Black Box MD640A-ST-R2 User manual

CUSTOMER
SUPPORT
INFORMATION
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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]
FEBRUARY 1996
MD640A-ST-R2
MD640A-SMA-R2
MD640AE-ST-R2
MD640AE-SMA-R2
MultiMode FOMs -ST and -SMA
POWER
Test
Modes
Remote
Normal
Local
TD RD CDRTS
MultiMode FOM

Contents
Chapter Page
1. Specifications ............................................................................................. 1
2. Introduction ............................................................................................... 3
2.1 Features ............................................................................................... 3
2.2 Description .......................................................................................... 4
3. Configuration ............................................................................................. 5
4. Installation .................................................................................................. 8
4.1 Single-Fiber Connection ..................................................................... 8
4.2 RS-232 Connection ............................................................................. 9
5. Operation ................................................................................................. 10
5.1 LED Indicators .................................................................................. 10
5.2 Power-Up ........................................................................................... 11
5.3 Loopback-Test Modes ....................................................................... 11
5.4 Power-Down ....................................................................................... 12
6. Troubleshooting ...................................................................................... 13
6.1 Calling Black Box .............................................................................. 13
6.2 Shipping and Packaging ................................................................... 13
Appendix: RS-232 Pinout .............................................................................. 14

MULTIMODE FOMS -ST AND -SMA
TRADEMARKS USED IN THIS MANUAL
ST is a registered trademark of AT&T.
Any other trademarks mentioned in this manual are acknowledged to be the property
of the trademark owners.

1
CHAPTER 1: Specifications
Cable Required — (1) Multimode fiberoptic cable, 62.5-µm core
Interface — EIA RS-232/CCITT V.24, DCE
Protocols — Asynchronous or synchronous
Clock — Internal or external from attached RS-232 device
Flow Control — Transparent hardware (RTS/CTS and DTR/DSR
passed through from DTE) or local hardware or
software (RTS/CTS or X-ON/X-OFF), user-
selectable
Operating Mode — Point-to-point
Speed — Asynchronous: Up to 38.4 Kbps;
Synchronous: 2.4, 9.6, 19.2, 38.4, 56, 64, 192, or
256 Kbps
Maximum
Distance — 2.5 km (1.5 mi.) at all data rates,
5 km (3.1 mi.) at data rates of 64 Kbps or below
Modulation — 3B4B
Wavelength — 880 nm
Attenuation — 14 dB
LED-Responsivity
Minimum — 0.12 amps per watt
User Controls — (2) External:
(1) Front-mounted rocker switch: Test;
(1) Bottom-mounted 8-position DIP switch:
Async/sync operation, data rates, clock source,
flow control
1. Specifications

2
MULTIMODE FOMS -ST AND -SMA
Indicators — (6) Front-mounted LEDs: TD, RD, RTS, CTS, Power,
Test
Diagnostics — Local and remote loopback
Connectors — (3) Rear-mounted:
(1) DB25 female;
(1) Barrel-type power jack;
Units with “-ST” suffix: (1) ST female;
Units with “-SMA” suffix: (1) SMA female
Power — For 120-VAC, 60-Hz operation:
From wallmount power supply:
Input: 115 VAC, 60 Hz, 100 mA;
Output: 10 VAC, 700 mA;
For 240-VAC, 50-Hz operation:
From desktop power supply:
Input: 230 VAC, 50 Hz, 100 mA;
Output: 10 VAC, 700 mA
MTBF — 125,000 hrs.
Maximum
Altitude — 10,000 ft. (3048 m)
Temperature — 32 to 140˚ F (0 to 60˚ C)
Humidity — Up to 95% noncondensing
Size — 1.5"H x 4.1"W x 5"D (3.9 x 10.5 x 12.7 cm)
Weight — 5 lb. (2.3 kg)

3
CHAPTER 2: Introduction
MultiMode FOMs are fiberoptic short-range modems with a special money-
saving edge. Many other fiberoptic modems can’t transmit and receive data
through the same port, so they use cables with two fibers. MultiMode FOMs
communicate with each other over a much less expensive single-fiber cable,
across distances of as much as 5 km (3.1 miles).
2.1 Features
• Synchronous or asynchronous operation
• Communicates point-to-point over a single optical fiber
• Local and remote test modes
• Asynchronous data rates up to 38.4 Kbps
• Synchronous data rates up to 256 Kbps
• Distances up to 2.5 kilometers (1.5 miles) at any speed
• Distances up to 5 kilometers (3.1 miles) at speeds of 64 Kbps or less
• Internal or external clocking
• Support for transparent hardware, or local hardware, or local software
flow control
• Available with ST®or SMA connectors
• Tri-state front-panel LED indicators
2. Introduction

4
MULTIMODE FOMS -ST AND -SMA
2.2 Description
The MultiMode FOM is a fiberoptic short-range modem for point-to-point
RS-232 communication over a single 62.5-µm fiber, such as one of those
bundled into our bulk multifiber cables EFN1004 and EFN1006. The FOM
supports synchronous data rates up to 256 Kbps, and asynchronous data rates
up to 38.4 Kbps. It can also support transparent hardware flow control or
local flow control; in the local setting, it automatically adapts to either
hardware or software flow control. Synchronous timing can be set for
internal or external (from attached RS-232 device) clock.
The MultiMode FOM features extended-data-rate circuitry that allows for
single-fiber distances between 1.5 and 3.1 miles (2.5 and 5 km). Depending
on which model you have, you can connect optical cable with ST or SMA
connectors to the FOM. The MultiMode FOM encodes your data signals
using 3B4B modulation, then converts them to an 880-nm optical signal.
The MultiMode FOM features two test modes: local and remote loopback.
You can activate either of these tests with the FOM’s front-panel toggle switch.
The local loopback test is used to evaluate the DTE-to-modem connection.
The remote loopback test is used to evaluate the condition of the connection
between the modems.

