appareil doit être placé dans une enceinte NEMA conforme aux spécifications nominales.
Lorsque cet appareil fonctionne à une température ambiante extrêmement élevée, il est possible que les surfaces métalliques
internes et externes deviennent extrêmement chaudes. S’assurer que cet appareil est installé dans une zone dont l’accès est
limité à un personnel de maintenance correctement formé.
Consignes de sécurité RM-3
Ce produit pourra être branché par un câble électrique à des appareils qui contiennent des lasers de classe 1M ou des diodes
électroluminescentes.
• Produit laser de classe 1M conformément à IEC60825-1:1993+A1+A2
•ATTENTION: L’utilisation de commandes ou réglages, ou de procédures différentes de celles indiquées ici risque de
provoquer une exposition dangereuse au rayonnement.
• Prendre des précautions pour empêcher une exposition au rayonnement optique lorsque l’appareil est retiré de son
boîtier ou lorsque le câble optique fibre est débranché de l’appareil.
• Un rayonnement laser pourra être présent dans un câble optique branché sur cet appareil, même une fois l’alimentation coupée.
• Cet appareil est prévu pour une installation à des endroits où seul un personnel de maintenance formé a accès aux câbles optiques.
• Les points de branchement de tous les câbles optiques sont indiqués à la section Points de branchement et fonction de ce manuel.
Les consignes de securite contenues dans cette section et dans le reste de ce manuel doivent etre respectees a chaque fois que cet appareil
est utilise ou fait l’objet d’une maintenance ou d’une reparation. Le non-respect d’une precaution, d’un avertissement ou d’une instruction
figurant dans ce manuel est une violation des normes de conception, fabrication et indication d’usage de l’appareil. Optelecom-NKF n’est
pas responsable du non-respect de ces consignes de securite par le client.
RAYONNEMENT LASER
NE PAS REGARDER DIRECTEMENT AVEC DES INSTRUMENTS OPTIQUES (LOUPES)
PRODUIT LASER DE CLASSE 1M
ATTENTION:
LES CONNECTEURS OPTIQUES DEBRANCHES PEUVENT EMETTRE UNE ENERGIE OPTIQUE.
NE PAS REGARDER LE FAISCEAU AVEC DES INSTRUMENTS OPTIQUES (LOUPES)
Niveau de danger 1M La bordure doit être noire et
le fond jaune.

Functional Description
A pair of 9971-C interface cards provide transmission for one 10 Base T Ethernet link and two independent 115
Kbps data channels via the duplex high-speed ports available on selected video or data over fiber transmission
cards. Currently, the 9971-C will operate with the 9252DT/DR, the 9421DT/DR, and the 9672 cards.
The cards operate on 6VDC as supplied by the chassis into which it is installed.
1

9971-C Indicator and Connector Locations
2
FIGURE 1
1. LINK INDICATOR
This indicator illuminates green when the RJ45 Ethernet port is connected to an active Ethernet connection.
2. FDUP INDICATOR
This indicator illuminates green when the RJ45 Ethernet port is operating in the full duplex mode.
3. HDUP INDICATOR
This indicator illuminates yellow when the RJ45 Ethernet port is operating in the half duplex mode.
4. ERR INDICATOR
This indicator illuminates red when the local RJ45 Ethernet port is operating full duplex and 9971-C at the
other end of the optical link is operating in half duplex or vice versa.
5. Rx INDICATOR
This green LED blinks when the RJ45 Ethernet port is receiving data.
6. Tx INDICATOR
This green LED blinks when the RJ45 Ethernet port is transmitting data.
7. 10 BASE T ETHERNET CONNECTOR
This RJ45 connector is the MIDX compatible Ethernet connector. It operates like a hub port and will
connect with a standard cable to a PC or other device. When connecting to a hub, use either the a
standard cable to uplink port on the hub or a crossover cable to a standard hub port.

