fdm-fsk - gdi communications aug 06 fdm-fsk preliminary user guide dwg: a01230 fdm series of fiber...

16 Aug 06 FDM-FSK Preliminary User Guide Dwg: A01230

(TI) 16 August 2006

GDI COMMUNICATIONS LLC PO Box 1330 280 I-80 Exit 1

Verdi, NV 89439

Phone: (775) 345-8000 Fax: (775) 345-8010

Email: [email protected]

FDM-FSK Fiber Optic Modem

With Built in Model 4xx Series

FSK Modem

USER GUIDE

FDM Series All Fiber Topologies - Compliant

16 Aug 06 FDM-FSK Preliminary User Guide Dwg: A01230

FDM Series of Fiber Optic Modems

• Multiple Fiber Topologies in One Modem Single Ring, Dual Redundant Rings, Daisy Chain and Point to Point.

• Combination Fiber Optic and FSK Modems Built in FSK Modems for 2/4 wire Copper and Fiber Applications.

• Intuitive Fiber Status Display

Pictorially indicates the switching status of the modem.

• Fiber Identification

Display shows a 1 or 2 to indicate which port the fiber belongs.

• Generates DTE Handshaking

Necessary for Remote Fiber to 2/4Wire FSK to TMC applications.

• Auxiliary Data Port

For 2/4Wire FSK or SS Radio Branch Circuits.

• Built-in Uninterruptible Power Supply

Provides Optical Continuity at a Failed Intersection.

AUXPORT

RJ45

1 RI

3 DTR2 CD

4 SG

RXD 5 TXD 6CTS 7RTS 8

MODEL FDM170GDI Communications LLC

Verdi NV 89439775-345-8000

IN

OUT

R1T2

T1

R2

MODEM

FIBER STATUS

PWR

FAIL

1 8

ENABLE

DISABLE BAT

TER

Y

AU

X C

ON

N

FDM2SA

GDI Communications

TXD

RXD

Data PortsKOD RTS

Anti-Strm

Reset

T1

R2

R1

T2

LOS

LOS

MainDC Power Center

Battery

Alarm Charging

RING 2

RING 1

R1

R2T2

T1

LOS

LOS

PWR

RING STATUS

MAIN DATA ALARM

RESET

ANTI-STREAM

AUX DATA

SERIAL PORT

TXD RXD

TXD RXD

TXD RXD

FDM

2070-6D

GDINEVADA

Fail

R2

T1

T2

R1

FDM2SA

FDM170

FDM2070

FDM-FiberHub

R1 T2

GDI Communications

TXD

RXD

Link Activity

Data Port Anti- Streaming

TXD

RXD

Alarm Reset

AB CD

D

T1

R2

R1

T2

T1 R2

A B

CLOS

LOS

LOS

LOS

MainDC Power Center

Battery

Alarm Charging

FDM-FiberHub

FDM-FSK

GDI Communications

TXD

RXD

Data PortsKOD RTS

Anti-Strm

Reset

T1

R2

R1

T2

LOS

LOS

MainDC Power Center

Battery

Alarm Charging

CD

RTS

2/4 Wire FSKKOD

CTS

TXD RXD

A B

FDM-FSK

Stand Alone Models Plug-in Models for Controllers and Racks

16 August 06 FDM-FSK Preliminary User Guide 1 Dwg: A01230

FDM -FSK ----- Table of Contents------ Page 1/3

FDM Series Overview 4

The FDM Series 4

FDM170 5 FDM2070 5 FDM-FiberHub 6 FDM2SA 6

Introduction to the FDM-FSK Modem 7

FDM-FSK

Basic Signal Flow Diagram 7 FSK Modem Section 7 Modem Ergonomics 8

Front Panel 8

Fiber Optic Modem Display s 9 Data Port Activity Display 9 TXD LED 9 RXD LED 9 Data Port Anti- Streaming 9 Reset Switch 9 Intuitive Fiber Status Displays 9 Fiber Identification 9 Fiber Status Displays for Redundant Rings and Daisy Chains 10 Fiber Status Displays for Single Rings 10

2/4 Wire LED Displays 11

CD Carrier Detect 11 KOD Key On Data 11 RTS Request To Send 11 CTS Clear To Send 11 TXD Transmit Data 11 RXD Receive Data 11

DC Power Center Display 11

DC Power Center LED Indicators 12 Main 12 Charging 12 Battery 12 Alarm 12


Rear Panel 12 Power Connections 12 Dual Data Ports 13 Optical Ports 13

Bottom Panel 13 Signal Flow Diagrams 14

Sequence of Events 14 Data Port Flow Diagrams 15

Setting up the Modem 16

Mounting Options 16 Configuring the FDM Modem Section 16

FDM DIP Switches 17

Master/Salve 17 Topology Selections 17 2 Rings (Self Healing Dual Counter Rotating Rings). 17 1 Ring 17 Daisy Chain 17

Data Protocol RS232/422 18 Baud Rates 18 Parity 18 RTS/CTS Handshaking 18 CTS Delay 18 Anti-Streaming 19

Optical Dynamic Range 19

Fiber Identification Techniques 20

Fiber Applications 21 Self Healing Dual Counter Rotating Ring Operation 21 Single Ring Operation 23 Point to Point 25 Point to Point with Redundant Fiber Path 26 Daisy Chain Operation 28 Dual Daisy Chain (Center Master) 30


Configuring the FSK Modem Section 31

Primer on Frequency Shift Keying Modems 31 Communications Sequence of Events 32

The Pole 32 The Response 33

Front, Rear and Bottom Panels 34

2/4 Wire FSK Display CD 34 RTS 34 CTS 34 TXD 34 RXD 34 KOD 34

Rear Panel 34 Copper FSK 34

Bottom Panel DIP Switches 35

Full Duplex or Half Duplex 35 RTS to CTS Time 35 Carrier Turn Off Time 35 Local Echo 35 Receiver Squelch Time 35 Carrier Detect Time 35 Load Compensation 35

FSK Applications 36 Half Duplex Operation (2 Wire “One Pair”) 36 Full Duplex Operation (4 Wire “2 Pairs”) 37 A Word on Dynamic Range 38

Combined FDM and FSK Applications 39 Fiber to Copper to Fiber --- Copper Bridge Application 40 Copper to Fiber to Copper --- Fiber Bridge Application 40 Fiber with Copper Branch --- Copper Tap Application 41

Factory Default Settings and Pin-Out Diagrams 42 KOD Jumper 43 Care and Handling Procedures for Optical Connectors 44 Disclaimer 47


FDM SERIES OVERVIEW

The FDM Series of Hardened Modems are designed for polling applications utilizing

RS232/422 Asynchronous transmission over Multimode and Singlemode Fiber Optics. All modems in the series are communications compatible with each other, thus allowing greater flexibility of use. The FDM Series comprise of six Digital Modems:

1. The FDM2SA is a Stand Alone version. 2. The FDM170 is a Plug-in version for the 170 Controller 3. The FDM2070 is a Plug-in version for the 2070 Controller 4. The FDM FiberHub performs as a 1 x 3 star optical hub that ties in

optical branch circuits into the mainstream communications path. 5. The FDM-FSK is a combination of a FDM2SA and a FSK modem. 6. The FDM-SSR is a combination of a FDM2SA and a Spread Spectrum

Radio. The modems can operate in many different topologies, even on a simple fiber ring when there is only one fiber available, later as more fibers become available, simply flip a switch to change to the new topology. This unique capability of operating in multiple topologies offers the advantage of One Modem for all Topologies. Switch Selectable Topologies are as follows:

• Single Fiber Ring • Dual Fiber Redundant Ring (Self Healing) • Point to Point • Daisy Chain Format.

The modems have a high dynamic range yet they are immune to optical over loads, therefore no optical attenuators are required for short runs or even bench top “back to back” testing! Any modem can be designated as a Master or Slave, also for Auto Restoration any modem can be designated as an Auxiliary Master.


