Black Box V.35 256/ST Series User manual

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SUPPORT
INFORMATION
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APRIL 1996
ME525A-ST
ME525AE-ST
ME525A-SMA
ME525AE-SMA
V.35 Single Fiber Driver 256/ST
V.35 Single Fiber Driver 256/SMA
POWER TD RDRTS CD
Test
Modes
Remote
Normal
Local
V.35 Single Fiber Driver

2
V.35 SINGLE FIBER DRIVERS
TRADEMARKS USED IN THIS MANUAL
ST is a registered trademark of AT&T.
UL is a registered trademark of Underwriters Laboratories Incorporated.
All applied-for and registered trademarks are the property of their respective owners.

3
FCC STATEMENT
FEDERAL COMMUNICATIONS COMMISSION
AND
INDUSTRY CANADA
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 Industry Canada.
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites
applicables aux appareils numériques de classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par Industrie Canada.

4
V.35 SINGLE FIBER DRIVERS
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.

5
NOM STATEMENT
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.
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
V.35 SINGLE FIBER DRIVERS
Contents
Chapter Page
1. Specifications....................................................................................................7
2. Introduction .....................................................................................................8
3. Configuration ...................................................................................................9
4. Installation......................................................................................................13
4.1 Single-Fiber Connection .........................................................................13
4.2 V.35 Connection......................................................................................14
5. Operation .......................................................................................................15
5.1 LED Status Monitors ...............................................................................15
5.2 Power-up/Synchronization.....................................................................16
5.3 Loopback Test Modes .............................................................................17
5.3.1 Local Loopback...........................................................................17
5.3.2 Remote Loopback .......................................................................17
5.4 Power-down..............................................................................................18
Appendix A: Troubleshooting ..........................................................................19
Appendix B: Interface Pin Assignment.............................................................21

7
CHAPTER 1: Specifications
Protocol — Synchronous
Range — 1.5 miles (2.4 km) at data rates above
64 Kbps and 3 miles (4.8 km) at data
rates below 64 Kbps
Data Rates — 2.4, 9.6, 14.4, 19.2, 28.8, 38.4, 48, 56, 64,
128, 144, 192, and 256 Kbps
Interface — CCITT V.35 (M/34 female)
Transmit Mode — Single 62.5- or 50-µcore, multimode
fiber cable
Clocking — Internal, external, or received recovered
Handshaking — Software (X-ON/X-OFF) or hardware
(RTS/CTS), both modes available at all
times
Application — Point to point
Typical Link Budget — 8 dB with a 50-µcable; 12 dB with a 62.5-
µcable
Responsivity Minimum — 0.12 A/w
Indicators — (6) LEDs: TD, RD, RTS, CTS, power, test
Diagnostics — Local and remote loopback
Connectors — (1) M/34 female; (1) ST®or SMA
MTBF — 224,205 hours (about 25.5 years)
MTTR — 1 hour
Operating Temperature — 32 to 140°F (0 to 60°C)
Relative Humidity — 95%, noncondensing
Altitude Tolerance — Up to 10,000 feet (3048 m)
Compliance — UL®, CSA, CE, TUV
Power Supply — Wallmount, 7.5 VDC, 115 VAC, 60 Hz
Size — 1.5"H x 4.1"W x 5"D (3.8 x 10.4 x
12.7 cm)
Weight — 1 lb. (0.5 kg)
1. Specifications

8
V.35 SINGLE FIBER DRIVERS
The V.35 Single Fiber Drivers are high-speed fiber modems that support full-
duplex, point-to-point V.35 communication over a single multimode fiber.
Running at synchronous speeds up to 256 Kbps, the V.35 Single Fiber Drivers
automatically adapt to hardware or software flow control, and can be set for
internal, external, or received recover clocking.
Connect optical fiber to the Driver with an ST or SMA interface. The Driver’s
V.35 DTE interface is a female M/34 connector (see Appendix B for its
pinout).
The V.35 Single Fiber Driver features local and remote loopback tests, six
front-panel LEDs, and externally accessible configuration switches.
For proper operation, these Drivers must be used in pairs.
2. Introduction