8. LOOP INDICATOR
This three-color indicator provides status on the high-speed port connection to the opposite end of the link
• If red (No Sync, No Loop), there is a problem with the signal being received from the opposite end of
the link.
• If yellow (Sync, No Loop), the local receiver is receiving a good signal from the far end, but the far
end is not receiving the signal from the local end.
• If green (Sync, Loop), the local receiver has a good signal and the remote receiver is reporting a good
signal.
9. HIGH-SPEED PORT CONNECTOR
This RJ45 connector connects to the high-speed port on the fiber communication card via the provided
standard Cat5 Ethernet cable.
10. CHANNEL 1 DATA I/O CONNECTOR
This removable screw type connector serves as the I/O cable for data channel 1.
11. CHANNEL 2 DATA I/O CONNECTOR
This removable screw- type connector serves as the I/O cable for data channel 2.
12. S1 DIPSWITCH
This dipswitch sets half/full duplex mode for the Ethernet link.
3

Set Up and Operation of the 9971-C
Set up and operation of the 9971-C cards consists of setting the data port switches, installing the unit into a
Series 9000 chassis, connecting the provided Cat5 jumper cable from the high-speed port on the optical
communications card to the 9971-C. Any standard (not crossover) RJ45 Cat5 cable will also work correctly.
The card should be removed to set dipswitch S1, as the switch is only read during the power up cycle.
Setting S1 Dipswitch
4
TABLE 1
Switch S1 NOTE: Both ends of a 9971 link must be
operating in the same mode.The error LED will
illuminate if they are not operating in the same
mode.
Position 1 Position 2 Function
On On Half Duplex: Select this mode if one or both 9971s
are to be connected to half duplex device such as
a hub.
On Off Full Duplex: Select this mode if both 9971s are
connected to devices that are set/forced to
10 mbs full duplex.
Off Off Auto-Negotiate: Select this mode when connecting
to 10/100 full duplex device, such as a switch.
NOTE: This mode is, strictly speaking, not valid
for a 10 mbs only device such as a 9971. The
Auto-Negotiate process may fail when connecting
to a switch that already has heavy traffic running.
The failure can be observed by the fact that the full
duplex LED is blinking. The workaround is to
temporarily remove the source of the traffic until
the 9971 Auto-Negotiate completes.

5
Limitations for Half Duplex
When an Ethernet link operates in the half duplex mode, there are limitations imposed on the end-to-end
length of the system. Operating on fiber does not change these limitations and the user should be aware
that, in general, the collision domain limits the total network diameter to 4000 meters or less, including fiber
runs. If portions of the system are operating at 100 Mbps, the distances may be less.
Setting the Data Port Mode Switches
The 9971-C supports two Data Option Module Type B Plug-ins. The switches on each one are identical and are
set according to the charts below.

Option Module Type B — Duplex Data
SET UP
Compared to the first and interim versions, the latest version has an additional bias switch to set for more robust RS485
operation of the data module. The bias resistors keep the differential signal pair biased so that when it is in a High-Z state the
line receivers interpret the line as being inactive (no data transmitted). Refer to Table B-2 for connector and switch locations.
• Left hand connector row(s) (nine pins each).
• Switch S1: This eight position dipswitch is used in conjunction with dipswitches S2 and S3 to select the
data interface. Refer to Table B-2 for setting this switch.
• Switch S2: This six position dipswitch is used in conjunction with dipswitches S1 and S3 to select the data
interface. Refer to Table B-2 for setting this switch.
• Switch S3: This four position dipswitch is used in conjunction with dipswitch S1 and S2 to select the data
interface. Refer to Table B2 for setting this switch.
• Right hand connector rows (seven pins each).
NOTE:Both inputs and outputs on both ends of the link are set independently and can be configured as different
data types. This allows different interface settings on each input and output on both ends of a data link. For
example, one end of the link could be configured for RS232 and the other for RS485 4-wire. The Option Module
converts the data in and out to the selected data types. This eliminates the need for data converters.
NOTE: Use this table only for the latest version.
6
TABLE B-2 — INTERFACE SELECTION TABLE
Data Interface Settings (Latest Version)
Input/Output Type Switch S1 Switch S2 Switch S3
123456781234561234
RS232 Input OFF ON OFF OFF OFF
RS232 Output OFF OFF ON OFF OFF OFF
RS422 Input T T ON ON T ON OFF ON ON* ON*
RS422 Output OFF OFF OFF OFF ON OFF OFF
RS485 4-Wire Input T T ON ON T ON OFF ON B B
RS485 4-Wire Output OFF ON OFF OFF ON B B
RS485 2-Wire (Duplex) T T ON ON T ON OFF ON ON ON OFF OFF B B
Manchester Input T T OFF OFF ON ON OFF ON OFF OFF
Manchester Output OFF OFF ON OFF ON OFF OFF
NOTES:
* Setting S3, positions 1 and 2, to the “On” position for RS422 insures that the input line receiver interprets
the input as “inactive” under all conditions if there is no active RS422 signal driving the input. If this is not
important, these switches can be left in the “Off” position.
• “T” indicates Termination Resistor. When set to the “On” position, the Termination Resistors are enabled;
“Off” disables the Termination Resistors. Refer to the Termination Rules Section.