FDM SERIES OVERVIEW continued

A unique and intuitive Dual Seven Segment display graphically indicates the status of the fiber system, making diagnostics visually simple. All FDM series modems have the unique capability of Fiber Identification; the display will flash a 1 or 2 indicating which circuit the fiber belongs to. Other advantages include multiple use Dual Data Ports enabling branch circuit capabilities such as an On Street Master to Local Controller (same location), or 4wire or Spread Spectrum Radio communications. All modems have the unique capability of having their Auxiliary Port switched from DCE to DTE mode. This feature allows the Main port to drive the Aux-Port as well as the fiber, primarily used for Street Master communications with the local controller or driving some other modem. Only FDM optical modems have the unique ability to generate a Carrier Detect both before and after data flow, this is essential when connecting to 2 Wire FSK communications. This Dynamic CD acts like a “DTE’s RTS” and is used to initiate handshaking to a DCE’s RTS input. The FDM Series represents a new generation of digital fiber optic modems utilizing a Replaceable Operating System (ROS). As requirements change, or new features become available, a new program can be loaded so as to provide a migration path to upgrade the existing system.

FDM170

This is a Plug-In version for the 170 Series of Controllers and the R400/R800 Rack Series. The Main Data port is connected via the card edge connector to the 170 backplane while the Aux Data Port RJ45 is front accessible for combining external data links in the polling stream. For rack-mounted communications at the Traffic Maintenance Center, R400/R800 Series Racks can be populated with the FDM170 to complete the communications system.

FDM2070

This is a Plug-In version for the 2070 Series of Controllers. The Main and Auxiliary Data ports provide the same functionality as in the FDM170, plus one of the 2070’s spare Serial Ports SP2 or SP4 (slot dependant) is also brought out to the front panel. For rack-mounted communications at the Traffic Maintenance Center, R400/R800 Series Racks would be populated with the FDM170 to complete the communications system.


FDM FiberHub The FiberHub is designed to act like a hub or star that ties four optical branch circuits together in a 1 x 3 A typically deployment would be anywhere in a fiber arterial daisy-chain or ring at an intersection where it ties in the “North/South” cross street optical branch circuits into the “West/East” main arterial fiber run. As with all FDM modems , data ports are provided for the local controller and auxiliary communications.

FDM2SA

This is the “Stand Alone” version and has two Data Ports, one designated as the Main Port, the other being an Auxiliary Port. The Main Data Port is used for connection to a controller. The Auxiliary Data Port can be used for many associated functions such as connecting to a Backup Server or for Over the Air Restoration, or combining external data links into the polling stream. A unique built-in Key on Data capability allows the fiber modem to act as DTE and provide all necessary handshaking. This unique feature allows a Remote Fiber System (Tail Circuit) to be integrated into a 4wire FSK circuit and on to city hall.

FDM-FSK

This user guide describes the FDM-FSK and its operation.

N

W E

S


INTRODUCTION to the FDM-FSK

FDM-FSK

The FDM-FSK is a combination of the FDM2SA Fiber Optic Modem and GDI’s Model 4xx Series FSK Modem, basically it is two interconnected modems housed in the same enclosure. Two RS232 Data Ports are provided along with the 2/4 Wire FSK Port, all three ports communicate to and from the fiber to the originating “master source”, see diagram below.

Basic Signal Flow Diagram

FSK Modem Section The FSK Modem is based on the industry standard Model 4xx series of modems which are designed for asynchronous RS232 communications over un-terminated private wire utilizing Frequency Shift Keying techniques (tones). The modems data port is tied into the fiber optic data stream to provide bi-directional communications between Fiber and FSK. The FSK Modem can communicate in 2 Wire Half Duplex or 4 Wire Full Duplex at baud rates up to 19.2Kbt/s depending on which FSK Modem is installed. The FSK modem is 100% compatible with all GDI modems. The FSK section allows a number of options:

• Connecting a remote copper 2/4 wire circuit into the fiber system and back to City Hall.

• Connecting a remote fiber system into the 2/4 wire system and back to

City Hall.

• Connecting Copper to Fiber to Copper. (Fiber Bridge) • Connecting Fiber to Copper to Fiber. (Copper Bridge)

FDM-FSK FDMSeries

FSK 2 or 4 WireMain Port

Aux-Port

Main Port

Aux-Port

FDMMain PortFiber Optics

Aux-Port

TMC or Street Master Remote ControllerLocation

Remote ControllerLocation

Series

FDM2SAFDM170FDM2070FDM-SSRFDM-FiberHub

Main Server

Back-up Server

Master

Fiber Trunk

MainPort

Aux-Port

T1

R2T2

R1

2/4WirePort

Fiber Trunk

RS232 RS232 2/4 Wire

FSKModem

FDM2SAFiber Optic

Modem

FDM-FSK Modem


Modem Ergonomics The Front Panel displays information on the status of the FDM-FSK. The Rear Panel is where all the connections are made to the modem and the switch-able options are located on the Bottom Panel to minimize ingress of foreign material in road side cabinet applications. On the Rear Panel, there are two dual bulkhead Fiber Ports which can be easily changed between ST, FC and SC style connectors; so can the internal mini patchcords located between the bulkheads and the optical transceivers. These inexpensive patchcords act like a “fusible link” and provide the transceivers with 100% protection from being damaged by external dirty patchcords. Replacing the patchcords can be easily done by the customer. Two Data Ports, Main and Auxiliary are provided, the Main Data Port DB9 typically connects to the local controller while the Auxiliary RJ45 connector can be used to bring in radio based communications into the main data stream. The FSK Port can operate in 2 or 4 wire mode (Half/ Full Duplex) and is 100% compatible with all GDI FSK Modems The FDM-FSK has three mounting options, left or right wall mounting via a pair of “Keyhole” slots on both sides, or as a Stand Alone shelf mounted unit while still maintaining a vertical front panel view for all three options. The FDM-FSK has an optional internal Uninterrupted Power Supply “UPS” that maintains full modem operation without any loss of communications.

Front Panel Displays The FDM-FSK front panel has three distinctive information displays:

• The upper display is for the Fiber Optic Modem. • The middle display is for 2/4 wire FSK Modem.

• The lower display is dedicated to the DC Power Center

FDM-FSK

GDI Communications

TXD

RXD

Data PortsKOD RTS

Anti-Strm

Reset

T1

R2

R1

T2

LOS

LOS

MainDC Power Center

Battery

Alarm Charging

CD

RTS

2/4 Wire FSKKOD

CTS

TXD RXD

BA


Fiber Optic Modem Displays

Data Ports Activity Display This section displays the activity of data through the modem.

TXD LED This indicates data activity from the fiber to the data port.

RXD LED This indicates data activity from the data port to the fiber.

KOD

This indicates Data from the fiber is asserting (Keying) the FSK Modem’s RTS and the Auxiliary Port’s DCD.

Data Port Anti-Streaming Alarm LED This indicates port data exceeded selected time out.

Reset Switch Switch for resetting Anti-Streaming Alarm.

Intuitive Fiber Status Displays

The seven segment displays show information as to the integrity of the fiber system, each of the red segment lines represent the incoming or outgoing fiber data path through the modem, while LOS indicates a loss of incoming optical signal.

Fiber Identification Identifying whether a fiber has Receiver 1 or Receiver 2 traffic is as simple as plugging in and out each fiber into any receiver, the modem will flash the message 1or 2 to denote which receiver that fiber belongs to.

See Installation Section -- Fiber Identification Techniques, page 22 for more details.

T1

R2

R1

T2A B

LOS

LOS

R2

Display indicates patchcord belongs in R2.

T1

R2

R1

T2A B

LOS

LOS

R1

Display indicates patchcord belongs in R1.

TXD

RXD

Data PortsKOD RTS

Anti-Strm

Reset

T1

R2

R1

T2

LOS

LOS

A B

TXD

RXD

Data PortsKOD RTS

Anti-Strm

Reset

T1

R2

R1

T2

LOS

LOS

A B


Fiber Status Displays for Redundant Rings and Daisy Chains

Fiber Status Display for Single Rings

Loss of signal on R1 Displays will Flash Displays will Flash

T1R1LOS

T1R1LOS

T1R1LOS

T1R1LOS

T1R1

LOS

T1R1LOS

T1R1LOS

T1R1

LOS

T1R1LOS

Master

Master

Master

Master

Slave 1

Slave 1 Slave 2

Slave 1 Slave 2

T1

R2

R1

T2

LOS

LOS

Red

unda

nt R

ing

Dis

play

sCommon Displays

Dai

sy C

hain

Dis

play

s

Loss of Signal Causes Local LOS and Fold Back toFlash (Ring Alarm Condition).