9
CHAPTER 3: Configuration
The V.35 Single Fiber Driver uses an eight-switch package that can con-
figure a wide range of synchronous applications. Since all eight switches are
externally accessible (see the illustrations below), there’s no need to open
the Driver’s case for configuration.
Figure 3-1. The 8-switch package is located underneath the Driver.
Figure 3-2. A closeup of the switches. All eight
switches are shown in the “ON” position.
ON
1 2 3 4 5 6 7 8
ON
OFF
FRONT
REAR
3. Configuration

10
V.35 SINGLE FIBER DRIVERS
The eight configuration switches set data rate (distance), sync clock source,
and DTE control of the RDL and LAL test modes. The table below shows
which switches control each function, and the factory-default settings.
Table 3-1. DIP-switch default settings and functions
Switch Number Function Factory-Default Setting
S1-1 Data Rate (Distance) Off
S1-2 Data Rate (Distance) Off 64 Kbps (2X)
S1-3 Data Rate (Distance) Off
S1-4 Data Rate (Distance) On
S1-5 Clock Source On Internal
S1-6 Clock Source On
S1-7 DTE Control of RDL On Enabled
S1-8 DTE Control of LAL On Enabled

11
CHAPTER 3: Configuration
Switches S1-1 through S1-4: Data Rate (Distance)
Switches S1-1 through S1-4 are set in combination to determine synchronous
data rate and maximum distance. Maximum distance is determined by the
space between data packets in the communication stream between two V.35
Single Fiber Drivers. The “2X” setting doubles the space between data packets,
when compared with the normal “1X” setting, and therefore doubles the
maximum distance. A setting of “2X” supports communication distances up to
3 miles, and is available at certain data rates up to 64 Kbps. A setting of “1X”
supports communication at the normal distance of 1.5 miles.
S1-1 S1-2 S1-3 S1-4 Data Rate (Distance)
On On On Off 2.4 (1X)
Off On On On 9.6 (2X)
On Off On Off 14.4 (1X)
On Off On On 19.2 (2X)
Off Off On Off 28.8 (1X)
Off Off On On 38.4 (2X)
On On Off On 48 (2X)
Off On Off Off 56 (1X)
Off Off Off On 64 (2X)
Off On On Off 72 (1X)
Off Off Off Off 128 (1X)
On On Off Off 144 (1X)
Off On Off On 192 (1X)
On On On On 256 (1X)

12
V.35 SINGLE FIBER DRIVERS
S1-5 and S1-6: Clock Source
Switches S1-5 and S1-6 are set in combination to determine the source of the
transmit clock.
S1-5 S1-6 Setting
Off Off Received Recover Clock
On Off Internal Clock
Off On External Clock
On On Internal Clock
S1-7: DTE Control of RDL
The setting for switch S1-7 determines whether DTE control of remote digital
loopback test is enabled or disabled. If DTE control is disabled, the RDL test
can only be initiated by the front-panel switch.
If DTE control is not available, switch S1-7 should be set to off.
S1-7 Setting
On DTE control of RDL enabled
Off DTE control of RDL disabled
S1-8: DTE Control of LAL
The setting for switch S1-8 determines whether DTE control of local analog
loopback test is enabled or disabled. If DTE control is disabled, the LAL test
can only be initiated by the front-panel switch.
If DTE control is not available, switch S1-8 should be set to off.
S1-8 Setting
On DTE control of LAL enabled
Off DTE control of LAL disabled