• “B” indicates Bias Resistors. The bias resistors may be necessary on RRS485 systems to eliminate data
errors. Information on setting these resistors can be found in the Termination Rules section (page 17).
• Empty locations do not apply to the particular Input or Output type listed on the left side.
• When using bidirectional or duplex data, you must set both the input and output switches to the correct data type.
Option Module Type B — Duplex Data
EXTERNAL CONNECTIONS
Connections are made to the module via the 5-pin removable screw terminal connector. Refer to the
following tables and figures for the connection configurations. Note that on all signal connection drawings,
the arrows indicate signal flow direction.
RS232
Option Module type B supports 3-wire RS232 communications. The signal input to pin 1 of the terminal block
is transmitted to the other end of the link and is output on pin 3. Care must be taken to insure that the
external equipment is connected input to output and output to input.
7
TABLE B-3 — OPTION MODULE B RS232 SIGNALS AND CONNECTIONS
Pin # Function RS232 (DTE) Signal Name
1 Input RD
2 No Connection
3 Output TD
4 No Connection
5 Signal Common Common
TD
RS232 Connections
COM
RD
1
2
3
4
5
Optical
Link
Host
Card
Host
Card
1
2
3
4
5
Type B Option Module Type B Option Module
Connected
Equipment
TD
COM
RD
Connected
Equipment
Optelecom-NKF Equipment
FIGURE B-4 — RS232 CONNECTIONS

RS422
Option Module B supports both 2-wire (simplex) and 4-wire (duplex) RS422 communications. RS422 is a
differential communications scheme and uses the polarity difference between the + and – leads to transmit
the data bits. The signals input on pins 1 and 2 at one end of the link are transmitted to the other end of the
link and are output on pins 3 and 4.
Different manufacturers mark their RS422 devices in different ways and there is no consistent common
terminal marking scheme. In RS422, when there is no data activity, the system is said to be in a mark state.
During data transmission, the system toggles between mark and space states. During idle (mark state), when
no data is being transmitted, the output + terminal will be positive with reference to the output – terminal.
Care must be taken to ensure that external equipment has its output terminals connected to the external
equipment input terminals. Connect + to + (plus) and – to – (minus).
RS422 is a “one-to-many” type system, permitting up to 10 receivers to be electrically connected to one
transmitter. Refer to the “Termination Rules for RS422, RS485, and Manchester” on page 15 for more details
on terminations to ensure you have terminated multiple connections correctly. Fiber connections isolates
each end of a system, effectively creating more than one electrical buss. A system controller for Pan, Tilt, and
Zoom (PTZ) could connect to up to 10 B-type Option Module inputs, with only the last input having the
termination enabled. At the other end of each link, each RS422 output could drive 10 more inputs. Since this
end of the link is optically isolated from the transmit end, it must be treated as a separate system and should
have the last input in the daisy chain terminated.
Although RS422 and RS485 are differential input communications standards and are more immune to noise
caused by poor grounding and electrical noise, the shielding and grounding of the signal wires is still important.
Signal grounds and shields should be connected at both ends on most signal runs. When the ground potential
of one end of the electrical connection is at a different potential than the other, the voltage differential can
exceed the maximum common mode immunity of the input circuits and cause improper operation of the
equipment. If this voltage should become exceedingly large due to lightning or static buildups, damage to the
signal inputs is possible. Connecting the ground (and shield) connections on both ends reduces this potential.
Data connections in outdoor locations (traffic and external security systems, for example) are especially
vulnerable to these kinds of problems and should have grounds connected at both ends of the wiring. In
addition, power, data, and video signals should have noise and surge protection modules installed in the lines
ahead of the communications equipment.
Refer to the section on “Termination Rules’ for more details on RS422 termination.
8
TABLE B-4 — OPTION MODULE B RS422 SIGNALS AND CONNECTIONS
Pin Number Function
1 Input +
2 Input –
3 Output +
4 Output –
5 Signal Common