Normal Display.(Displays not Flashing)

T1

R2

R1

T2

LOS

LOS

T1

R2

R1

T2

T1

R2

R1

T2

T1

R2

R1

T2

Loss Of SignalLOS LED’s Flashing

LOS

LOSS of R1 causesR2/T2 Foldback

First Modem setto Daisy Chain

Last Modem setto Daisy Chain

T1

R2

R1

T2

T1

R2

R1

T2

LOSLOSS of R2 causes

R1/T2 Foldback

No LOS by default on firstmodem

No Fiber No Fiber

LOS

No LOS by default on lastmodem

Flashing Display indicates aTransport Layer fault on the

Fiber System.All Modems Flash


2/4 Wire FSK Display

This section displays the activity of data through the FSK Modem.

CD LED This indicates the modem has detected a carrier tone from a remote modem on the 2/4 Wire circuit.

KOD This indicates Data from the fiber is asserting (Keying) the FSK Modem’s RTS.

RTS LED

This indicates the Fiber Optic modem has asserted RTS to the FSK modem.

CTS LED This indicates the FSK modem has asserted CTS to the Fiber Optic Modem.

TXD LED

This indicates data is being transmitted from the Fiber Optic modem to the FSK Modem.

RXD LED This indicates data is being received from the FSK Modems 2/4 Wire circuits

DC Power Center Display The DC Power Center shows the power state of the FiberHub.

The DC Power Center provides information on the status of the optional internal Uninterrupted Power Supply (UPS), such as incoming Main power, battery Charging (full and trickle charge), Alarm (no external power) and Battery power only. If the modem is equipped with an optional internal UPS and power fails, the supported modem(s) will be fully operational until the batteries are depleted. Resumption of power will start the battery charging process while at the same time the modem will be fully operational. If the installation site supports a 24VDC UPS this may be connected to the DC power connector on the modem in lieu of an internal UPS.

MainDC Power Center

Battery

Alarm Charging

Normal Condition

Running on Main Power andcharging the batteries

MainDC Power Center

Battery

Alarm Charging

Incoming Power Failure

Running on Battery Power withan Alarm indication.

CD

RTS

2/4 Wire FSKKOD

CTS

TXD RXD


DC Power Center LED Indicators

Main Indicates the modem is running of external power and is paired with the Charging LED.

Charging

The LED has two indicating modes,

1. On Solid, this indicates the battery is being charged at the maximum rate.

2. Pulsing indicates the battery has reached a full charge state and is being maintained. Pulse duty cycle varies with the state of charge.

Battery

Indicates the modem is running on batteries only and is paired with the Alarm LED.

Alarm Indicates external power has failed.

Rear Panel

The rear panel is where the Fiber Optic, Data, FSK 2/4Wire and Power connections interface to the modem, note that the fiber connections logically match the front panel fiber displays. The FSK connection diagram illustrates how to correctly connect 2 or 4 wire copper applications.

Power Connections

The modem can be connected to an external 24VDC UPS via the DC Jack, also a battery disconnect switch is provided for shipping or storage purposes.

BatteryEnable

Disable

18-30VDC

MainDC Power Center

Battery

Alarm Charging

MainDC Power Center

Battery

Alarm Charging

MainDC Power Center

Battery

Alarm Charging

T2

R1

R2

T1

18-30VDCBattery

Enable

Disable

1 8

Main

Aux

Ports

1 8

4W FSK2W

In Out

A B


Dual Data Ports (FDM)

The fiber optic modem has Dual RS232 Data Ports (Main and Auxiliary). This is a single channel with dual ports, the main Data Port DB9 connector goes to the local controller while the Auxiliary RJ45 connector can be used to bring in auxiliary or radio based communications into the main data stream. The Aux Data Port can be switched to operate as RS422 interface.

Optical Ports

The craft friendly layout of the optical ports matches the Front Panel Fiber Display which makes for ease of installation. The designation A & B refer to Port Designations when connecting to the FDM-FiberHub. The optical ports are dual hybrid adapters that are easily interchangeable should a different style of connector be required such as ST, FC and SC. These hybrid adapters are coupled to the main optical transceivers through replaceable mini patchcords that isolate and protect the main optics from damage due to external dirty or damaged patchcords.

Bottom Panel This panel is where the FDM-FSK is set up for Fiber and FSK Operation. Data rates on both the FDM and FSK modems must be the same for obvious reasons.

Pin out connection diagrams are also included on this panel to assist the technician when making interconnect cables. The FSK Connections are shown on the rear panel. Switch settings are described on page 17 for the FDM and page 35 for the FSK.

1 8

Main

Aux

Ports

1 8

T2

R1

R2

T1

A B

SlaveOff1 RingRingRS485OffOffOffOffOffOffOff

Parity NoneOdd Even

RTS-CTS OffCTS-0ms 8msAnt-Strm Off

248

1832 64 Off

Aux.Port DCE DTE

MasterAux. Master

2 RingsDaisy Chain

RS232120024009600

19.2Kbts38.4Kbts57.6Kbts

115.2Kbts

Port Switch Assignment

Data Port Pinouts

RS-232 RJ45

Auxiliary

1 8

2 DCD4 GND5 RXD

6 TXD7 CTS8 RTS

NO CONNECTIONPINS 1-3

DCDRXDTXD

GND

CTS RTSNO CONNECTION

PINS 4-6-9

MainRS-232 Female

15

69

FullDuplex

12ms 6ms10ms 5ms

(Full) Off On (Half)6ms 3ms8ms 4ms

Hi 600 Ohms

Switch Actuator

HalfDuplex

RTS to CTS TimeCxr. Turnoff TimeLocal EchoRcr. Squelch TimeCxr. DetectLoad Compensation


Signal Flow Diagrams

Sequence of Events

• The Polling Data enters the Masters Main or Auxiliary Port and is then broadcast

to the remote modems over the fiber optics. • At each Remote FDM the Polling Data is past to the Main, Auxiliary and if

equipped, the FSK Ports. • Response Data entering the Remotes Main, Auxiliary and FSK Ports is

transmitted back to the Master Modem. • At the Master Modem, Response Data from the Remotes is passed to the Masters

Main and Auxiliary Ports and back to the Servers.

FDM-FSK FDMSeries

FSK 2 or 4 WireMain Port

Aux-Port

Main Port

Aux-Port

FDMMain PortFiber Optics

Aux-Port

TMC or Street Master Remote ControllerLocation

Remote ControllerLocation

Series

FDM2SAFDM170FDM2070FDM-SSRFDM-FiberHub

Main Server

Back-up Server


Data Port Flow Diagrams

1. Normal Operation at a Controller Location. (Aux Port switched to Normal Mode DCE)

This dual ports allows the Main Port to be connected to Local Controller, while the Auxiliary Port can be connected to another modem such as a Spread Spectrum Radio (DCE), while the FSK port drives the 2 or 4Wire system.

Mounting Options The modem has several versatile mounting options, it can be shelf mounted as a Stand Alone, or hang on a cabinet wall utilizing a pair of “Keyhole” slots. Both sides have pairs of keyhole slots for left or right wall mounting so as to maintain the desired front or rear panel view, hole centers are at 7.5inches.

DTEAux.Port DCE

AB Fiber

LinesData Flow

3 TXD

6 TXD

2 RXD

5 RXD

7 RTS

8 RTS

8 CTS

7 CTS

Main Port (DB9F)

Aux Port (RJ45)

LocalController

(DTE)

SpreadSpectrum

Radio

IFC-AXXXXX

IFC-AXXXXX

Com

mon

Func

tion

FDM-FSK DCE Operation

Data PortsFiber Optics

FDM

1 DCD

2 KODRTS

+ 5V

In

Out

FSKData Flow

KODRTS (DCD)

2W4Wire

FDM Data Ports

FSK Audio

To Master viaFiber Optics

FSKRemoteModems


Setting up the Modem

Configuring the FDM-FSK Modem

You must configure the modem to your system requirements by using the DIP Switches located on the bottom of the modem. Basically you will be selecting:

FDM (Optical Modem) • Master or Slave • Aux-Master • Fiber Topology • RS232 or RS485 • Baud Rate • Parity – None, Odd or Even • RTS On or Off • RTS Delay • Anti Streaming On or Off • Anti-Streaming Delay Times • Aux-Port DCE or DTE

FSK Modem • Full or Half Duplex • RTS to CTS Delay • Carrier Turn Off Time • Local Echo • Receiver Squelch Time • Carrier Detect • Load Compensation It is suggested that you first configure the FDM Modem and then configure the FSK Modem.