13
CHAPTER 4: Installation
The V.35 Single Fiber Driver is easy to install. Once you’ve configured the DIP
switches (described in Chapter 3), simply connect the single fiber cable, hook
up the V.35 interface, and plug the power-supply adapter into the Driver. The
illustration below shows the interface connections on the back of the V.35
Single Fiber Driver.
Figure 4-1. The Driver’s rear panel.
4.1 Single-Fiber Connection
These short-range modems are designed to work in pairs. You will need one at each
end of the single multimode fiber cable. Depending which data-rate setting
you select, your cable may be a maximum of 1.5 or 3 miles long. The fiber
cable connects to each V.35 Single Fiber Driver using either an ST or an
SMA connector. The illustration on the next page shows a closeup of both
connectors.
4. Installation
V.35 Interface
Power Fiber

14
V.35 SINGLE FIBER DRIVERS
Figure 4-2. ST and SMA connectors.
4.2 V.35 Connection
The V.35 Single Fiber Driver is configured as a DCE. Therefore, it “wants” to
connect to DTE hardware such as a PC, host, or terminal, using a straight-
through cable. Connecting the Driver to DCE hardware, such as a modem,
multiplexor, or printer, requires a null-modem V.35 cable. Contact your
supplier for more information about constructing the appropriate null-
modem cable for your application.
Alignment pin
faces down

15
CHAPTER 5: Operation
Once you’ve configured each V.35 Single Fiber Driver and connected the
fiber and V.35 cables, you’re ready to operate the units.
5.1 LED Status Monitors
The Driver has six front-panel status LEDs that indicate the condition of the
modem and communication link. The illustration below shows the location of
each LED.
Figure 5-1. The front of the V.35 Single Fiber Driver.
• The green “Power” LED glows if power is applied to the modem.
• The green “Test Modes” LED indicates that the modem is in test mode
(local analog or remote digital).
• The “TD” and “RD” indicators blink red and green with data activity. Red
indicates a low V.35 logic level; green indicates a high V.35 logic level.
V.35 devices idle in a low state, so the LED will glow red if the connections
are correct and the V.35 device is in an idle state.
• The “RTS” and “CD” indicators are also tri-state and will glow red for a
“low” signal or green for a “high” signal. RTS lights for an incoming signal
on V.35 pin C. CD lights for an incoming signal on the line side, and the
resulting output signal on V.35 pin F.
TD RD RTS CD
Test
Modes
POWER Remote
Normal
Local
5. Operation

16
V.35 SINGLE FIBER DRIVERS
5.2 Power-up/Synchronization
Apply AC power to the V.35 Single Fiber Driver by plugging the separate AC
power adapter first into the rear-panel outlet of the Driver (refer to Figure 4-1
in Chapter 4) and then into the acceptable AC power outlet. There is no
power switch on the Driver; when the Power LED is glowing steady, the
Driver is powered up.
IMPORTANT!
Make sure the front-panel toggle switch on both V.35 Single Fiber Drivers
is set to NORMAL.
After both the local and remote Drivers are powered up, a synchronization
process must occur between the two modems before a link can be established.
Depending upon a number of factors, this synchronization process can take
as long as 60 seconds. Any time one or the Drivers loses power (in a lightning
storm, for example), the local and remote units must re-synchronize before
they can resume data transmission.
NOTE
If your application cannot tolerate a 60-second synchronization phase,
turning on the front-panel “Test Modes” switch to REMOTE and then
back to NORMAL will synchronize the units within 250 ms.
When both Drivers are powered up and passing data normally, the following
LED conditions will exist:
• PWR = green
• TD and RD = flashing red and green
• RTS and DCD = green
• TEST = off

