Multi-Tech MultiFRAD FR111, MultiFRAD 100- Owner's Manual

Model FR1 1 1

Single Port Frame Relay
Access Device with 56K DSU

Owner's Manual

NOTE: This equipment has been tested and found to comply with the
limits for a Class B digital device, pursuant to Part 15 of the FCC Rules.
These limits are designed to provide reasonable protection against
harmful interference when the equipment is operated in a residential
installation. This equipment generates, uses and can radiate radio
frequency energy, and if not installed and used in accordance with the
instructions, may cause harmful interference to radio communications.
However there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference
to radio or television reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to correct the
interference by one or more of the following measures:

• Reorient or relocate the receiving antenna

• Increase the separation between the equipment and receiver.

• Connect the equipment into an outlet on a circuit different from
that to which the receiver is connected.

• Consult the dealer or an experienced raido/TV technician for

help.

Warning: Changes or modifications to this unit not expressly approved
by the party responsible for compliance could void the user's authority to
operate the equipment.

The CE mark is affixed to the enclosed MultiTech product to confirm
compliance with the following European Community Directives:

Council Directive 89/336/EEC of 3 May 1989 on the approximation of the
laws of Member States relating to electromagnetic compatibility;

and
Council Directive 73/23/EEC of 19 February 1973 on the harmonization

of the laws of Member States relating to electrical equipment designed
for use within certain voltage limits;

both amended by
Council Directive 93/68/EEC of 22 July 1993 on the harmonization of CE

marking requirements.

4

Owner's Manual

82067401 Revision B

MultiFRAD

TM

100-Series (Model No FR111)

This publication may not be reproduced, in whole or in part, without
prior expressed written permission from Multi-Tech Systems, Inc. All
rights reserved.

Copyright © 1998, by Multi-Tech Systems, Inc.

Multi-Tech Systems, Inc. makes no representations or warranties with
respect to the contents hereof and specifically disclaims any implied
warranties of merchantability or fitness for any particular purpose.
Furthermore, Multi-Tech Systems, Inc. reserves the right to revise this
publication and to make changes from time to time in the content hereof
without obligation of Multi-Tech Systems, Inc. to notify any person or
organization of such revisions or changes.

Record of Revisions

Revision Description

A Manual released. All pages at revision A.
(7/21/97)
B General Update. All pages at revision B.
(5/28/98)

Patents

This Product is covered by one or more of the following U.S. Patent
Numbers:

5.301.274; 5.309.562; 5.355.365; 5.355.653; 5.452.289;

5.453.986

. Other Patents Pending.

TRADEMARKS

Trademark of Multi-Tech Systems, Inc. are as follows: MultiFRAD

100

, and

the Multi-Tech logo.
Windows is a registered trademark of Microsoft.

Multi-Tech Systems, Inc.

2205 Woodale Drive

Mounds View, Minnesota 55112

[phone] or [phone]

Fax [phone]

Tech Support [phone]

BBS [phone] or [phone]

Internet Address: http://www.multitech.com

Fax-Back [phone]