Parity NoneOdd Even


248

1832 64 Off

Aux.Port DCE DTE

MasterAux. Master

2 RingsDaisy Chain

RS232120024009600


115.2Kbts


Data Port Pinouts

RS-232 RJ45

Auxiliary

1 8

2 DCD4 GND5 RXD

6 TXD7 CTS8 RTS


DCDRXDTXD

GND


PINS 4-6-9

MainRS-232 Female

15

69

FullDuplex

12ms 6ms10ms 5ms


Hi 600 Ohms

Switch Actuator

HalfDuplex



Configuring the FDM Modem Section

FDM DIP Switches

Master/Slave. The modem at the “Head End” or “TMC” that connects into the fiber system defines that it will be set as a Master, all other modems shall beset as slaves.

Auxiliary Master Selection

This switch selection is used for Alternate TMC Disaster Recovery scenarios. Typically a city works yard would have an Emergency TMC, it is here that the local modem would be set as an Auxiliary Master. Should a failure occur at the Primary Master location, the Auxiliary Master will automatically take over the operation of the fiber system, then automatically hand back control when the Primary TMC is back on line.

Topology Selections Please note that you can have any combination of the following topologies, just mix or match, see Fiber Applications on page 21 for examples.

1. 2 Rings (Self Healing Dual Counter Rotating Rings) This selection provides the best fault tolerant protection.

2. 1 Ring

This selection is used when there is only one spare fiber left to form a Single Ring

3. Daisy Chain This selection is for the classic Daisy Chain, leave the previous switch set to 2 Rings.

1 Ring2 Rings

1 RingRing

2 RingsDaisy Chain

SlaveMaster

OffAux. Master


Data Protocol RS232/422

Select RS232 when connecting to traffic controller or other devices utilizing a RS232 port. RS422 is used to drive longer distances than RS232 over 2 pairs of balanced transmission lines .

Baud Rates

The selectable Baud Rates are, 1200, 2400, 9600, 19.2Kbt/s, 38.4Kbt/s, 57.6Kbt/s and 115.2Kbt/s.

Parity

Parity can be set for None, Odd or Even. Switch settings shown are Parity enabled and Even selected. For no Parity select None.

RTS/CTS Handshaking

When Handshaking is turned Off, data arriving at either data port from the attached devices will be transmitted over the fiber. When Handshaking is turned On and RTS is high or raised, data arriving at either data port from the attached devices will be transmitted over the fiber. When RTS is low no data will flow

CTS Delay

The RTS to CTS delay can be set at 0ms or 8ms, 0ms is for fast operation and 8 ms is used for external transmission systems that require a delay.

OffOffOffOffOffOffOff

24009600

38.4Kbts57.6Kbts

1200

19.2Kbts

115.2Kbts

Parity NoneOdd Even

RTS-CTS Off

CTS-0ms 8ms

RS422RS232


Anti- Streaming Anti-Streaming times 2, 4, 8, 16, 32, and 64 seconds, all are switch selectable and are additive to a maximum of 126 seconds.

When RTS is raised the anti-streaming countdown timer starts, at its conclusion the data to fiber path is inhibited and latched in an open state, CTS is then lowered and the anti-streaming Alarm LED is lit.

Should RTS be lowered the system will automatically reset but the anti-streaming alarm will remain lit indicating data timing violations from the attached controller. If the front panel anti- streaming RESET switch is momentary pushed, the system will automatically reset and the alarm LED will extinguish.

Auxiliary Port DCE/DTE Options

The FDM-FSK is primarily designed for Slave applications, therefore this selection is left in the DCE mode.

Optical Dynamic Range

For any system to work reliably there must be adequate signal level at the receiver. The modem must have a larger Dynamic Range, expressed in db, than the cables end to end attenuation (db). All Singlemode FDM series have 25DB of dynamic range.

Steps necessary to determine reliable operation,

1. Determine if your fiber is Multi-Mode or Single Mode. 2. Using an Optical Power Meter measure the End to End Attenuation of

your fiber pair, including all patchcords at the operating wavelength. 3. Add a minimum of 3db safety margin to this figure. 4. The Dynamic Range must be larger than the overall attenuation obtained

in step 3 for reliable operation.

Mode Operating Wavelength Dynamic Range Model # Singlemode 1300nm SM Laser 25db FDM Series

Ant-Strm Off248

1832

C-Mast 64 Off

DTEAux.Port DCE


Fiber Identification Techniques This method assumes the technician is dealing with the worst case i.e. no fibers are assigned or labeled at each modem location, just patchcords. Let’s assume that we are installing a Daisy Chain down an arterial roadway, at each end of the system you will have only two fibers, at all locations in between there will be four fibers, two from downstream and two from upstream, all modems are powered off.

1. Starting at the Master location (City Hall) power up the modem and connect the two fibers into T1 and R2.

2. At the next location power up the modem and connect each patchcord, one at time, into R2. When the modems display indicates “1”, insert this fiber into R1.

3. The remaining three patchcords are then rotated through T2 until you see the:

a. Daisy Chain display,

b. Or if you have the Slave set to 2 Rings you will

see a Fold-Back display.

You will now have Fiber communications with City Hall Note: City Hall will also have the Daisy Chain Display, if it was set to 2

Rings then it will have a Fold-Back display.

4. Continue steps 2 and 3 until you reach the end of the Daisy Chain.

T1

R2

R1

T2

LOS

LOS

Slave 1

T1

R2

R1

T2

LOS

LOS

Slave 1

T1

R2

R1

T2

LOS

LOS

Slave 1

T1

R2

R1

T2

LOS

LOS

Master

T1

R2

R1

T2

LOS

LOS

Master

T1

R2

R1

T2

LOS

LOS


Fiber Applications

Self Healing Dual Counter Rotating Ring Operation

This format requires that two fibers to be connected from modem to modem until a dual counter-rotating ring is formed. The advantage of this format is that if there is a fiber cut between any modems or a modem failure, the adjacent modems straddling the malfunction will automatically fold back into Ring 2 causing the system to self heal by forming a new ring. See Foldback illustration on the next page.

Modem DIP Switch Settings for 9600 8N1

The Dip Switch settings listed below show what would be required to set the modems to operate at 9600baud 8N1, this is a typical setting for the traffic industry, all other switch positions not shown are in the Off position or “other selection”.

Master Modem Slave Modem

Master Slave 2 Rings 2 Rings RS232 RS232 9600 9600 None (Parity) None (Parity) RTS/CTS RTS/CTS CTS-0ms CTS-0ms Off Anti-Stream 2 Seconds Aux Port Normal Aux Port Modem

R1

T1

T1

T1

T1

R1

R1

R1

FDM Slave 1

FDM Slave 2

FDM Slave 3

TMC Computer

RTU / Controller

Dual Counter Rotating Ring

Format

RTU / Controller

RTU / Controller

FDM Master

R2

R2

R2 T2

T2

T2

T2

R2

RING 1

RING 2


Foldback Condition

Under normal conditions all the modems would have a static display showing a two-ring operation.

With a failure of any Slave or a cable cut, the adjacent modems would fold back to form a new ring, thus maintaining communications. Next a message is sent to all the other modems in the system to flash their displays once a second to indicate a ring fold-back has taken place. The above diagram shows a catastrophic event at Slave 2, with the resulting graphics displays below.