RS485
Option Module B supports both 2-wire (duplex) and 4-wire (duplex) RS485 communications. RS485 is a
differential communications scheme and uses the polarity difference between the + and – leads to transmit
the data bits. It is similar to RS422, but has the capability of paralleling transmitters because the transmitters
are tristated (shut off) when not actually transmitting data. Because of this, a duplex or bidirectional link can
be operated on either two or four wires. In 4-wire operation, the signals input on pins 1 and 2 at one end of
the link are transmitted to the other end of the link and are output on pins 3 and 4, respectively. For 2-wire
operation, the signals input on pins 1 and 2 at one end of the link are transmitted to the other end of the link
and are output on pins 1 and 2.
Different manufacturers mark their RS485 devices in different ways and there is no consistent common
terminal marking scheme. During data transmission, the system toggles between mark and space states.
Care must be taken to ensure that external equipment has its output terminals connected to the Option
Module input terminals and the Option Module output terminas are connected to the external equipment
input terminals. Generally speaking, connect + to + (plus) and – to – (minus). In rare cases, you may have to
connect the Option Module + (plus) to the external equipment – (minus) and the Option Module – (minus) to
the external equipment + (plus).
9
RS422 2-Wire Connections
(Simplex)
1
2
3
4
5
Optical
Link
Host
Card
Host
Card
1
2
3
4
5
Type B Option Modules Type B Option Modules
TX+
TX–
GND
COM
Connected
Equipment
RX+
RX–
GND
COM
Connected
Equipment
Optelecom-NKF Equipment
FIGURE B-6 — RS422 2-WIRE SIMPLEX CONNECTIONS
RS422 4-Wire Connections (Duplex)
1
2
3
4
5
Optical
Link
Host
Card
Host
Card
1
2
3
4
5
Type B Option Module Type B Option Module
TX+
RX+
TX–
RX–
GND
COM
TX+
RX+
TX–
RX–
GND
COM
Connected
Equipment
Connected
Equipment
Optelecom-NKF Equipment
FIGURE B-5 — RS422 4-WIRE DUPLEX CONNECTIONS

10
RS485 2-Wire Connections (Duplex)
1
2
3
4
5
Optical
Link
Host
Card
Host
Card
1
2
3
4
5
Type B Option Modules Type B Option Modules
+
–
GND
COM
Connected
Equipment
+
–
GND
COM
Connected
Equipment
Optelecom-NKF Equipment
FIGURE B-7 — RS485 4-WIRE CONNECTIONS (DUPLEX)
RS485 4-Wire Connections (Duplex)
1
2
3
4
5
Optical
Link
Host
Card
Host
Card
1
2
3
4
5
Type B Option Module Type B Option Module
TX+
RX+
TX–
RX–
GND
COM
Connected
Equipment
TX+
RX+
TX–
RX–
GND
COM
Connected
Equipment
Optelecom-NKF Equipment
FIGURE B-8 — RS485 2-WIRE CONNECTIONS (DUPLEX)
TABLE B-5 — OPTION MODULE B RS485 SIGNALS AND CONNECTIONS
Pin Number Function
4-Wire 2-Wire
1 Input + Input/Output +
2 Input – Input/Output –
3 Output + Internally Connected to Pin 1
4 Output – Internally Connected to Pin 2
5 Signal Common — Chassis Ground

