Black Box ME605A-FST User manual

APRIL 1998
ME605A-FST
ME605A-MST
Async Fiber Optic Mini Modem
CUSTOMER SUPPORT INFORMATION
Order toll-free in the U.S. 24 hours, 7 A.M. Monday to midnight Friday: 877-877-BBOX
FREE technical support, 24 hours a day, 7 days a week: Call 724-746-5500 or fax [phone]
Mail order: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: [email protected]
DATA
TX RX

1
TRADEMARKS
TRADEMARKS
The trademarks mentioned in this manual are the sole property
of their owners.

2
ASYNC FIBER OPTIC MINI MODEM
CONTENTS
1. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Application. . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3
CHAPTER 1: Specifications
1. Specifications
Data Rate — Up to 19.2 Kbps
Pulse Width Distortion — Less than 25%
Transmission Line — Duplex optical cable
Transmission Mode — Asynchronous, full-
or half-duplex
Transmission Controls — Carrier constantly on
or controlled by RTS
Optical Output Levels — -28 dBm into 100/140 fiber;
-32 dBm into 62.5/125 fiber;
-36 dBm into 50/125 fiber
Receiver Sensitivity — -45 dBm
Operating Wavelength — 850 nm
Operating Range — Maximum range is 2 miles (3 km)
of continuous fiber with the following fibers: 100/140
fiber with attenuation of 4 dB/km; 62.5/125 fiber with
attenuation of 3.5 dB/km; 50/125 fiber with
attenuation of 3 dB/km

4
ASYNC FIBER OPTIC MINI MODEM
Indicators — (1) Power LED
Terminal Interface — (1) ITU V.24/EIA RS-232C
integral DB25 male or female connector
Fiberoptic Interface — (2) ST connectors
Temperature — 32 to 122°F (0 to 50°C)
Humidity — Up to 90%, noncondensing
Power — None required; uses ultra-low power
from the data and control signals
Size — 0.7”H x 2.1”W x 3.1”D (1.8 x 5.3 x 7.8 cm)
Weight — 1.3 oz. (36 g)

5
CHAPTER 2: Description
2. Description
2.1 General
The Async Fiber Optic Mini Modem is used for local
data distribution, connecting full- or half-duplex async
computers and terminals. A pair of modems ensures
integrity of data transmission over fiberoptic cable at
distances up to 2 miles (about 3 km).
The Modem features a switch-selectable DCE/DTE
option. This allows operation as DTE, for connection to
another DCE such as a multiplexor port, eliminating the
need for a cross cable. The carrier can be strapped for
either continuous operation, or for switched operation,
controlled by the RTS signal, for transfer of a control
signal end-to-end.
Innovative circuitry allows the Modem to operate
without connection to the mains power supply, by
using ultra-low power from the data and control signals.
The Modem operates even if only transmit data is
connected—no control signals or any other source
of power are required.

6
ASYNC FIBER OPTIC MINI MODEM
The Modem comes in a durable plastic case.
The Modem incorporates all the advantages
of a fiberoptic system, providing:
• Lower attenuation than with copper wire.
NOTE
Attenuation is not related to frequency.
• EMI/RFI immunity, saving the cost of expensive
and heavy shielding, and complex error checking
routines.
• Almost absolute security and reduction in the
cost of data encryption; eavesdropping is virtually
impossible since negligible power is radiated from
the fiber.
• Safety and electrical isolation: no spark hazard
and no ground-loop noise problems.

7
CHAPTER 2: Description
2.2 Features
• Asynchronous transmission up to 19.2 Kbps.
• Transmission range up to 2 miles
(about 3 km), regardless of data rate.
• Full- or half-duplex operation.
• Transfers one control signal end-to-end.
• DCE-DTE switch.
• No external power required.
• Plugs directly into V.24/RS-232C terminal
connector.
• Compact, lightweight, and easy to install.

8
ASYNC FIBER OPTIC MINI MODEM
2.3 Application
A pair of Async Fiber Optic Mini Modems ensures
secure data transmission over fiberoptic cable at
distances up to 2 miles (about 3 km).
Figure 2-1. Typical application of the modem.
ME605A ME605A
Async
Computer
Async
Terminal
Fiberoptic Cable
2 miles (3 km)

9
CHAPTER 3: Installation
3. Installation
Installation of the Modem is simple. Just follow these
instructions:
1. To access the switches, insert a slim screwdriver
under the nameplate and ease the nameplate off.
2. Strap the modem according to the strapping
diagram (Figure 3-1) and the strap selection
table (Table 3-1). Explanations of the switches
are also given on the printed circuit board.
Figure 3-1. Strapping diagram.
DATA
TX RX
DTE
DCE
SW1
SW2
CARR
DLY
CL ON
15ms 2ms

10
ASYNC FIBER OPTIC MINI MODEM
Table 3-1. Strap/Switch Selection.
Strap Identity Function Position Factory Setting
CARR Selects Carrier On (ON) ON
constantly ON controlled (CL)
controlled by RTS
DLY Selects RTS/CTS 2 msec 2 msec
delay 15 msec
DCE/DTE Selects DCE or DTE DTE
Switch DCE DCE
3. The Modem is factory-set for DCE. For DTE
operation, move the switch to the DTE position
(see Figure 3-2).
Figure 3-2. DTE/DCE Switch Operation.
TD
RD
RTS
CTS
DSR
DCD
DTR
2
3
4
5
6
8
20
DI
DO
RTS
+V
CD
N.C.
DCE Position
D
300 ohm
TD
RD
RTS
CTS
DSR
DCD
DTR
2
3
4
5
6
8
20
DI
DO
CD
+V
DTE Position
300 ohm
N.C.
N.C.
N.C.

11
CHAPTER 3: Installation
4. To close the unit, snap the nameplate back into
place. Plug the modem directly into the DB25
connector of the terminal/computer port and
tighten the screws on each side of the modem
connector.
5. Remove the plastic dust caps from the fiberoptic
connectors and connect the cable to the unit.
Observe the following directions:
• TX on the local modem should be
connected to RX on the remote modem.
• RX on the local modem should be
connected to TX on the remote modem.
6. The Modem is now ready for operation. The red
Data LED lights when the modem is receiving
power.

NOTES

1000 Park Drive • Lawrence, PA 15055-1018 • 724-746-5500 • Fax [phone]
© Copyright 1998. Black Box Corporation. All rights reserved.