R1

T1

T1

T1

T1

R1

R1

R1

FDMSlave 1

FDM Slave 3

DATA

See Ring StatusDisplays Below

R2

R2

R2 T2

T2

T2

T2

R2

RING 1

RING 2RTU /

Controller RTU /

Controller

TMCComputer

FDM Master

RTU /Controller

FDMSlave 2

T1

R2

R1

T2

LOS

LOS

NormalFiber Status

T1

R2

R1

T2

LOS

LOS

Slave 3

T1

R2

R1

T2

LOS

LOS

T1

R2

R1

T2

LOS

FDMMaster Slave 1

Fold-Back indication Indicates “Fiber Communications”are good in this segment.

Fold-Back indication


R1

T1

T1

T1

T1

R1

R1

R1

FDM Slave 1

FDM Slave 2

FDM Slave 3

TMC Computer

DATA

RTU / Controller

Single Fiber Loop

RTU / Controller

RTU / Controller

FDM Master

Single Ring Operation

This configuration is useful when there is only one fiber available from modem to modem, it has the lowest security of all configurable systems, should the ring be broken then the system will collapse.

Modem DIP Switch Settings for 9600 8N1 The Dip Switch settings listed below show what would be required to set the modems to operate at 9600baud 8N1, this is a typical setting for the traffic industry, all other switch positions not shown are in the Off position or “other selection”.


Master Slave 1 Ring 1 Ring RS232 RS232 9600 9600 None None RTS/CTS RTS/CTS CTS-0ms CTS-0ms Off Anti-Stream 2 Seconds Aux Port Normal Aux Port Normal


Single Ring Display

In the Single Ring mode, all the displays will be static until there is a break in the ring, when this condition occurs all displays will flash, the modem that has lost it’s input will flash a Loss Of Signal alarm (LOS) The following displays indicate a progressive build out of a Single Ring.

T1R1LOS

T1R1LOS

T1R1LOS

T1R1LOS

T1R1

LOS

T1R1LOS

T1R1LOS

T1R1

LOS

T1R1LOS

Master

Master

Master

Master

Slave 1

Slave 1 Slave 2

Slave 1 Slave 2

T1R1LOS

Slave 1


Point to Point Operation

a) Point to Point with No Redundant Fiber Path

In this situation we only have two fibers available, so we create a single ring, all operations and indications will be the same as the previous single ring setup.

Modem DIP Switch Settings for 9600 8N1 The Dip Switch settings listed below show what would be required to set the modems to operate at 9600baud 8N1, this is a typical setting for the traffic industry, all other switch positions not shown are in the Off position or “other selection”.


Master Slave 1 Ring 1 Ring RS232 RS232 9600 9600 None None RTS/CTS RTS/CTS CTS-0ms CTS-0ms Off Anti-Stream 2 Seconds Aux Port Normal Aux Port Normal

FDM Master Modem

FDM Slave

Modem Host

Computer TMC

RTU /

Controller

T1

T2 R2

R1 T1 R1

T2 R2

Data Data

Fiber Path


b) Point to Point with Redundant Fiber Path

The above shows a single Point to Point System with fail safe redundant fiber optics, if the primary path fails then the system will automatically run on the secondary (redundant) path. The best system security is obtained by running two separate cables following different paths, one cable has T1/R2 fibers and the other has R1/T2, if one cable is completely severed the system will automatically recover via the other cable.

Modem DIP Switch Settings for 9600 8N1

The Dip Switch settings listed below show what would be required to set the modems to operate at 9600baud 8N1, this is a typical setting for the traffic industry, all other switch positions not shown are in the Off position or “other selection”.

Master Modem Slave Modem Master Slave 2 Ring 2 Ring RS232 RS232 9600 9600 None None RTS/CTS RTS/CTS CTS-0ms CTS-0ms Off Anti-Stream 2 Seconds Aux Port Normal Aux Port Normal

FDM Master Modem

FDM Slave

Modem Host

Computer TMC

RTU /

Controller

T1

R2 T2

R1 T2 R2

R1 T1 Cable 2

Data Data

Cable 1

Fiber

T1

R2

R1

T2

LOS

LOS

Fiber Status

Normal

T1

R2

R1

T2

LOS

LOS

Fiber Status

Normal


Status Display

A failure of any receive fiber would cause the following fold-back indication to be displayed.

T2 T1R2

R1

T2 T1R2

R1 T2

T1 R2

R1

T2T1 R2

R1

T2 T1R2

R1 T2

T1 R2

R1

T2 T1R2

R1 T2

T1 R2

R1

LOS

LOS

LOS

LOS

T1

R2

R1

T2

LOS

LOS

Fiber Status

Normal

T1

R2

R1

T2

LOS

LOS

Fiber Status

Normal


Daisy Chain Operation

a) Single String Daisy Chain

This configuration is used when there is no fiber ring available, only one pair of fibers available from controller to controller, a typical application would be a TMC feeding an arterial string and terminating at the far end. Note: This configuration has no redundant path, any failure along the string will

cut off all down stream communications past the point of failure.

Modem DIP Switch Settings for 9600 8N1 The Dip Switch settings listed below show what would be required to set the modems to operate at 9600baud 8N1, this is a typical setting for the traffic industry, all other switch positions not shown are in the Off position or “other selection”. Note:

• Anti-Streaming is “always off” at a Master, optional for all Slave Modems.

Master Modem Middle Slaves End Slave

Master Slave Slave Slave 2 Ring 2 Ring 2 Ring 2 Ring Daisy Chain * Ring Ring Daisy Chain * RS232 RS232 RS232 RS232 9600 9600 9600 9600 None None None None RTS/CTS RTS/CTS RTS/CTS RTS/CTS CTS-0ms CTS-0ms CTS-0ms CTS-0ms Off Anti-Stream Anti-Stream Anti-Stream N.A. 2 Seconds 2 Seconds 2 Seconds Aux Port Normal Aux Port Normal Aux Port Normal Aux Port Normal

T1 FDM

Master

R2

TMC Computer

DATA R1

FDM Slave 1

RTU / Controller

T1

R2 T2

RTU / Controller

FDM Slave 2

FDM Slave 3

RTU / Controller

T1 R1 R1

R2 T2 T2


Status Display

Normal Fiber Indication (No Flashing Displays)

Note: To visually indicate the start and end of a Daisy Chain, set the “end” modems to Daisy Chain, this also turns off the LOS indication for the unused receiver’s R1 and R2. Set all other modems to 2 Ring only.

Fiber Alarm Notification (All Displays Flashing)

Next we show a cable cut anywhere in the mid span Slaves, this results in isolating the down stream modems from the polling Master. Note the LOS alarms on the modems adjacent to the cut, this indicates that the break is between the two modems, also note the “fold-back symbol” indicates the modem has communications to its adjacent modems but not across the break. The down-stream isolated modems are in communications with each other and will automatically come back on line when the break is repaired.

T1

R2

R1

T2

LOS

LOS

Middle Slave (s)

T1

R2

R1

T2

LOS

LOS

T1

R2

R1

T2

LOS

LOS

End Slave

T1

R2

R1

T2

LOS

LOS

FDMMaster Middle Slave (s)

1 RingRing

2 RingsDaisy Chain

1 Ring2 Rings

T1

R2

R1

T2

LOS

LOS

Middle Slave (s)

T1

R2

R1

T2

LOS

LOS

T1

R2

R1

T2

LOS

LOS

End Slave

T1

R2

R1

T2

LOS

LOS

FDMMaster Middle Slave (s)

Indicates “Fiber Communications” aregood on this segment.

Fold-Back indicationIndicates “Fiber Communications” are

good on this segment.


T1 R1 End Slave

RTU / Controller

Master Middle Slave(s)

End Slave

RTU / Controller

RTU / Controller

T1 T1 R1 R1

R2 R2 R2 T2 T2 T2

TMC Computer

DATA

Dual Daisy Chains (Center Master)

The “Center” Master Modem can be located anywhere in the Daisy Chain. In some scenario’s, the TMC may not be at the beginning, but somewhere in the “middle” of the arterial daisy chain. The above layout shows how to connect modems to both sides of the master.

Normal Fiber Indication( No Flashing Displays)

Note at the Master Modem you need to switch it to “Center Master” by selecting C-Mast 64 as well as Daisy Chain. Anti- Streaming is not used at a Master location.

