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Async RS-232 to RS422/485 interface converter DB25 to Terminal Block

Convert async RS232 to RS422/485 at speeds up to 115.2 kbps with distances up to 4 mi. (6.4 km) over CATx cables with opto isolation.


Limited Quantity In Stock
Typically Ships within One Week
Extended Double Diamond™ Warranty Available (3 Additional Year)

*Required field

Product Features

  • Transmit data up to 115 kbps or at distancesup to 4 miles (6.4 km).
  • Operates in point to point or multipoint applications
  • 2- or 4-wire operation, full- or half-duplex
  • async (data leads) only.
  • Selectable RTS-CTS turnaround delay and loopback test feature.
  • Transmitter is always on or controlled by data or RTS.


  • Selectable RTS-CTS turnaround delay and loopback test feature.
  • Features a terminate/unterminate option.
  • Transmitter is always on or controlled by data or RTS.

  • How fast do you want to send data? If your PC has a 16550 UART chip, you can send data at 115.2 kbps with the RS-232 to RS-485/422 Bidirectional Converter Plus! It has a line bias feature that prevents it from receiving line noise as it sends or receives signals. The Converter works in all popular 2- or 4-wire applications. It comes with opto-isolation to guard against power surges. It also supports 64-kbps speeds and has a jumper transmitter that's always on or controlled by RTS.

    Tech Specs

    CE Approval Yes
    Connectors (1) DB25 F (DTE or DCE), (1) 4-screw terminal
    Operation 4-wire, half- or full-duplex; 2-wire half-duplex
    Power 115 VAC, 60 Hz ( 230-VAC, 50-Hz on request)
    Protocol Yes
    Size 4.7"H x 0.6"W x 7.4"D (11.9 x 1.5 x 18.8 cm)

    * Technical specification weight is the unit weight. It is not the packaged shipping weight. For shipping weight, please contact Black Box customer service at 877-877-2269.



    Double Diamond Warranty

    Extended 1 Year Warranty Available

    Protect your purchase with an additional 1 Year Double Diamond™ warranty!
    Cost: $35.33

    Extended 3 Year Warranty Available

    Protect your purchase with an additional 3 Year Double Diamond™ warranty!
    Cost: $70.67


    Double Diamond™ Warranty (Standard)

    Take the risk out of equipment purchases with the Double Diamond™ Warranty from Black Box Network Services.

    The Double Diamond Warranty is our warranty that protects your Black Box® brand products* from accidental damage, including drops, water, and power surges.

    The Async 232 to 422/485 interface converter DB25 to Terminal Block comes with a standard 1 Year Double Diamond™ Warranty (Standard) already included.

    During the warranty period, Black Box Network Services will repair or replace your damaged equipment within one week of receipt at NO CHARGE!*

    Plus, get an Extended Double Diamond Warranty.

    You can also extend your warranty or protect a previously purchased Black Box® brand product** for an additional year—for only 10% of the purchase price! Or, extend your coverage for a full three years for only 20% of the purchase price!

    Ordering an extended warranty is easy: When viewing a product in your shopping cart, just select the one or three years of additional coverage in the dropdown menu under “Warranty Options.” For details, contact Customer Service at 724-746-5500.

    * Warranty subject to certain exclusions and limitations ** Certain products may not be eligible.

    What’s more, we also have a 45-day return policy. Simply call Customer Service for a Return Authorization (RA) number, return your product in new condition and in the original package, and receive a full refund.