11
TABLE B-6 — OPTION MODULE B MANCHESTER SIGNALS AND CONNECTIONS
Pin Number Function
1 Input +
2 Input –
3 Output +
4 Output –
5 Signal Common
RS485 is a “many-to-many” type system, permitting up to 32 devices or receivers to be electrically connected
to one transmitter. Refer to the “Termination Rules for RS422, RS485, and Manchester” later in this section for
more details on terminations to ensure you have terminated multiple connections correctly. The fiber
connection isolates parts of a system, effectively creating more than one electrical buss. A system controller
for Pan, Tilt, and Zoom (PTZ) could connect to up to 32 B-type Option Module inputs with terminations
required on both physical ends of the buss having the termination enabled. At the other end of each optical
link, each RS485 I/O could interface with 31 other I/Os. Since this end of the link is optically isolated from the
transmit end, it must be treated as a separate system and has each end of its bus terminated.
Although RS422 and RS485 are differential input communications standards and are more immune to noise
caused by poor grounding and electrical noise, the shielding and grounding of the signal wires is still important.
Signal grounds and shields should be connected at both ends on most signal runs. When the ground potential
of one end of the electrical connection is at a different potential than the other, the voltage differential can
exceed the maximum common mode immunity of the input circuits and cause improper operation of the
equipment. If this voltage should become exceedingly large due to lightning or static buildups, damage to the
signal inputs is possible. Connecting the ground (and shield) connections on both ends reduces this potential.
Data connections in outdoor locations (traffic and external security systems, for example) are especially
vulnerable to these kinds of problems and should have grounds connected at both ends of the wiring. In
addition, power, data, and video signals should have noise and surge protection modules installed in the lines
ahead of the communications equipment.
Refer to the section on “Termination Rules” for more details on RS485 termination.
MANCHESTER
The B Option Module supports the different types of Manchester encoded data including Pelco D, Philips
(Burle), American Dynamics, Bi-Phase, and other similarly encoded data signals. It is normally a simplex
transmission (single direction) and operates on two wires. It operates differently than RS232, RS422, or RS485,
but does require that the end of the buss be terminated as in RS422. Although the diagram in Figure B-8 does
not indicate so, the link does operate in both directions with the inputs always on pins 1 and 2 and the outputs
at the opposite end of the link on pins 3 and 4. Typically Manchester is not used as a duplex or bidirectional link.
Refer to the “Termination Rules for RS422, RS485, and Manchester” later in this section of the manual to
ensure you have terminated multiple connections correctly.

TERMINATION RULES FOR RS422, RS485, AND MANCHESTER
On RS422, RS485, and Manchester connections, it is possible that multiple devices may be connected in parallel.
In RS422 systems, this is usually a transmitter and many receivers connected together. In RS485, it is many
transceivers. In these configurations, a parallel bus is created and it must be terminated correctly for proper
operation. Use the following rules to determine if the termination resistors should be enabled or disabled.
• 4-Wire RS422 and RS485
Terminate only the last transceiver I/O, leaving all other I/Os unterminated.
Terminations should only be made at the physical end of the electrical wiring.
RS422 and RS485 4-wire interfaces should never be connected in a “star” type configuration, but in
daisy chain. “Star” configurations cannot be terminated correctly.
• 2-Wire Duplex RS485
Terminate both ends of the bus. Since any device can be a transmitter or receiver, both ends of the
bus require the terminations be enabled; leaving all other I/Os unterminated.
Terminations should only be made at the physical end of the electrical wiring.
RS485 2-wire should never be connected in a “Star” type configuration, but in daisy chain. “Star”
configurations cannot be terminated correctly.
• Manchester
Terminate only the last input if there are fewer than five inputs. If there are more than five inputs,
leave all inputs unterminated.
Refer to Figures B-10 and B-11 for the termination examples.
SETTING THE BIASING RESISTORS (Switch 3, positions 1, 2, 3, and 4)
The biasing resistors may need to be enabled to insure that RS485 the communications bus is never left in a
“floating” condition when the bus is not being driven. An RS485 bus left in the “floating” condition may not
provide reliable communications. Many devices already have these resistors permanently installed and, in that
case, the biasing resistors may set to disabled (off). In cases where the communications system does not
appear to operate reliably, it may be necessary to enable the biasing resistors. It is unlikely that this condition
will occur in RS422 systems.
Dipswitch positions 1 and 2 enable/disable 390 ohm bias resistors for the terminals 1 and 2, which serve as
the input terminals in a 4-wire system and as the I/O terminals in a 2-wire system. Dipswitch positions 3 and
4 enable/disable 390 ohm resistors on terminals 3 and 4, which serve as the output terminals in an RS485 4-
12
Manchester (Bi-Phase)
1
2
3
4
5
Optical
Link
Host
Card
Host
Card
1
2
3
4
5
Type B Option Module Type B Option Module
TX+
TX–
GND
COM
Connected
Equipment
RX+
RX–
GND
COM
Connected
Equipment
Optelecom-NKF Equipment
FIGURE B-9 — MANCHESTER CONNECTIONS