End Slave Master Modem Middle Slaves End Slave Modem Slave Master Slave Slave 2 Ring 2 Ring 2 Ring 2 Ring Daisy Chain * Daisy Chain * Ring Daisy Chain * RS232 RS232 RS232 RS232 9600 9600 9600 9600 None None None None RTS/CTS RTS/CTS RTS/CTS RTS/CTS CTS-0ms CTS-0ms CTS-0ms CTS-0ms Anti-Stream Off Anti-Stream Anti-Stream 2 Seconds C-Mast 64 * 2 Seconds 2 Seconds Aux Port Normal Aux Port Normal Aux Port Normal Aux Port Normal

T1

R2

R1

T2

LOS

LOS

Middle Slave (s)

T1

R2

R1

T2

LOS

LOS

T1

R2

R1

T2

LOS

LOS

End Slave

T1

R2

R1

T2

LOS

LOS

FDMMasterEnd Slave


Configuring the FSK Modem Section

First a Primer on Frequency Shift Keying Modems The term Modem is a combination of two words, Modulator and Demodulator. Modem Frequency Shift Keying (FSK) Modems are designed to convert digital data to tone frequencies, this process is called modulation. The frequencies can easily be transmitted via a communication line to the receiving modem. At the opposite end of the communication line the tone frequencies are converted back to digital data by a process known as demodulation. By using this mechanism, two digital devices, such as Traffic Maintenance Center’s (TMC) Computer and a Remote Controller can communicate with each other via the outside cable plant. The 4xx series of modems use a modulation technique known as Frequency Shift Keying (FSK). Digital information is binary in format: that is, data is represented by either logic high or logic low (1 or 0). Communications terminology refers to logic Low as Mark and logic High as a Space. FSK Modems utilize this fact and generate a unique frequency for each logic level. Each model in the 4xx series have their own unique set of frequencies due to the baud rate therefore only modems of the same model number can communicate with each other, see the following chart. The rate at which the communication line changes state is known as the baud rate, this can be interpreted to be equivalent of bits per second. The 4xx Series of Modems are capable of communicating at baud rates up to 19200Kbts depending on the model.

Model # RS232 Input/Output 400 496 419

Baud Rate 1200 9600 19200 Mark Frequency Low (0) 1200Hz 11200Hz 19200Hz Space Frequency High (1) 2200Hz 17600Hz 38400Hz Soft Carrier 900Hz 7800Hz 13800Hz

Modulator DemodulatorTransmit Cable Pair

Digital Tones Digital

Transmit Section ofModem 1

Receive Section ofModem 2


Communications Sequence of Events For ease of understanding this sequence of events we will limit our discussions to one modem at the TMC and one Remote modem connected to a Controller over a 4 wire system. Note; Transmit and receive pairs are referenced to the “Master” end of a 4 wire circuit, also a modem has a Transmit Section and a Receive Section.

The Pole

1. The TMC computer (Master) signals the modem that it wants to transmit data by raising Request To Send (RTS) at the modems input. The modem returns a Clear To Send (CTS) back to the TMC computer after a time delay (user selectable). This is called Handshaking. As soon as the “master” modem sees RTS it transmits a Mark tone down the copper wire to wake up the remote modem.

2. The Remote Modems Carrier Detect (CD) circuit sees the Mark tone. If

the tone is continuous for 4 or 8ms (user selectable) the Carrier Detect circuit will validate it and unlock the receivers output (removes Receiver Squelch) and raise CD at the data port. This CD signal advises the Controller to expect data. The demodulated Mark tone, logic 0, is passed to the RS232 Data port, where it does not change state due to the fact that when not in use it is always at logic 0, same as the transmit end. Now let’s go back to the TMC end.

3. Once the TMC computer receives CTS (clear to send) it will send data to

the modem. At this juncture both modems on the system are in a “go” state.

4. The TMC computer now sends data (0’s and 1’s) to the modem which

converts it to Mark and Space frequencies. These frequencies (tones) are then transmitted down one pair of wires known as the transmit pair to the Remote modems receiver. When the data ends, RTS is lowered and the modem transmits a short burst of Soft Carrier (tone is out of band of the Mark/Space frequencies). This lower frequency tone causes the receiving modem to squelch the input to the digital circuits. This action “closes the modems door” to prevent noisy lines from false triggering the data circuits. The modem is now quiet.

5. We have now completed the Polling phase.

RTS

CTS

DATA

TMCComputer“Master”

TransmitSection

ReceiveSection

DATA

CD

RemoteControllerTransmit Pair


The Response

1. The Controller recognizes its address and prepares a message to be sent back to the TMC computer. Our response message will be sent back to the TMC on the Receive Pair of the 4wire system.

2. The Controller (Remote) signals the modem that it wants to send data by

raising Request To Send (RTS) at the modems input. The modem returns a Clear To Send (CTS) back to the Controller after a time delay (user selectable). This is called Handshaking. As soon as the “remote” modem sees RTS it transmits a Mark Tone down the copper wire to wake up the “Master” modem.

3. The TMC Modem’s Carrier Detect (CD) circuit sees the Mark tone. If the tone is continuous for 4 or 8ms (user selectable) the Carrier Detect circuit will validate it and unlock the receivers output (removes receiver squelch) and raise CD at the data port. This CD signal advises the TMC computer to expect data. The demodulated Mark tone, logic 0, is passed to the RS232 Data port, where it does not change state due to the fact that when not in use it is always at logic 0, same as the Controller end. Now let’s go back to the Controller end.

4. Once the Controller receives CTS (clear to send) it will send data to the

modem. At this juncture both modems on the system are in a “go” state.

5. The Controller now sends data (0’s and 1’s) to the modem which converts it to Mark and Space frequencies. These frequencies (tones) are then transmitted down the receive pair of wires to the TMC modems receiver.

6. At the TMC modems receiver the Mark and Space frequencies are

demodulated into 0’s and 1’s respectively. This is the same bit pattern that the Controller sent to the modem for transmission. This data is then sent to the TMC computer via the communication port. When the data ends, RTS is lowered and the modem transmits a short burst of Soft Carrier (tone is out of band of the Mark/Space frequencies). This lower frequency tone causes the receiving modem to squelch the input to the digital circuits. This action “closes the modems door” to prevent noisy lines from false triggering the data circuits. The modem is now quiet.

7. We have now completed the Response phase.

RemoteController

TransmitSection

ReceiveSection

TMCComputer Receive Pair

CD

DATA

RTS

DATA

CTS


Front, Rear and Bottom Panels

2/4 Wire FSK Display

This section displays the activity of data through the FSK Modem.

Carrier Detect (CD) LED This indicates the modem has detected a carrier tone from a remote modem on the 2/4 Wire circuit.

Request To Send (RTS) LED This indicates the Fiber Optic modem has asserted RTS to the FSK modem.

Clear To Send (CTS) LED This indicates the FSK modem has asserted CTS to the Fiber Optic Modem.

Transmit Data (TXD) LED

This indicates data is being transmitted from the Fiber Optic modem to the FSK Modem.

Receive Data (RXD) LED This indicates data is being received from the FSK Modems 2/4 Wire circuits

Key On Data (KOD) This indicates Data from the fiber is asserting (Keying) the FSK Modem’s RTS.

Rear Panel

Copper (FSK)

This is where the modem connects to the private wire metallic pairs, generally referred to as “copper”. The modem can operate in either 2 wire or 4 wire duplex modes. Note that in 2 wire operation the cable pair is connected to the “OUT” terminals on all modems.

OutIn

4W FSK2W

Copper

CD

RTS

2/4 Wire FSKKOD

CTS

TXD RXD


Bottom Panel

Dip Switches

Full Duplex or Half Duplex The first two switches select whether the modem operates in Full Duplex (4 Wire) or Half Duplex (2 Wire) mode.

RTS to CTS Time The delay time between the received RTS and the modems CTS response can be set to 12 or 6 ms.

Carrier Turn Off Time How long the carrier stays on after RTS is lowered.

Local Echo Select OFF for Full Duplex and On for Half Duplex.

Receiver Squelch Time The length of time which the Soft Carrier detector has before disabling the receivers output to the digital circuits; this can be set to 6 or 3ms.

