Black Box MT210A User manual

JANUARY 1999
MT210A
Multiport CSU/DSU
Line
Quick-Connect Interface Module
OFF O Interface Port
ON I
Power
Local-
Control Port
Multiport CSU/DSU
2.4 kbps
4.8 kbps
9.2 kbps
19.2 kbps
38.4 kbps
56 kbps
64 kbps
TD
RD
RTS
CTS
DCD
DSR
DTR
No Signal
Error
Test Mode
Line Rate DTE Status Line
Status
Test Modes
Normal-
Remote-
-Errored
-Normal
-Off
Loop Pattern
CUSTOMER
SUPPORT
INFORMATION
Order toll-free in the U.S.: Call 877-877-BBOX (outside U.S. call 724-746-5500)
FREE technical support 24 hours a day, 7 days a week: Call 724-746-5500 or fax [phone]
Mailing address: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: [email protected]

1
MULTIPORT CSU/DSU
FEDERAL COMMUNICATIONS COMMISSION
AND
CANADIAN DEPARTMENT OF COMMUNICATIONS
RADIO FREQUENCY INTERFERENCE STATEMENTS
This equipment generates, uses, and can radiate radio frequency energy and if not
installed and used properly, that is, in strict accordance with the manufacturer’s
instructions, may cause interference to radio communication. It has been tested
and found to comply with the limits for a Class A computing device in accordance
with the specifications in Subpart J of Part 15 of FCC rules, which are designed to
provide reasonable protection against such interference when the equipment is
operated in a commercial environment. Operation of this equipment in a
residential area is likely to cause interference, in which case the user at his own
expense will be required to take whatever measures may be necessary to correct the
interference.
Changes or modifications not expressly approved by the party responsible for
compliance could void the user’s authority to operate the equipment.
This digital apparatus does not exceed the Class A limits for radio noise emission from digital
apparatus set out in the Radio Interference Regulation of the Canadian Department of
Communications.
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites
applicables aux appareils numériques de la classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par le ministère des Communications du Canada.
This equipment complies with the Electromagnetic Compatibility (EMC) directive
and the Low Voltage Directive (LVD) of the European Union (EU).

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MULTIPORT CSU/DSU
FCC REQUIREMENTS FOR
DIGITAL EQUIPMENT
1. This equipment complies with Part 68 of the FCC rules. The unit bears a
label that contains the FCC registration number. If requested, you must
provide this information to the telephone company.
2. This equipment contains an FCC-compliant modular jack. It is designed
to be connected to the digital telephone network or premises wiring
using compatible modular plugs and cabling that comply with the
requirments of FCC Part 68 rules.
3. In the unlikely event that this equipment causes harm to the telephone
network, the telephone company may temporarily disconnect your
service. The telephone company will try to warn you in advance of any
such disconnection, but if advance notice is not practical, it may
disconnect the service first and notify you as soon as possible afterwards.
If such a disconnnection is necessary, you will be advised of your right to
file a complaint with the FCC.
4. From time to time, the Telephone Company may make changes in its
facilities, equipment, or operations that could affect the operation of this
equipment. If this occurs, the Telephone Company is required to provide
you with advance notice so you can make the modifications necessary to
maintain uninterrupted service.

3
MULTIPORT CSU/DSU
CERTIFICATION NOTICE FOR
EQUIPMENT USED IN CANADA
The Canadian Department of Communications label identifies certified
equipment. This certification means that the equipment meets certain
telecommunications-network protective, operation, and safety
requirements. The Department 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. In some cases, the company’s inside wiring associated with a
single-line individual service may be extended by means of a certified
connector assembly (extension cord). 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—in this case, your 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.
The LOAD NUMBER (LN) assigned to each terminal device denotes the
percentage of the total load to be connected to a telephone loop which is
used by the device, to prevent overloading. The termination on a loop may
consist of any combination of devices, subject only to the requirement that
the total of the load numbers of all the devices does not exceed 100.

