Black Box 202 User Manual
© 2007. All rights reserved. Black Box Corporation.
Modem 202 and Modem 202T
Reliable old favorites, manufactured to today’s exacting specifications.
•Compatible with the Bell 202T standard.
•Operate over 2- or
•Prevent data and
•Choose between ACand
An industrial application for the Modem 202.
Back in the day, Bell 202 was the
The Modem 202
Widely installed and a prerequisite for many
These modems have many uses.
You can use a Modem 202 or Modem 202T with remote terminal units (RTUs) and programmable logic controllers (PLCs) to control and monitor a large number of remote
temperature and pressure controllers in numerous industries, particularly those in which you expect to add automated devices.
Noisy lines aren’t a problem either. The Modem 202 and the Modem 202T have circuitry that prevents data errors that occur on such lines, particularly those within multidrop systems where carrier
The modems also have antistreaming features, which prevent them from remaining in Transmit Mode when they’re not actively transmitting data. Great for multipoint applications, antistreaming prevents a malfunctioning
slave modem from occupying the line indefinitely. When antistreaming is active, the Modem 202 or Modem 202T can only transmit data for up to 56 seconds. Then, they automatically turn off their transmitter and look for an
Modem 202T offers diagnostic testing features.
For testing purposes, the Modem 202T has a
2 of 3
generate a data pattern from the locally attached DTE or have the modem generate a test pattern.
You can also run line and modem tests to verify the integrity of the line between the local and remote modems. With this test, the local Modem 202T loops back received data to the transmitter and sends the data to the remote modem. These characters can be done by using a modem test pattern or by originating a data pattern from the local DTE.
Configuration is simple!
To configure the Modem 202T, just set a few DIP switches. These jumper settings control operating characteristics such
as the dynamic range of the modem receiver, the transmit level, and the call turnaround squelch (which guards against echoes
When configured for
On the inside of the Modem 202T is a simple
Troubleshooting’s easy, too.
An LED control display enables you to confirm modem operation at a glance, and a local and remote test switch enables verification of the link’s integrity.
Along with the Modem 202 or Modem 202T, you’ll receive a cable for making
Distance (Maximum) — 20 mi. (32.2 km) on unloaded lines, depending upon line characteristics
Enclosure — Standard NEMA 1;
Mounting — Hole pattern1⁄4"
Operating Frequency — 1200/2200 Hz (Bell 202 or 1300/2100 ITU V.35) FSK (Frequency Shift Key)
Speed — 300, 600, or 1200 baud halfor full duplex up to 1200 baud simplex
Connectors — (2) terminal blocks, (1) DB9 F
Indicators — (4) LEDs: Data Out, Data In, Carrier, PowerTemperature Tolerance —
External wallmount power supply provided for 110 VAC nominal Size — 1.5"H x 5"W x 9"D (3.8 x 12.7 x 22.9 cm) over mounting flanges
Carrier Detect Delay — 6 or 23 ms
Carrier Frequencies — Mark: 1200 Hz ± 1%; Space: 2200 Hz ± 1%
Line Impedance — 600 ohms ± 10% transformer coupled and transient protected
Modulation — Phase coherent; frequency shift keyed (FSK)Operation —
RTS to CTS Delay — 8, 33, 59, or 219 ms
Speed (Maximum) — Unconditioned line: 1200 bps; Conditioned line: 1800 bps
Transmitter Output Level — Selectable from 0 to
Turnaround Squelch — 8 ms or 159 ms
Connectors — (1) DB25 female (DTE); (1)
Size — 2.3"H x 7"W x 9.6"D (5.8 x 17.8 x 24.4 cm)
202T Modem Rackmount Card
Modem 202 (without Diagnostics)
Modem 202T Standalone (with Diagnostics)
You may also need…
DB9 Extension Cable
DB9 Male to DB25 Female Adapter
3 of 3