Carrier Detect The length of time after carrier has been detected before enabling the receivers output to the digital circuits; this can be set for 8 or 4ms.

Load Compensation Normally this is set to 600 Ohm to match the line impedance. Switching to High increases the gain of the receiver and is only used when the receive signal is so low it causes data errors.


Parity NoneOdd Even


248

1832

64 OffAux.Port DCE DTE

MasterAux. Master

2 RingsDaisy Chain

RS232120024009600


115.2Kbts


Data Port Pinouts

RS-232 RJ45

Auxiliary

1 8

2 DCD4 GND5 RXD

6 TXD7 CTS8 RTS


DCDRXDTXD

GND


PINS 4-6-9

MainRS-232 Female

15

69

FullDuplex

12ms 6ms10ms 5ms


Hi 600 Ohms

Switch Actuator

HalfDuplex



FSK Applications Half Duplex Operation (2 Wire ‘One Pair’)

In this mode the transmit path (Poll) is shared with the receive path (Response) so only one modem can be on the line at same time. The remote modems have to wait until the FDM-FSK modem has stopped transmitting before it can send a message back; therefore it is important to slow things down by setting the modems timing parameters to the longest times. This will result in a slower turn around time for the system. All modems on the 2 wire pair should be set with the same timing plan so as not to step over each other. Note that all 2 wire connections are made only to the OUT terminals on all modems. To shorten up this round trip delay time and therefore speed up the system response it is necessary to go to a 4wire operation (next page)

The DIP Switch diagram shows where the adjustments are made to operate in either 2 or 4 wire mode. The settings shown here are for 2 Wire which is Half Duplex operation; note you may change various timing parameters to better suite your systems requirements. KOD internal jumper J5 must be “ON”. This is confirmed when the front panel KOD LED is lit or flashing, see page 44 for details.

OUT

IN

OUT

IN OUT IN

PollResponse

PollResponse

FSK

4xxSAModem

4xxSAModem

Fiber Trunk

Fiber Trunk

T1R2

T2 R1

FDM

(Full) Off


FullDuplex

12ms 6ms10ms 5ms

On (Half)6ms 3ms8ms 4ms

Hi 600 Ohms

Switch Actuator

HalfDuplex


Full Duplex Operation (4 Wire ‘2pairs’)

4-WIRE FULL DUPLEX systems use 2 pairs of wires to interconnect the Master and Slave Controllers. One pair carries data from the Master to the Local Controllers and the second pair carries data back from the Local Controllers to the Master. The far end modems do not have to wait till the master has completed its message before it starts to respond, therefore faster turn around times can be achieved. The Poll AUDIO OUT from the FDM-FSK connects to the Local’s AUDIO IN.

The Response AUDIO OUT from the Locals connects to the FDM-FSK AUDIO IN.

The DIP Switch diagram below shows where the adjustments are made to operate in the 4 wire mode. The settings shown here are for 4 Wire which is Full Duplex operation; note you may change various timing parameters to better suite your systems requirements. KOD internal jumper J5 must be “ON”. This is confirmed when the front panel KOD LED is lit or flashing, see page 44 for details.

OUT IN OUT IN4xx

Modem4xx

Modem

IN

OUT

FSK

Fiber Trunk

Fiber Trunk

T1R2

T2 R1

FDMPoll

Response

(Full) Off


FullDuplex

12ms 6ms10ms 5ms

On (Half)6ms 3ms8ms 4ms

Hi 600 Ohms

Switch Actuator

HalfDuplex


A Word on Dynamic Range All Model 4xx series modems have 42db of dynamic range based on a 0dBm transmit level into a 600 Ohm load.

How far will the signal go?

This is a not an easy one to answer and can only be generalized as many factures come into play such as;

1. Condition of the cable, water penetration, corrosion etc. 2. The wire gauge, larger is better. 3. The number of modems attached to the cable pair, as you add more

modems the resulting load impedance presented to the transmitting source will decrease across the cable pair. This will cause the signal level to decrease to a point where there is insufficient signal level over induced noise to operate error free, thus limiting the transmission distance.

4. Cross talk from adjacent pairs, due to high levels or a short between adjacent pairs.

5. Induced noise due to poor grounding of the cable/cabinet. 6. Baud Rates, as the frequency goes up the transmission distance decreases,

1200 baud may go 20 miles while 19200 baud on the same cable pair will typically be less than 10 miles.

Pushing the Envelope (Making the Last Mile) Additional distance can sometimes be obtained by boosting the gain of the “last” modem on the line; this is achieved through a DIP switch and only affects this modem. This external DIP switch, marked Load Compensation, is located on the switch bank on the underside of the modem. Selecting HI will increase the gain of the modem and may give you that extra signal level to make that last mile. For normal operation leave the switch set to 600 ohms. Before installing any modem make sure that the cable pairs have Lightning Protectors installed at each modem location, please make sure that the protective device is grounded according to National Electrical Code.


Combined FDM-FSK APPLICATIONS

The FDM Series allows you to combine all fiber topologies, all controllers* and many legacy systems together in one polling scheme. * if your Polling Software permits.

Dai

syC

hain

TMC Master

T1

R2

R1

T2

T1

R1

R2

T2

FDMFSK

Series

North Arterial Daisy Chain

South Arterial Daisy Chain

Main Arterial-Dual Counter Rotating RingMain Arterial-Dual Counter Rotating Ring

LocalController

RS2

32

LocalController

RS2

32

LocalController

RS2

32

LocalController RS232

Dual Counter Rotating Ring Fiber FiberFDMSeries

T1

R1

R2

T2

FDMFSK

Series


T1

R2

R1

T2

FDM-FSKSeries

2 / 4 Wire FSK

2 / 4 Wire FSK

T1

R2

R1

T2

FDMSeries

RS2

32

SSRadio

SSRadio

LocalController

RS2

32

T1

R2

R1

T2FDM

Series

LocalController

RS2

32

T1

R2

R1

T2FDM

Series

LocalController

RS2

32

T1

R2

R1 T2

T1 R2

T2

R1FDM-FiberHub

Port C

Port D

Port

A

Port

B

Auxiliary

Main

Dual Ring, Daisy Chain, FSKand SS Radio Applications

Dai

sy

Cha

in

T1 R2

R1 T2

FDMSeries


FDM2SAFDM170FDM2070FDM-FSKFDM-SSRFDM-FiberHub

FDM Series

T1

R1

R2

T2

FDMSeries

LocalControllerRS232

2 / 4 Wire FSK

Dual Counter Rotating Ring


Fiber to Copper to Fiber --- Copper Bridge Application This application can be used for Emergency Restoration by utilizing the “old copper pairs” to bridge over a damage fiber cable, or just stitching things together.

Note the Master is at the start of the new fiber system

Copper to Fiber to Copper --- Fiber Bridge Application This application ties two legacy copper systems to the new fiber system.

Note the Master is at the start of the new fiber system

2 or 4 wire

OUTIN4xx

Modem

FSK

R1

T2FDM

T2

R1

FSK

T1

R2FDM FDM

SeriesFDM

Series

T1

R2

T1

R2

R1

T2

R1

T2OUTIN

4xxModem

Copper Bridge

FDM170FDM2SAFDM2070FDM-SSRFDM-FiberHub

FDM-FSK FDM-FSK

To TMC or Street Master

MasterSlave SlaveSlave

Fiber Fiber


2 or 4wire

Copper

T2

R1FDM

SeriesFDM

SeriesOUT IN4xx

Modem

FSK

T1

R2FDM

OUTIN4xx

Modem

FSK

R1

T2FDM

T1

R2

T1

R2

R1

T2

R1

T2

Fiber BridgeCopper


FDM-FSK FDM-FSK

2 or 4wire

Master

Slave

Slave Slave Slave


Fiber with Copper Branch --- Copper Tap Application A typical application would be a requirement to tie in a cross street copper circuit into the main fiber arterial system.

