Black Box 1-800-316-7107 


Helping you is our priority at Black Box.

We're committed to providing the best customer service in the industry. We're here for you, 24/7, 365.

We'll call you

A technical expert will call you shortly.

Submit Connecting call...

Call Us

Customer Sales & Service Support

Black Box Brand Product Support

IT Services & Voice Support

Send us a FAX


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.


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.


  • Features a terminate/unterminate option.
  • Transmitter is always on or controlled by data or RTS.

  • The RS-232 to RS-422 Bidirectional Converter 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)
    Protocol Asynchronous
    Size 1.8"H x 5.5"W x 8.4"D (4.6 x 14 x 21.3 cm);
    This product works with:

    * 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: $37.70

    Extended 3 Year Warranty Available

    Protect your purchase with an additional 3 Year Double Diamond™ warranty!
    Cost: $75.41


    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.