5

Contents

Chapter 1 - Introduction and Description

1.1 Introduction................................................................................. 9

1.2 About This Manual ...................................................................1 0

1.3 A Typical Application ............................................................... 1 2

1.4 FCC Regulations for Telephone Line Interconnection ........... 16

1.5 Canadian Limitations Notice ................................................... 18

1.6 Specifications ........................................................................... 19

Chapter 2 - Front and Back Panel Descriptions

2.1 Introduction............................................................................... 23

2.2 Front Panel ............................................................................... 2 3

2.3 Back Panel ...............................................................................25

2.4 Switch Settings ......................................................................... 2 6

2.5 Shunts ....................................................................................... 2 7

Chapter 3 - Setup

3.1 Introduction............................................................................... 31

3.2 Unpacking ................................................................................31

3.3 Safety LWarnings ..................................................................... 3 1

3.4 Setup.........................................................................................32

3.5 V.35 Shunt ................................................................................ 3 4

Chapter 4 - Software Loading and Configuration

4.1 Introduction............................................................................... 37

4.2 Loading Software ..................................................................... 37

4.3 Configuring Your MultiFRAD using Windows ......................... 40

4.4 Configuring your MultiFRAD using a Dumb Terminal ............ 4 4

Chapter 5 - Software Utility Descriptions

5.1 Introduction............................................................................... 53

5.2 MultiFRAD Main Menu ............................................................. 53

5.2.1 Configuration ................................................................. 54

5.2.2 Others ............................................................................54

5.2.3 Download ...................................................................... 54

5.2.4 Exit ................................................................................. 54

5.2.5 Help ............................................................................... 5 5

5.2.6 MultiFRAD Version ....................................................... 55

5.3 Data Port Configuration ........................................................... 5 6

5.4 Trunk Configuration ................................................................. 62

5.5 Statistics.................................................................................... 66

5.6 Diagnostics............................................................................... 66

Chapter 6 - ASCII Terminal Menu System

6.1 Introduction............................................................................... 71

6.2 Configurations Menu ............................................................... 71

6.2.1 Async Data Port Configuration .....................................7 2

6.2.2 Sync Data Port Configuration ....................................... 7 5

6.2.3 Trunk Configuration ...................................................... 77

6.3 Statistics.................................................................................... 80

6.4 Reset Options ........................................................................... 8 2

6.5 Diagnostic Tests ....................................................................... 8 2

Chapter 7 - Service, Warranty and Tech Support

7.1 Introduction............................................................................... 87

7.2 Limited Warranty ...................................................................... 8 7

7.3 Tech Support ............................................................................ 8 7

7.3.1 Recording MultiFRAD Information ................................ 8 8

7.3.2 Service............................................................................ 89

7.4 About the Multi-Tech BBS ........................................................ 8 9

7.4.1 Logging on to the Multi-Tech BBS................................ 9 0

7.4.2 Downloading a File ....................................................... 90

7.5 About Compuserve .................................................................. 91

7.6 About the Internet ..................................................................... 9 2

7.7 About the Multi-Tech Fax-Back Service .................................. 92

7.8 Upgrading the Flash PROM..................................................... 9 3

Appendices

Appendix A - Cabling Diagrams ..................................................... 9 7

1

Introduction and

Description

8

9

1.1 Introduction

The Multi-Tech Systems MultiFRAD™ 100-Series, Model number FR111, is a
one-port Frame Relay Access Device (FRAD) with 56K DSU that
encapsulates non-packetized data from a serial device into frame relay
frames and is responsible for framing that data with header and trailer
information prior to transmission to a frame relay network. The Multi­FRAD allows a non-frame relay device to connect to a common carrier
frame relay network service or private frame relay network. The access
device is designed with an internal 56K Data Service Unit (DSU) that
allows a single frame relay permanent virtual circuit (PVC) to be
connected to a 56K DDS circuit. On the receiving end of the communi­cation link, the MultiFRAD serves to strip away the frame relay control
information in order that the target device is presented with the data
packaged in its original form.

The versatility of the MultiFRAD provides for a smooth integration with
existing equipment; e.g., multiplexers, routers, legacy equipment such
as cluster controllers, and asynchronous devices such as PCs running
remote control software. The non-frame relay device connects to the
data port on the back of the MultiFRAD and is capable of synchronous
data transmission up to 56K bps or asynchronous data transmission up
to 57.6K bps. The network connection is provided by the trunk port
which directly connects to the frame relay network.

Figure 1-1. MultiFRAD 100-Series

10

1.2 About This Manual

This manual describes the MultiFRAD, and tells you how to install and
configure the unit. The information contained in each chapter is as
follows:

Chapter 1 - Introduction and Description

Chapter 1 introduces the MultiFRAD 100-Series. A typical application
is presented with a discussion on ordering a frame relay line and how to
configure a MultiFRAD. A list of relevant specifications are provided at
the end of the chapter.

Chapter 2 - Front and Back Panel Descriptions

Chapter 2 describes the front panel indicators and back panel connec­tors. The front panel contains the LEDs for the data and trunk status.
The back panel provides cable connections to the data port, trunk port,
and a power connection for an external power supply.

Chapter 3 - Setup

Chapter 3 provides unpacking instructions, a setup procedure for
connecting cables and direction as to when you should configure the
unit. Also, after the unit is configured and if a V.35 interface is needed
for the data device, a procedure for changing the shunt to the V.35
position is provided.

Chapter 4 - Software Loading and Configuration

This chapter provides procedures on how to load the software utility and
configure the unit when a pc with a Windows application is connected to
the MultiFRAD. If a dumb terminal is connected to the MultiFRAD, the
unit can still be configured using the ASCII terminal menu system that is
present in the memory of the unit.

