Bell 202T FSK Modem

Bell 202T modem using Frequency Shift Keying (FSK)
Network Control PC software configuration and Redundant Power Supplies 

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Software Configured

Configurable through Windows based software

DM-15 - Bell 202T Modem

  • 2 and 4 Wire Operation
  • DM-15 configured in Bell 202T mode
  • Operates as point-to-point and multi-drop configuration (party line)
  • Configurable through Windows™ based software
  • 19" Rack or mounted or stand-alone

The software configuration utility allows the user to:


The DM-15 modem is a single card modem with a back termination card for 19" rack installation or the stand-alone enclosure.

The modem operates in Bell 202T mode using Frequency Shift Keying (FSK) and are designed for asynchronous or bit oriented data operations at 1200 baud.

The modem provides half-duplex communication on 2-wire private line circuits or full duplex communication on 4-wire private line circuits.

The I/O back termination card provides connectivity to the DC power supply, 1 x RS 232 DCE and VF communication channels. The back termination card is suitable for mounting options available.

The configuration of the modem cards is downloadable through the RS 232 port using the DM-15 utility.

The DM-15 modem is a Bell 202T Frequency Shift Keyed (FSK) modem designed for asynchronous byte or bit oriented
communications up to 1200 Baud.

This modem provides half-duplex communications on 2-wire private line circuits or full duplex communication on 4-wire private line circuits.


The Bell 202T modem is designed for use in a single EuroCard 19'' sub-rack system. This rack can accommodate 17 Bell 202T modems as well as 2 redundant power supplies for the system.

The rear communications interface consists of one DB-9 female connector for serial connection to each modem module. The 2/4-wire interface is provided for on an RJ-11 4/4 connector.


Configuration is achieved by means of the DB-9 (female) serial interface on the front panel of the modem using the user-friendly Windows based software configuration utility.

When a PC is plugged into this port, (and RTS is asserted) the modem will enter configuration mode automatically. Once the PC plug is removed, the modem will restart. This prevents the necessity to withdraw each modem from the rack for configuration.

This configuration utility runs under Windows 95™, Windows 98™, Windows NT™, Windows 2000™.

The software configuration utility allows the user to:

The following parameters are available for configuration using the software utility:


Technical Characteristics





Number of Serial Ports

1 Channel

Type of Interface

RS 232 CCITT V.28

Data Transfer Rate

1200 Baud

Flow Control


Type of Connection

Standard 9 pin serial connection



Number of channels

1 or 2 Channels


5 kV through matching transformer


600 Ohm, 10 kOhm ( high impedance)

Transmitter output range

- 4 to – 20 dBm

Minimum output power

-20 dBm

Receiver Sensitivity

Four ranges, 0 to -15dBm, -5 to -20dBm, -15 to -25 dBm, and -20 to -40dBm

Test facilities

4 x 2mm test jacks and line disconnect switches



Input Range

+12 Vdc and –12 Vdc

Power Consumption

50 mA @ +12 Vdc & 8 mA at –12Vdc



Process Indications

1 x Power On LED Indication


4 x DCE Interface LED Indication for TXD, CTS, RXD, DCD



Radiated Emission

EN 55 022 Class A (formerly CISPR –022)



Protection Class

IP 00 (IP 20 in rack)

Ambient temperature


· = Continuous Operation

-10° to +60° C

· = Transportation and storage

-40° to +70° C

Relative Humidity




Dimensions (W * H * D)

5 hp x 3U (25.4 x 133.3 x 170 mm)


Approx. 160 grams



Related pages

301-924-7400 EXT 25

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