4
MULTIPORT CSU/DSU
NORMAS OFICIALES MEXICANAS (NOM)
ELECTRICAL SAFETY STATEMENT
INSTRUCCIONES DE SEGURIDAD
1. Todas las instrucciones de seguridad y operación deberán ser leídas antes de
que el aparato eléctrico sea operado.
2. Las instrucciones de seguridad y operación deberán ser guardadas para
referencia futura.
3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de
operación deben ser respetadas.
4. Todas las instrucciones de operación y uso deben ser seguidas.
5. El aparato eléctrico no deberá ser usado cerca del agua—por ejemplo, cerca
de la tina de baño, lavabo, sótano mojado o cerca de una alberca, etc..
6. El aparato eléctrico debe ser usado únicamente con carritos o pedestales que
sean recomendados por el fabricante.
7. El aparato eléctrico debe ser montado a la pared o al techo sólo como sea
recomendado por el fabricante.
8. Servicio—El usuario no debe intentar dar servicio al equipo eléctrico más allá
a lo descrito en las instrucciones de operación. Todo otro servicio deberá ser
referido a personal de servicio calificado.
9. El aparato eléctrico debe ser situado de tal manera que su posición no
interfiera su uso. La colocación del aparato eléctrico sobre una cama, sofá,
alfombra o superficie similar puede bloquea la ventilación, no se debe colocar
en libreros o gabinetes que impidan el flujo de aire por los orificios de
ventilación.
10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de calor
como radiadores, registros de calor, estufas u otros aparatos (incluyendo
amplificadores) que producen calor.
11. El aparato eléctrico deberá ser connectado a una fuente de poder sólo del
tipo descrito en el instructivo de operación, o como se indique en el aparato.

5
MULTIPORT CSU/DSU
12. Precaución debe ser tomada de tal manera que la tierra fisica y la polarización
del equipo no sea eliminada.
13. Los cables de la fuente de poder deben ser guiados de tal manera que no
sean pisados ni pellizcados por objetos colocados sobre o contra ellos,
poniendo particular atención a los contactos y receptáculos donde salen del
aparato.
14. El equipo eléctrico debe ser limpiado únicamente de acuerdo a las
recomendaciones del fabricante.
15. En caso de existir, una antena externa deberá ser localizada lejos de las lineas
de energia.
16. El cable de corriente deberá ser desconectado del cuando el equipo no sea
usado por un largo periodo de tiempo.
17. Cuidado debe ser tomado de tal manera que objectos liquidos no sean
derramados sobre la cubierta u orificios de ventilación.
18. Servicio por personal calificado deberá ser provisto cuando:
A: El cable de poder o el contacto ha sido dañado; u
B: Objectos han caído o líquido ha sido derramado dentro del aparato; o
C: El aparato ha sido expuesto a la lluvia; o
D: El aparato parece no operar normalmente o muestra un cambio en su
desempeño; o
E: El aparato ha sido tirado o su cubierta ha sido dañada.

6
MULTIPORT CSU/DSU
TRADEMARKS
The trademarks mentioned in this manual are the sole property of their owners.

7
MULTIPORT CSU/DSU
Contents
1. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.2 Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3. Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1 Configuring the Hardware DIP Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.1 DIP Switch Set S1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1.2 DIP Switch Set S2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1.3 DIP Switch Set S3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2 Configuring the Software Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.2.1 Introduction to the Main Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.2.2 Configuring the Multiport CSU/DSU . . . . . . . . . . . . . . . . . . . . . . . . . 23
4. Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.1 Connecting the Serial Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.1.1 Changing the Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.1.2 Connecting a DTE Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.1.3 Connecting a DCE Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.1.4 Configuring the X.21 Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.2 Connecting the Twisted Pair Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.3 Connecting Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
5. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
5.1 Power-On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
5.2 LED Status Monitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
5.3 Loop (V.54 and Telco) Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
5.3.1 Operating Local Analog Loopback (LAL) . . . . . . . . . . . . . . . . . . . . . . 34
5.3.2 Operating Remote Digital Loopback (RDL) . . . . . . . . . . . . . . . . . . . . 35
5.3.3 Telco Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
5.4 Bit Error Rate (V.52) Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Appendix A: Interface Pin Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Appendix B: Control Port Pin Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Appendix C: Quick Reference for DIP Switch Settings . . . . . . . . . . . . . . . . . . . . . 42

