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RS-232 async to sync converter product picture

Features / Benefits

  • Interface - RS-232, DB-25 Male (To DTE) and RS-449/RS-530 Female DB-25 (To DCE)
  • Data Rates - Synchronous to 38.4bps and supports 3/4 baud rates
  • Synchronous data rates are automatically adjusted
  • Line Powered or Optional DC Power
  • Switch selectable - 8 to 11 bits
  • CCITT V.14 and V.22 compliant
  • Supports full and half duplex operation
  • Compact and Easy To Install


The ASC-422 Async to Sync Converter is designed to allow RS-232 async terminal equipment to transmit over higher speed V.11 compliant sync modems. The ASC-422 devices are used in pairs, one at each end of the communication link or in multiples as when used in a multi-drop communication link.

The ASC-422 supports async data of 8, 9, 10 and 11 bits, including the start and stop bit. Standard data rates from 1200 to 38.4bps and 3/4 rates of 900 to 28.8bps are supported for synchronous transmission. The ASC-422 automatically adjusts the sync data rate to match the DTE's output rate, no data rate strapping is required.

Stop bit reduction is provided when the async data rate is faster than the sync data rate, ensuring reliable data communications.

Utilizing new silicon chip technology this device derives its power from both the async and sync interfaces, thus no power supply is required. This equates to savings in your power requirements and with battery backup at your data center.

The ASC-422 is housed in a sturdy metal enclosure and will provide in excess of 100,000 hours of reliable service. The ASC-422 has a three year warranty and a 24 hour turnaround on warranty repairs.

RS-232 asynchronous to synchronous converter network diagram


Application RS-232 aync to sync converter allows async terminal to sync RS-422/RS-530 modem
Conversion, full or half duplex
Capacity One sync RS-422/530 modem
One async RS-232 terminal
Interface RS-232 to DTE
RS-422 or RS-530 to DCE
Data Format Data transparent at all data rates; Conforms to CCITT V.14 and V.22, (Async to Sync conversion)
Data Rates 1200 to 38.4bps; 900 to 28.8bps
Switches Provided for async data set-up, stop bit reduction and signal to frame ground
Power Source Line Powered from existing equipment -
Draws 8ma - No AC power required
Environmental Operating Temperature . .32º to 122º F (0º to 50º C)

Relative Humidity.. . . . . . .5 to 95% Non-Condensing

Altitude. . . . . . . . . . . . . ... .0 to 10,000 feet

Dimensions Height ....... 0.50 inches (1.27 cm)

Width ........ 1.75 inches (4.44 cm)

Length ....... 3.90 inches (9.91 cm)

Weight 1 pound (0.457Kg)
Warranty Three Years, Return To Factory
Ordering Information Model: ASC-422 / DC Option
Description: Async to Sync converter with DC
Included with each unit: 1) Installation Guide