5
CHAPTER 3: Configuration
With the MultiMode FOM’s external DIP switch, you can configure the unit
for many different combinations of data rates and clocking methods for
synchronous or asynchronous applications. (Since the FOM has no internal
jumpers or other internal controls, you don’t have to open the unit’s case to
configure the unit.) Figures 3-1 and 3-2 below and Table 3-1 on the next page
show the location of the switch and the switch positions’ identities, settings,
and functions.
Figure 3-2. Closeup of the DIP switch positions showing
ON/OFF settings and position numbers.
1
ON
2345678
ON
OFF
Figure 3-1. The location of the DIP
switch on the underside of the unit.
1
ON
2345678
REAR
FRONT
3. Configuration

6
MULTIMODE FOMS -ST AND -SMA
This section provides detailed information about the function of each
DIP switch position, and lists all possible settings. Use this section as a
configuration guide for applications where the FOM’s default settings
would not provide correct results. (Position 1 is reserved for future use.)
Positions 2 though 5: Data Rate (Sync. Mode)
Switches 2 through 5 determine two configuration parameters: synchronous
or asynchronous data rate and the mode of synchronization (Sync. Mode)
between two FOMs. Here’s how the packet-spacing option works: The “2X”
setting doubles the space between data packets compared to the “1X” setting,
so that each packet is more easily distinguishable from those before and after
it. This offsets some of the effects of signal degradation over distance, and
allows communication over as much as 5 km (3.1 miles) as opposed to the
“1X” setting’s limit of 2.5 km (1.5 miles). Table 3-2 at the top of the next
page shows every possible setting for these four switch positions.
Position 6: Reset
You can use position 6 to reset the MultiMode FOM without powering down
the unit. Move position 6 to ON to put the FOM in “reset conditon,” then
move position 6 back to OFF (the default setting) to put the FOM back in
“operating condition” (resume normal operation). Don’t leave position 6
ON: the FOM will not work properly unless this switch position is OFF.
Position Function Factory Default
1 RESERVED OFF
2 Data Rate (Sync Mode) ON
3 Data Rate (Sync Mode) OFF
4 Data Rate (Sync Mode) OFF
5 Data Rate (Sync Mode) ON
6 Reset OFF Operating Mode
7 Handshaking ON Control Signal Mode
8 Clocking Method OFF Internal Clock
0 to 19.2
Async (2X)
}
Table 3-1. Summary of Switch Settings, Showing Factory Defaults

7
CHAPTER 3: Configuration
Table 3-2. Possible Settings of DIP Switch Positions 2 Through 5
Pos. 2 Pos. 3 Pos. 4 Pos. 5 Data Rate (Sync. Mode)
ON OFF OFF ON Async 0 to 19.2 Kbps (2X)
ON OFF OFF OFF Async 0 to 38.4 Kbps (1X)
ON ON ON OFF Sync at 2.4 Kbps (1X)
OFF ON ON OFF Sync at 9.6 Kbps (1X)
OFF ON ON ON Sync at 9.6 Kbps (2X)
ON ON OFF OFF Sync at 19.2 Kbps (1X)
ON ON OFF ON Sync at 19.2 Kbps (2X)
OFF ON OFF OFF Sync at 38.4 Kbps (1X)
OFF ON OFF ON Sync at 38.4 Kbps (2X)
ON OFF ON OFF Sync at 48 Kbps (1X)
ON OFF ON ON Sync at 48 Kbps (2X)
OFF OFF ON OFF Sync at 56 Kbps (1X)
OFF OFF OFF OFF Sync at 64 Kbps (1X)
OFF OFF OFF ON Sync at 64 Kbps (2X)
OFF OFF ON ON Sync at 192 Kbps (1X)
ON ON ON ON Sync at 256 Kbps (1X)
Position 7: Handshake Mode
Use position 7 to set the type of flow control. (This switch position must be
moved to the same setting on both FOMs.) If position 7 is set to ON (the
default setting), the Multimode FOMs perform transparent hardware flow
control by passing the RTS/CTS and DTR/DSR signal pairs from the
attached DTEs across the modem link. In this setting, when one FOM drops
the RS-232 “RTS” signal, the other FOM drops the “CTS” signal, and when
one FOM drops the “DTR” signal, the other drops the “DSR” signal.
If position 7 is set to OFF (the “standard modem” setting), each FOM
independently performs flow control between itself and the local DTE,
automatically adapting to either hardware (RTS/CTS) or software
(X-ON/ X-OFF) flow control.
Position 8: Clock Source
Use position 8 to set the clock source. The MultiMode FOM works from an
internal clock if position 8 is set to OFF (the default setting) and provides this
clock signal on RS-232 Pin 15. The FOM receives an external clock from the
attached RS-232 device on RS-232 Pin 24 if position 8 is set to ON.