8
MULTIPORT CSU/DSU
1. Specifications
Compatibility—AT&T 62310
DDS Line Interface—Externally accessible RJ-48 female
Transmission Format—Synchronous or asynchronous
Transmission Line—Two unconditioned twisted pair
Clock Options—Internal, external, receive loopback, and campus
Interfaces—Modules: RS-232 (DB25 female), RS-422/530 (DB25 female), V.35
(M/34 female), X.21 (DB15), G.703 (RJ-45), Ethernet Bridge
Speeds—Synchronous: 2.4, 4.8, 9.6, 19.2, 56, and 64 kbps; Asynchronous: 2.4,
4.8, 9.6, 19.2, 38.4, and 57.6 kbps
Diagnostics—V.54-compliant local and remote loopbacks; V.52-compliant 511
and 2047 BER tests
Indicators—Front-panel LEDs: DDS line rates (2.4, 4.8, 9.6, 19.2, 38.4, and 57.6
kbps), Power, TD, RD, RTS, CTS, DCD, DSR, DTR, No Signal, Test Mode,
Error Indication
Distance— -49 dBm receiver sensitivity or better
RTS/CTS Delay—0 ms/50 ms
Front-Panel Switches—Loopback indication and Bit Error Rate Test
Temperature Range—32 to 122 °F (0 to 50 °C)
Altitude—Up to 15,000 feet (4572 m)
Humidity—5 to 95% noncondensing
Surge Protection—600 W Power Dissipation
Lightning Protection—Gas Tube
Isolation—1500 V via isolation transformers
Approvals—FCC Part 68, FCC Part 15, Class A, CE marked per EMC Directive
89/336/EEC and Low Voltage Directive 73/23/EEC, UL and cUL safety
approvals

9
MULTIPORT CSU/DSU
Power—Universal Input (UI): 100 to 253 VAC; Input: DC: 18 VDC to 72 VDC,
48 V nominal
Size—1.6"H x 7.3"W x 6.6"D (4.1 x 18.5 x 16.8 cm)
Weight—2 lb. (0.9 kg)

10
MULTIPORT CSU/DSU
2. Introduction
2.1 Description
The Multiport CSU/DSU (part number MT210A) provides Digital Data Service
(DDS) access. It connects to your network devices via your choice of
interchangeable interface modules. With sync operation at up to 64 kbps or async
at up to 57.6 kbps, the CSU/DSU is versatile, reliable, and hassle-free.
The CSU/DSU complies with AT&T 62310 and supports DDS, Clear Channel
64, and other digital services available from major service providers. Configure the
CSU/DSU for the application using externally accessible hardware DIP switches or
via menu-driven software switches. After installation, easy-to-read front-panel LED
indicators monitor data and control signals. The CSU/DSU also offers convenient
V.52 BER and V.54-compliant loop diagnostics.
Replaceable modules come with a variety of interfaces. Select from the
following:
• RS-232 (DB25 female) (part number ME481C-232)
• RS-422/530 (DB25 female) (part number ME481C-422)
• V.35 (M/34 female) (part number ME481C-35)
• X.21 (DB15) (part number ME481C-X21)
• G.703 (RJ-45) (part number ME481C-G703)
• Ethernet Bridge (part number ME530A)
The CSU/DSU connects to the line side via an RJ-48 female jack. It receives
power from an included 100–253 VAC universal power supply.
For how to connect the modules to a DTE or DCE device, see Sections 4.1.2 and
4.1.3. For more information about a specific interface module, refer to the manual
supplied with that module.
2.2 Features
• Operates over 4-wire dedicated digital lines.
• Synchronous Data Rates: 2.4, 4.8, 9.6, 19.2, 56, and 64 kbps

11
MULTIPORT CSU/DSU
• Asynchronous Data Rates: 2.4, 4.8, 9.6, 19.2, 38.4, and 57.6 kbps
• Field-replaceable DTE-DCE interface modules: V.24/RS-232, V.35,
RS-422/530, G.703, X.21, and Ethernet Bridge
• V.52 BER and V.54-compliant loop diagnostics
• 511 and 2047 Bit Error Rate Tests
• 24 easy-to-read LED indicators to monitor data signals
• Internal, external, received loopback, and campus clock modes
• AT&T 62310 compliant
• Can be used as a high-speed modem for private twisted-pair lines
• Made in the USA

12
MULTIPORT CSU/DSU
3. Configuration
You can configure the Multiport CSU/DSU via hardware switches or a software
control port. This section describes all possible configurations.
3.1 Configuring the Hardware DIP Switches
The CSU/DSU has 24 DIP switches that you can configure for a wide variety of
applications. The 24 switches are grouped into three eight-switch sets. You can
access them externally from the underside of the CSU/DSU (see Figure 3-1).
Figure 3-1. Underside of the CSU/DSU, Showing the Location of the DIP
Switches.
The three sets of DIP switches on the underside of the CSU/DSU will be
referred to as S1, S2, and S3. Figure 3-2 shows the orientation of all DIP switches
with respect to “ON” and “OFF” positions.
Figure 3-2. Close-up of Configuration Switches (all three sets are identical
in appearance).
ON
12345678
ON
OFF
S1
S2
S3
OFF ON
Front
Back