17
CHAPTER 5: Operation
5.3 Loopback Test Modes
The V.35 Single Fiber Driver offers two loopback test modes to evaluate
the condition of the modems and the communication link. These tests are
activated from the front panel.
5.3.1 L OCAL L OOPBACK
The local loopback test checks the operation of the local V.35 Single Fiber
Driver, and is performed separately on each unit. Any data sent to the local
Driver in this test mode will be echoed back to the user device. For example,
characters typed on the keyboard of a terminal will appear on the terminal
screen.
To perform a local loopback test, follow these steps:
a) Activate local loopback by moving the front-panel toggle switch down to
“Local.” Once local loopback is activated, the Driver transmit output is
connected to its own receiver. The “test” LED should glow. (Note: Even
though the local Driver cannot communicate with the remote Driver in
this mode, the synchronized connection between the two modems remains
intact.)
b)Verify that the data terminal equipment is operating properly and can be
used for a test. If a fault is indicated, call a technician or replace the unit.
c) Perform a BERT (bit error rate) test on each unit. If the BERT test
equipment indicates no faults and the data terminal indicates a fault,
follow the manufacturer’s checkout procedures for the data terminal. Also
check the V.35 interface cable between the terminal and the V.35 Single
Fiber Driver.
5.3.2 R EMOTE L OOPBACK
The remote loopback test checks the performance of the local and remote
Drivers, and the communication link between them. (See the illustration on
the next page.) Any characters sent to the remote Driver in this test mode will
be returned to the originating device. For example, characters typed on the
keyboard of the local terminal will appear on the local terminal screen after
having been passed to the remote Driver and looped back.
To perform a remote loopback test, follow these steps:

18
V.35 SINGLE FIBER DRIVERS
a) Activate remote loopback by moving the front-panel toggle switch up to
“Remote.” The “test” LED should glow.
b)Perform a BERT (bit error rate) test on the system.
c) If the BERT test equipment indicates a fault, and the local loopback test
was successful for both V.35 Single Fiber Drivers, there may be a problem
with the fiber communication line connecting the modems. You should
test the fiber line for proper connections and continuity.
Figure 5-2. Local and remote loopback test modes.
5.4 Power-down
Turn off the V.35 Single Fiber Driver by simply unplugging the AC power
adapter from the wall. There is no power switch on the Driver.
TD
RD
TX
RX
RX
TX
RD
TD
Local Driver
in Loopback Mode Remote Driver in Normal Mode
TD
RD
TX
RX
RX
TX
RD
TD
Local Driver
in Normal Mode Remote Driver in Normal Mode

19
APPENDIX A: Troubleshooting
Symptom Problem Solution
LEDs do not light 1. Loose power connection. 1. Make sure the AC
when the AC connection is flush.
power transformer
is plugged into the 2. Outlet is defective. 2. Try a different outlet.
wall. 3. AC power cord is defective. 3. Remove the cord from the
outlet and check for continuity.
4. AC transformer is not 4. Plug it in.
plugged into the Driver.
Carrier Detect (CD) 1. If CD is low, possible 1. Check for ongoing power
LED is low synchronization loss. loss or break in fiber if CD does
not go high within 60 seconds.
or 2. Test Mode switch is in the 2. Be sure the Test Mode
Carrier Detect (CD) wrong position. switch is set to NORMAL on
LED is high, but both Drivers.
the Drivers aren’t
communicating. 3. DIP switches are set 3. Check all DIP-switch
improperly. settings, especially Reset and
Data Rate, against those listed
in Chapter 3. Make sure both
Drivers are set the same way.
4. Fiber link is connected 4. Check the ST or SMA connec-
improperly. tion on the back of both Drivers.
5. V.35 connections are faulty 5. Check V.35 cable continuity
or cables are pinned wrong. and pinning.
Appendix A: Troubleshooting

20
V.35 SINGLE FIBER DRIVERS
Symptom Problem Solution
Data passes, but 1. Incorrect DIP-switch setting. 1. Switch 7 must be in the ON
hardware flow position for hardware flow-
control doesn’t control signals to pass between
work. the Drivers; both units must be
set the same way.
Drivers work in 1. Incorrect DIP-switch setting. 1. Switch 8 (internal/external
async mode, but clock) must be set the same
not sync mode. way for both Drivers.