Chapter 5 - Software Utility Descriptions

This chapter provides a complete description of the Windows based
software used on the MultiFRAD 100-Series. From an icon in the
MultiFRAD program group, the Main menu is displayed. From the Main
menu, the data Port and trunk can be configured. Trunk statistics,
diagnostics, and the download feature are also described.

11

Chapter 6 - ASCII T erminal Menu System

Chapter 6 provides a description of the ASCII terminal menu system.
The ASCII terminal menu system is used when a dumb terminal is
connected to the data port. These menus allow you to configure the
data port and trunk, view statistics, reset the unit, and enable diagnos­tics.

Chapter 7 - Service, W arranty and Tech Support

Chapter 5 provides instructions on getting service for your MultiFRAD at
the factory, a statement of the limited warranty, information about our
user bulletin board service, and space for recording information about
your MultiFRAD prior to calling Multi-Tech's Technical Support. The final
three sections explain how to use our bulletin board service (BBS), and
get support through CompuServe and the Internet.

12

1.3 A Typical Application

A typical application for a MultiFRAD 100-Series is connecting a single
non-frame relay device to a frame relay network. The MultiFRAD 100­Series is usually used at a remote site where a single DLCI and a single
device needs to be connected to a frame relay network. A MultiFRAD
100-Series can connect any existing synchronous or asynchronous
non-frame relay device to a frame relay network.

Trunk

T1 DSU

Trunk

Host Site

Frame Relay
Network

17

16

26

27

T

e

c

h

Systems

®

Channel 1

Remote Site 2

Trunk

DTR

OH

Statistical Multiplexer

R
E
T
R
A
N
S
M
IT

1

2

3

BUFFER
FULLNESS
LEVEL

F
L
O
C
T
R
L
R
C
V

L
I
N
K
A
L
A
R
M

R
E
M
O
T
E
D
W
N

T
E
S
T

M
O
D
E

MultiMux

Internal Composite Link

MMH2834 CD RCV XMT CTS 28.8 24.0 19.2 14.4 OH TR EC DBUP
DSU CD RCV XMT CTS 56 19.2 RTS NS OOS TM
V29/V33 Modem CD RCV XMT CTS

External Composite Link

Channel TwoChannel Three Channel Four

Command Modem

Channel Five

Channel SixChannel Seven

Channel Eight

XMTRCV XMTRCV XMTRCV

A
S
Y
N
C
L
I
N
K

5
6
K
D
S
U

V
2
9
/
V
3
3

RCV

Channel one

RCV

XMT

CD
RCV

XMT

CTS

V.35

XMTRCV

XMT

RCVXMTXMTRCV

XMT

RCV

INTERNAL LINK DEVICE

(Modems)

Systems

MultiTech

M
M
H
2
8
3
4

CD

MultiMux

Data

Remote Site 1

Data

PC

PC

Channel 2

DTR

OH

Statistical Multiplexer

R
E
T
R
A
N
S
M
IT

1

2

3

BUFFER
FULLNESS
LEVEL

F
L
O
C
T
R
L
R
C
V

L
I
N
K
A
L
A
R
M

R
E
M
O
T
E
D
W
N

T
E
S
T

M
O
D
E

MultiMux

Internal Composite Link

MMH2834 CD RCV XMT CTS 28.8 24.0 19.2 14.4 OH TR EC DBUP
DSU CD RCV XMT CTS 56 19.2 RTS NS OOS TM
V29/V33 Modem CD RCV XMT CTS

External Composite Link

Channel TwoChannel ThreeChannel Four

Command Modem

Channel Five

Channel SixChannel Seven

Channel Eight

XMTRCV XMTRCV XMTRCV

A
S
Y
N
C
L
I
N
K

5
6
K
D
S
U

V
2
9
/
V
3
3

RCV

Channel one

RCV

XMT

CD
RCV

XMT

CTS

V.35

XMTRCV

XMT

RCVXMTXMTRCV

XMT

RCV

INTERNAL LINK DEVICE

(Modems)

Systems

MultiTech

M
M
H
2
8
3
4

CD

MultiMux

LAN 1
Ethernet Network

Ethernet

MultiFRAD 100

MultiFRAD 100

MultiFRAD II

Figure 1-2. T ypical Frame Relay Network

A MultiFRAD is easily connected to a frame relay network. One Data
Link Connection Identifier (DLCI) is required and it is provided by your
local network service provider when you request (subscribe) for a local
telephone line connection. When your local network service provider
engineers your connection, a virtual circuit is established between your
location and the destination of your connection. This virtual circuit is
called a permanent virtual circuit (PVC).