13
MULTIPORT CSU/DSU
3.1.1 DIP S
WITCH S ET S1
You can use the DIP switches on set S1 to configure the DTE rate, RTS/CTS delay,
anti-stream timer, data format, character length, and Extended Signalling Rate
(ESR). Default settings are shown in Table 3-1. All settings are shown in Table
C-1. Detailed descriptions for each switch in the set appear below and on pages
13–14.
Table 3-1. S1 Summary Table.
Position Function Factory Default
S1-1 DTE Rate Off DTE Rate equals
S1-2 DTE Rate Off Line Rate
S1-3 DTE Rate Off
S1-4 RTS/CTS Delay Off Normal
S1-5 Anti-Stream Timer Off Off
S1-6 Data Format Off Synchronous
S1-7 Character Length Off 10 Bits
S1-8 Extended Signal Rate Off Off
Switches S1-1, S1-2, and S1-3: Data Rate
Use switches S1-1, S1-2, and S1-3 to configure the DTE rate of the CSU/DSU. This
rate represents the synchronous or asynchronous rate at which the DTE must
connect to the CSU/DSU’s interface module.
Table 3-2. Settings for Switches S1-1, S1-2, and S1-3.
S1-1 S1-2 S1-3 DTE Rate
On On On 2.4 kbps
On On Off 4.8 kbps
On Off On 9.6 kbps
Off On Off 19.2 kbps
On On Off 38.4 kbps
Off On On DTE Rate=Line Rate*
*NOTE
To achieve 56 kbps or 64 kbps, use this switch combination.
}

14
MULTIPORT CSU/DSU
Switch S1-4: RTS/CTS Delay
The RTS/CTS delay is the amount of time it takes for CTS to change logic state
following an RTS transition. Use Switch S1-4 to select the RTS/CTS delay
(measured in msec).
Table 3-3. Settings for Switch S1-4.
RTS/CTS Delay in msec. at Various Line Rates
S1-4 Delay 56 19.2 9.6 4.8 2.4
Off Normal 0.3 0.9 1.9 3.8 7.5
On Extended 1.3 3.8 7.5 15 30
Switch S1-5: Anti-Stream Timer
The anti-stream timer protects multidrop networks from a drop that is
continuously transmitting. If the DTE keeps RTS raised for more than the time
value in seconds, the timer forces RTS off internally. This allows the rest of the
multidrop network to resume operation. The CSU/DSU remains in the forced-off
condition until the terminal drops RTS. Use Switch S1-5 to enable the timer.
Table 3-4. Settings for Switch S1-5.
Timer Value in Sec. at Various Line Rates
S1-5 Timer 56 19.2 9.6 4.8 2.4
On Disabled not applicable
Off Enabled 2481530
Switch S1-6: Data Format
Use Switch S1-6 to configure the CSU/DSU for synchronous or asychronous
connection to the DTE.
Table 3-5. Settings for Switch S1-6.
S1-6 Setting
Off Synchronous
On Asynchronous

15
MULTIPORT CSU/DSU
Switch S1-7: Asynchronous Character Length
Set Switch S1-7 to configure the total number of asynchronous bits per
asynchronous character (when Switch S1-6 is set to “On”).
Table 3-6. Settings for Switch S1-7.
S1-7 Setting
Off 10 bits
On 11 bits
NOTE
The total number of bits in an asynchronous character is determined by
the sum of all start bits, data bits, stop bits, and parity bits. For
instance:
1 start bit + 8 data bits + 1 stop bit + 0 parity bits = 10 bits
Switch S1-8: Extended Signaling Rate
Use S1-8 to configure the frequency tolerance the CSU/DSU looks for in
asynchronous data rates (the actual variance from a given frequency level the
CSU/DSU will tolerate).
Table 3-7. Settings for Switch S1-8.
S1-8 Setting
Off -2.5% to +1%
On -2.5% to +2.3%
3.1.2 DIP S WITCH S ET S2
You can use the DIP switches on set S2 to configure the line rate, clock mode, force
RTS, and DSR status during local loop. Default settings are shown in Table 3-8. All
settings are shown in Table C-2. Detailed descriptions for each switch in the set
appear on pages 15–17.