In this application the FDM-FSK is the “head-end or master” for the fiber to copper communications. The control of the FSK by the FDM can be set to operate according to your particular system requirements. 4 Wire Systems For faster response times you may set internal jumper JP5 to DCD “ON”, this will force the FSK Transmitter to be on all the time, this is normal for 4wire head-ends. 2 Wire Systems Because you have only one pair of wires that is time shared between transmit and receive transmissions you must set the jumper JP5* to KOD “ON”. When data is detected coming from the fiber, DCD (KOD) keys the 2 wire transmitter and broadcasts onto the copper pair. After the data stops, DCD is lowered which turns of the transmitter and the FSK modem goes into the receive mode. *Note: See page 43 for location of JP5

2 or 4 wire

FSK

R1

T2FDM FDM

SeriesFDM

Series

T1

R2

T1

R2

R1

T2

R1

T2

OUT

IN

4xxModem


FDM-FSK


Slave SlaveSlave

Fiber Fiber

IN

OUT

OUT

IN

4xxModem

FDMSeries

T1

R2

R1

T2

Slave

2 or 4 wire

Fiber Trunk


Factory Default Settings

The FDM is shipped from the factory with the following DIP Switch settings enabled. For obvious reasons the FDM baud rate will be set to match the FSK baud rate.

Pins Main Port DCE Data Flows Auxiliary Port DCE Data Flows

1 DCD Out NC 2 RXD Out DCD (KOD RTS) Out 3 TXD In NC 4 NC GND Common 5 GND Common RXD Out 6 NC TXD In 7 RTS In CTS Out 8 CTS Out RTS In 9 NC

FDM Anti-Streaming times are additive, e.g. 2 + 4 = 6 seconds (max. time 126 sec)


Parity NoneOdd Even


248

1832 64 Off

Aux.Port DCE DTE

MasterAux. Master

2 RingsDaisy Chain

RS232120024009600


115.2Kbts


Data Port Pinouts

RS-232 RJ45

Auxiliary

1 8

2 DCD4 GND5 RXD

6 TXD7 CTS8 RTS


DCDRXDTXD

GND


PINS 4-6-9

MainRS-232 Female

15

69

FullDuplex

12ms 6ms10ms 5ms


Hi 600 Ohms

Switch Actuator

HalfDuplex


FSK Anti-Streaming time is 8 seconds.


KOD Jumper

KOD Jumper must be “ON”(Factory Default) for Dynamic FSK operation

Auxiliary Ports Pin # 2 (DCD) has a dual function:

1. It can be set to +5Vdc; this is used to assert RTS on an attached modem. Use only at a 4W Master location, or two modems point to point 4W.

2. It can assert DCD dynamically before data, then de-assert DCD after data;

this is used to handshake the built-in FSK modem. Use at a 2W Master or 2 or 4W Slave location.

FiberOptics

FiberOptics

DIP Switches

JP 5Aux-Ports Pin 2 FunctionsDCD or KOD Selection

KOD “ON” =

DCD “ON” = +5V


GDI Communications LLC Technical Services Bulletin #1

CARE AND HANDLING PROCEDURES FOR OPTICAL CONNECTORS

Author TONY ILETT

Cleanliness Is Very Important When Handling Fiber Optics Specs of dust which are invisible to the human eye, oil or grease from fingers can contaminate the end surfaces of an optical connector and reduce it’s coupling efficiency to the point of causing a system to fail. To put things into perspective the end face of an optical connector is 2.5mm in diameter. In the center of this is our optical wave-guide or glass fiber; this has a diameter of 125 microns (125 millionth of a meter) and is about the size of a human hair. In the center of this glass fiber is an area called the Core, which in Multimode fiber is 50 or 62.5microns in diameter and is invisible to the naked eye, it is this core that carries our optical signal. As stated Multimode core diameters are usually 50 microns (Europe) or 62.5 microns (North America), but in the long haul, high bandwidth world of Singlemode fibers the core size is 80% smaller than the fibers diameter of 125 microns and measures less than 10 microns across! It should now be obvious that a spec of dust, invisible the naked eye, can prevent your communications system from working, so: ------ KEEP IT CLEAN! Materials needed to clean Optical Patchcords

1. Wet Method Typically these are lens grade tissue pre-moistened with a solvent that has a concentration of 90% or better of Isopropyl Alcohol and sealed in a foil sachet.

or A lens grade tissue, which is then moistened with 90% or better Isopropyl Alcohol. Do not use rubbing alcohol as this contains oil for lubrication and will leave a smear or film which will degrade the Optical Return Loss and also cause particulate matter to stick to it.

or Dry Method

This involves using a special device that looks like a small videocassette tape containing a paper like material instead of magnetic tape. The connectors ferrule is inserted into an opening and the tape is wound on thus polishing the end face. There are several versions of this device readily available from supply houses. Note: This only polishes the end surface and does not clean the ferrules cylindrical surface that contributes to axial alignment.


2. Air Duster

A can of compressed inert gas with a plastic extension tube. Make sure that any liquid propellant has been discharged from the tube before using on the optics.

3. Lint Free Tissues

Lint free tissues used to clean fiber optic surfaces. Does not introduce any contaminates. Always keep sealed in a Ziploc bag to avoid contamination when not in use. Do not re-use the tissue, discard it.

4. Dust Caps

A supply of Clean Dust Caps, note that there are two sizes, one for connectors, the other one is slightly smaller and is used for the optical ports on patch-panels and transmission devices. Store them in a Clean Zip-Lock Bag.

The following scenario outlines the steps taken when disconnecting and then re-mating one end of a Patchcord from an optical device, such as a patch-panel or transmission equipment. WARNING! Invisible Laser Energy Can Damage Your Eyes

• Do not look into the end of an Optical Connector that is attached to a

fiber, it may be emitting potentially harmful energy that can damage your eyes, first disconnect the other end or turn the power “Off” on the transmitting device.

• Do not look into the transmitting port of an Optical Transmitter with out

first turning the power “Off” to that device.

Note: Visible Red LED’s (820nm Multimode) are low power devices that can be viewed at a safe distance of two to three feet.

Disconnecting the Optical Connector

1. Any accumulation of dust that has settled around the optical connectors must first be removed by using short bursts of compressed air from the Air Duster. In high dust areas use pre-moistened tissues or lint free tissues moistened with alcohol to wipe off excessive dust and then use the Air Duster, this will reduce the possibility of dust contaminating the optical connector as well as the optical receptacle. Do not re-use a tissue, discard it.


2. Disconnect the optical connector and put a clean protective dust cap over the end. If you don’t have a dust cap use a clean Ziploc bag or worst case temporary suspend the connector in free air and make sure it does not touch any other surface. Do not leave the exposed receptacle without any protection; cap it with a clean dust cap!

Reconnecting the Optical Connector

1. Remove the dust cap from the end of the optical connector (if fitted) and store in a clean Ziploc bag for future use at this site.

Do not touch the ferrules surfaces with your fingers!

2. Using the Air Duster, use short bursts to clear any dust from the connector, particularly from the ferrule area.

3. Remove the Optic Prep Wipe from a sealed sachet and start the cleaning process.

Do not put the wipe down on any surface as this will contaminate it and render it useless. Using this clean pad, clean the end face of the ferrule and its circumference. Do not be afraid to apply pressure when cleaning, use the same pressure as if you were cleaning eyeglasses.

4. Using the Air Duster, use a single short burst to clean and dry the ferrule before

starting the re-connecting process. Do not touch the ferrule again as you might contaminate it.

5. Remove the dust cap from the mating receptacle and store in the clean Ziploc bag

for future use.

6. Hold the connector locking mechanism between thumb and forefinger. Allow the little finger to steady the hand by holding it against the chassis or patch-panel during the insertion process. With the little finger in contact with the panel, there is a reduced chance of the ferrule touching any contaminated non-mating surfaces.

7. Insert the ferrule into the receptacle and slowly rotate the connector until the key

aligns itself with the receptacles keyway, then push the connector home and engage the connectors locking mechanism. Do not force the connector; it should be a snug fit.


Contents of this user guide may not be copied or published without the written consent of GDI Communications LLC, Verdi, Nevada. The contents of this user guide are deemed to be correct at the time of publishing and are offered as a guide only; GDI Communications LLC is not liable for any inaccuracies or omissions.

fdm-fsk - gdi communications aug 06 fdm-fsk preliminary user guide dwg: a01230 fdm series of fiber...

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