1.3.1 Ordering a Frame Relay Line

Ordering frame relay services from your local telephone company
involves connecting the physical line, defining the port connection,
configuring the PVC through the network, and assigning the Data Link
Connection Identifier (DLCI). The DLCI is a number between 16 and
1007 that identifies the PVC between your MultiFRAD and the phone
company's switch. The DLCI is assigned at the same time your local
service provider defines the permanent virtual circuit (PVC) that is the
path to your destination. When a PVC is assigned, an average guaran­teed throughput is negotiated with the service provider. The guaranteed
throughput is called committed information rate (CIR) and is based on

13

your capability to present data to the local telephone switch. Your
capability to present data is determined by the internal DSU (Data
Service Unit) that can transfer digital data at a maximum rate of 56,000
bits-per-second to the network. A general rule of thumb in this scenario
is to assign a CIR of 32K bps and an excess burst rate (Be) of 24K bps.
The sum of the CIR and Be can not exceed your capability to present
data to the network. Finally during subscription, the management type
is defined by the local frame relay service provider. The management
type is a mechanism for communicating the status of the PVC and is
dependent upon which type is running on the telephone switch. Three
types of management are supported by the MultiFRAD: local manage­ment interface (LMI), Annex A, and Annex D.

1.3.2 How to Configure a MultiFRAD

Configuring a MultiFRAD is a simple process of defining the data port
device and the trunk parameters for frame relay. To configure a Multi­FRAD, a pc has to be connected to the Data port on the MultiFRAD and
the MultiFRAD software loaded. To define the data port, the type of
device that is connected to it has to be defined. If the device is a
synchronous device such as a multiplexer, then the clocking and speed
of the device have to be defined in the Data Port Configuration dialog
box. A couple of other parameters also have to be set in order for the
multiplexer to communicate with the MultiFRAD.

If the data device is an asynchronous device, the Asynchronous Mode
option button changes the dialog box to display the asynchronous
parameters. The async parameters are the normal baud rate, word

14

length, parity, stop bits, and flow control. The Async Data Port Configu­ration dialog box displays the default parameters that may apply to a
majority async devices.

When the data device is defined, then the trunk configuration needs to
be defined. The trunk configuration is displayed in the Trunk Configura­tion dialog box. Most of the trunk information is supplied by your
network service provider.

For example, if the MultiFRAD at remote site 2 in our typical Frame
Relay network in Figure 1-2 is being configured, the DLCI is 26, the
Access Rate is 56000, and generally a Committed Info Rate of 32000
with a Excess Burst Rate (Be) of 24000 would allow the multiplexer at
remote site 2 to communicate with the host site. These parameters can
be added to the Trunk Configuration dialog box with a Management
Type defined by your network service provider, lets say for this example
that it is LMI. The default Management Parameters in the Trunk Configu­ration dialog box for the most part should work for this typical applica-

15

tion. The trunk configuration would be complete by clicking on the Save
button and returning to the Main menu. In the Main menu, click on the
download button to transfer the configuration to the MultiFRAD. Within a
few seconds the new configuration is downloaded to the MultiFRAD and
it is ready for operation.

16

1.4 FCC Regulations for Telephone Line Intercon­nection

1. This equipment complies with Part 68 of the FCC rules. On the
outside surface of this equipment is a label that contains, among other
information, the FCC registration number and ringer equivalence
number (REN). If requested, this information must be provided to the
telephone company.

2. As indicated below the suitable jack (USOC connecting arrange­ment) for this equipment is shown. If applicable, the facility interface codes
(FIC) and service order codes (SOC) are shown.

3. The ringer equivalence number (REN) is used to determine the
quantity of devices which may be connected to the telephone line.
Excessive RENs on the telephone line may result in the devices not
ringing in response to an incoming call. In most, but not all areas, the
sum of the RENs should not exceed five (5.0). To be certain of the
number of devices that may be connected to the line, as determined by
the total RENs, contact the telephone company to determine the
maximum REN for the calling area.

4. If this equipment causes harm to the telephone network, the tele­phone company will notify you in advance. But if advance notice isn’t
practical, the telephone company will notify the customer as soon as
possible. Also, you will be advised of your right to file a complaint with
the FCC if you believe it is necessary.