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MULTIPORT CSU/DSU
Table 3-8. S2 Summary Table.
Position Function Factory Default
S2-1 Line Rate Off
S2-2 Line Rate On 56 kbps
S2-3 Line Rate On
S2-4 Clock Mode Off
S2-5 Clock Mode Off
S2-6 Force RTS Signal Off Disabled
S2-7 DSR During Local Loop Off Off
S2-8 Circuit Assurance Off Disabled
Switches S2-1, S2-2, and S2-3: Line Rate
Use Switches S2-1, S2-2, and S2-3 to configure the signaling rate on the line (RJ-48
female port). The setting should match the speed of your digital service.
Table 3-9. Settings for Switches S2-1, S2-2, and S2-3.
S2-1 S2-2 S2-3 Line Rate
On On On 2.4 kbps
On On Off 4.8 kbps
On Off On 9.6 kbps
On Off Off 19.2 kbps
Off On On 57.6 kbps
Off On Off 64 kbps
Off Off Off Forces configuration to default
to hardware control.
}
}Network

17
MULTIPORT CSU/DSU
Switches S2-4 and S2-5: Clock Mode
Use Switches S2-4 and S2-5 to set the source of the CSU/DSU’s transmit clock.
Table 3-10. Settings for Switches S2-4 and S2-5.
S2-4 S2-5 Clock Mode Description
On Off External (DTE) Transmit clock derived from terminal
interface.
Off Off Network (Looped) Transmit clock derived from the
received line signal; use this mode for
dedicated DDS operation.
On On Internal (Master) Transmit clock derived internally.
Off On Campus Clock Transmit clock derived from the
received line signal. Allows remote
device (in campus clock mode) to
initiate V.54 loopback. For use only in
campus short-haul configuration.
(NOTE: Local device must be set in
internal clock mode.)
NOTE
For X.21 or async campus short-haul modem applications, configure
one Multiport CSU/DSU for internal clock mode and the other CSU/DSU
for receive recover clock mode.
Switch S2-6: Force RTS
Use S2-6 to force the transmitter On, thereby ignoring the DTE’s RTS signal. In
the Off position, RTS controls the transmitter by forcing it to send either the DTE
data or an idle pattern.
Table 3-11. Settings for Switch S2-6.
S2-6 RTS Description
On Forced On Transmitter is always ON
Off Follows DTE signal The RTS input controls the transmitter

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MULTIPORT CSU/DSU
Switch S2-7: Data Set Ready During LOCAL Loopback Test
Use Switch S2-7 to control the behavior of the DSR signal at the DTE interface
during the local loopback test.
Table 3-12. Settings for Switch S2-7.
S2-7 Setting
On DSR is on during local line loop
Off DSR is off during local line loop
Switch S2-8: Circuit Assurance
On dedicated circuits, you can configure the transmitter and the CTS output to go
on only when a working communication circuit is established. If Circuit Assurance
is used, enable it on only one end of the communication link. Use Switch S2-8 to
configure circuit assurance.
Table 3-13. Settings for Switch S2-8.
S2-8 Circuit Assurance Description
On Enabled CTS will go low and the transmitter will be held
off if the receiver is in the “No Signal” state or CD
is low.
Off Disabled The transmitter and CTS will operate without
regard to the receiver state.

19
MULTIPORT CSU/DSU
3.1.3 DIP S
WITCH S ET S3
The configuration switches on S3 set the BER Test pattern, response to remote
loop, front-panel switch activation, DTE loop request, and control-port speed. The
default settings are shown in Table 3-14. All settings appear in Table C-3. Detailed
descriptions for each switch in the set appear on pages 18–20.
Table 3-14. S3 Summary Table.
Position Function Factory Default
S3-1 Test Pattern Off 511
S3-2 RDL Response Off Enabled
S3-3 Front Panel Switches Off Enabled
S3-4 DTE Loop Request On Disabled
S3-5 Reserved for future use
S3-6 Reserved for future use
S3-7 Control Port Speed Off
S3-8 Control Port Speed Off
Switch S3-1: Test Pattern
Use Switch S3-1 to set the V.52-compliant pattern used to test the CSU/DSU. The
two test options are the 511 and the 2047 BER patterns (for descriptions of these
patterns, see Section 5.4).
Table 3-15. Settings for Switch S3-1.
S3-1 Setting
Off 511 Pattern
On 2047 Pattern
}19.2 kbps