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Bell 202 Modems -- Bell 202T Modems

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Rack Mount for 16 Bell 202 modems, Bell 202T modems or ITU V.23 Modems

Rack Mount Bell 202 Modem

Stand alone version of the Bell 202 Modem, Bell 202T modem and the ITU V.23 modem

Bell 202 Modem - Box

Applied Systems Engineering, Inc, has been manufacturing Bell 202 modems, Bell 202T modems, and ITU V.23 modems for over 10 years. Our customers include Power Utilities, Oil and Gas SCADA, Water treatment, SCADA equipment manufacturers, Engineering firms and many others.

The Bell 202 modem standard was developed by AT&T and was formally released in 1976. This standard allowed for very reliable low speed multi drop communications to occur over standard copper wires. This site has been created to help you find detailed information about the Bell 202 Modem, the Bell 202T modem variation, and the European standard, ITU or CCITT V.23 modem specifications and standards.

These modems have been designed with many commonly requested features including 900Hz soft-carrier turnoff, LED indicators, digital control over most timing parameters (in 1 millisecond increments), transmit levels from 0 to -31db, and input power from 5 to 160 VDC. The primary modem circuitry is based on commercially available ICs with many years of field proven operation.

All Bell modems are available in a 19" rack configuration with a 16-slot custom back plane, or stand alone where the modem is packaged in a metal box. For Remote Terminal Unit (RTU) manufacturers, a low-cost "board only" version can mount directly in the remote unit.


You may contact us in Campbell, CA by phone at 408-364-0500, fax to 408-364-0550, or via email at

Normal business hours are 9:00AM to 6:00PM Pacific Time, M - F.

Applied Systems Engineering, Inc.
1671 Dell Avenue, Suite 200
Campbell, California 95008
Phone: (408) 364-0500 • Fax: (408) 364-0550


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If you would like additional information on any of the ASE products or would like to discuss your specific requirements with a sales engineer, you can call directly or fax/e-mail the information about your requirement and a sales engineer will contact you.