5. The telephone company may make changes in its facilities, equip­ment, operations, or procedures that could affect the operation of the
equipment. If this happens, the telephone company will provide ad­vance notice in order for you to make necessary modifications in order
to maintain uninterrupted service.

6. If trouble is experienced with this equipment (the model of which is
indicated below) please contact Multi-Tech Systems, Inc. at the address
shown below for details of how to have repairs made. If the trouble is
causing harm to the telephone network, the telephone company may
request you remove the equipment from the network until the problem is
resolved.

7. No repairs are to be made by you. Repairs are to be made only by
Multi-Tech Systems or its licensees. Unauthorized repairs void registra­tion and warranty.

8. This equipment cannot be used on public coin service provided by
the telephone company. Connection to Party Line Service is subject to
state tariffs. (Contact the state public utility commission, public service

17

commission or corporation commission for information.)

9. If so required, this equipment is hearing aid compatible.
Manufacturer: Multi-Tech Systems, Inc.
Model Number: MultiFRAD 100-Series
FCC Registration Number: AU7USA-24704-XD-N
Ringer Equivalence: N/A
Modular Jack (USOC) RJ48
Service Center in U.S.A. Multi-Tech Systems Inc.

2205 Woodale Drive
Mounds View, MN 55112 USA
[phone] or [phone]
U.S. Fax [phone]

18

1.5 Canadian Limitations Notice

Notice: The ringer equivalence number (REN) assigned to each

terminal device provides an indication of the maximum number of
terminals allowed to be connected to a telephone interface. The
termination of a interface may consist of any combination of devices
subject only to the requirement that the sum of the ringer equivalence
numbers of all the devices does not exceed 5.

Notice: The Industry Canada label identifies certificated equipment. This
certification means that the equipment meets certain telecommunica­tions network protective, operational and safety requirements. The
Industry Canada does not guarantee the equipment will operate to the
user’s satisfaction.

Before installing this equipment, users should ensure that it is permis­sible to be connected to the facilities of the local telecommunications
company. The equipment must also be installed using an acceptable
method of connection. The customer should be aware that compliance
with the above conditions may not prevent degradation of service in
some situations.

Repairs to certified equipment should be made by an authorized
Canadian maintenance facility designated by the supplier. Any repairs
or alterations made by the user to this equipment, or equipment
malfunctions, may give the telecommunications company cause to
request the user to disconnect the equipment.

Users should ensure for their own protection that the electrical ground
connections of the power utility, telephone lines and internal metallic
water pipe system, if present, are connected together. This precaution
may be particularly important in rural areas.

Caution: Users should not attempt to make such connections them­selves, but should contact the appropriate electric inspection authority,
or electrician, as appropriate.

19

1.6 Specifications

Data Port

• Single data port with synchronous or asynchronous data format

• Async data rate up to 57.6K bps or sync data rate up to 56K bps

• RS232C and ITU-T V.35 interface using an adapter cable

• Internal shunt plugs to configure RS232C or ITU-T V.35 interface

• Async data format of 5,6,7, or 8 bits; 1, 1½, or 2 stop bits; odd,

even, or no parity

• Sync data format is HDLC/SDLC

• Data port connector is a DB-25 female

Trunk

• Single trunk port with synchronous DDS or compatible data format

• Sync data rate of 56k bps

• DDS interface with an RJ-48 keyed jack

• Full duplex over LADS (Local Area Data Set) or two-pair non-

loaded metallic wire

Electrical/Physical/Environmental

• Voltage - 115v AC, 50/60 Hz

• Power - 2 watts

• Dimensions - 4.3" W x 1" H x 5.6" L

- 10.8 cm x 2.5 cm x 14.2 cm

• Weight - 8 oz. (224 g)

• Temperature - 32° to 120° F (0° to 50° C)

• Humidity - 20 - 90% non-condensing

Compatibility

• Link management via ANSI T1.617 Annex D, ITU-T Q.933 Annex A

or LMI

20

21

2

Front and Back

Panel Descriptions

22

23

2.1 Introduction

This chapter describes the front panel LEDs and back panel connectors.
The front panel has one row of LEDs for both the data channel and
trunk status. Two back panel connectors provide the data and trunk
connections. A circular power connector is provided to connect the
external power supply.

2.2 Front Panel

The front panel contains two sets of LEDs that provide the status of the
data and trunk connections. The data LEDs display the activity of the
data port, if V.35 interface signaling is used, and whether command
mode is active. The trunk LEDs display status whether the trunk is
transmitting or receiving frames, link status, and congestion.

Figure 2-1. Front Panel

Data

35 Lights when the data port is configured for a V.35

interface. That is, the data shunt is in the V.35 position.

CM Command Mode (CM) LED lights when the Data/

Command mode switch is in the Command mode
position and blinks when the unit is in test mode.

TD Transmit Data (TD) LED blinks when data is being

transmitted - on for a space and off for a mark.

RD Receive Data (RD) LED blinks when data is being

received - on for a space and off for a mark.

DSU

TD Transmit Data (TD) LED blinks when data is being

transmitted - on for a space and off for a mark.

RD Receive Data (RD) LED blinks when data is being

24

received - on for a space and off for a mark.

DSU Data Service Unit (DSU) LED lights when the unit is in

the DSU-only mode.

NS The No Signal (NS) LED lights when no signal is

received from the network or when the signal is too
weak for normal operation.

OOS The Out Of Service (OOS) LED lights when an outage

condition occurs. This happens when there is a failure
in the digital service that is detected by the network
and the telco sends a repetitive OOS sequence.

CD The Carrier Detect (CD) LED lights when a carrier

signal is received from the network.

Trunk

CN Congestion (CN) LED lights when congestion is

detected on the trunk.

LK Link (LK) LED blinks slowly when there is no link

management connection with the network. Blinks
quickly when link management is established with the
network. Remains solid ON when the network
indicates the PVC is active.

CD Carrier Detect (CD) LED lights when a carrier signal is

detected from the network.

TD Transmit Data (TD) LED blinks when data is being

transmitted - on for a space and off for a mark.

RD Receive Data (RD) LED blinks when data is being

received - on for a space and off for a mark.

25

2.3 Back Panel

The cable connections for the MultiFRAD are made at the back panel.
Two cable connections are provided and one power supply connection.
The Data connector allows the MultiFRAD to be connected to a non­frame relay device and the Trunk connector connects to a common
carrier frame relay network service or private frame relay networks. The
cable connections are shown in Figure 2-2 and defined in the following
sections.

Trunk

Data

Power

Figure 2-2. Back Panel

Power Connector

The Power connector is used to connect the external wall type trans­former power supply to the MultiFRAD. The wall transformer plugs
directly into an AC outlet.

Trunk Connector

The Trunk connector is used to connect the MultiFRAD to a 56K DDS
circuit that provides the local access to the frame relay service. This
connector is a RJ48-keyed jack on the back panel of the unit.

Data Connector

The Data connector is used to connect the MultiFRAD to a non-frame
relay device, such as, multiplexers, routers, or legacy equipment such
as cluster controllers, or an asynchronous device such as a PC running
remote control software. A second use of this connector is to configure
the MultiFRAD. The Data connector is a DB-25 female connector
located on the back panel of the MultiFRAD.

The Data connector interface can be either an RS-232C or V.35 inter­face. When the V.35 interface is used, the data shunt has to be moved
from the default RS232 position to the V.35 position. Refer to "Shunt" in
this chapter for changing the data shunt. Refer to Appendix A for
cabling requirements in V.35 mode.

26

2.4 Switch Settings

The 8-position DIP switch located on the right side of the MultiFRAD
only uses the first four positions. The DIP switches are shown in Figure
2-3 and their settings are described in Table 2-1.

DIP-Switches

Figure 2-3. Switch Settings

Table 2-1. Switch Settings

Switch Mode Position Description

1 Cmd/Data UP* Data

DOWN Command

2 Clocking UP* DDS

DOWN Internal

3 Loopback UP* Normal

DOWN Loopback

4 DSU UP FRAD

DOWN* DSU

5-8 Not Used

*Factory default setting

27

2.5 Shunts

V.35 signal levels are generally more reliable for high speed data and/
or longer cable distances. EIA-232D signal levels are intended for data
rates of 19,200 bps or less and cable lengths of 50 feet or less. For
higher speeds and/or longer distances, V.35 is generally preferred.

There are two shunt positions on the printed circuit board that configure
the data port for either RS232 or V.35 interface. Both DIP sockets for the
shunts are shown in Figure 2-4.

V.35 Shunt Position

RS232 Shunt Position

Figure 2-4. Shunts

In Figure 2-3, the shunt is shown in the RS232 (default) position (i.e., in
the right-hand DIP socket - the one closest to the DIP switches. To
change the location of the shunt, refer to the V.35 Shunt procedure in
Chapter 3.

28

3

Setup

30