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 DB9 to Terminal Block

Convert async RS232 to RS422/485 at speeds up to 19.2 kbps with distances up to 4000 ft over CATx cables in industrial environments with DIN Rail mounting.


51 In Stock
Same Day Shipping (before 5PM ET)
Extended Double Diamond™ Warranty Available (3 Additional Year)

*Required field

Product Features

  • Optically isolates and converts unbalanced half- or full-duplex RS-232 signals to optically isolated and balanced full-duplex RS-422 or 2-wire half- or 4-wire full-duplex RS-485.
  • Switch-selectable data rates between 2400 bps and 19.2 kbps.
  • Conveniently mounts on a DIN rail.
  • Power up to six of the converters with our optional DIN Rail 12-VDC Power Supply (PSD100).


Convert async RS232 to RS422/485 at speeds up to 19.2 kbps with distances up to 4000 ft over CATx cables. These devices are great for connecting RS232 devices into an existing RS422/485 environment in factory automation, building automation, and process automation. They can be mounted using DIN Rail and can withstand operating temperatures of -40 to 176 degrees F (-40 to 80 C).

Tech Specs

CE Approval Yes
Connectors (2) 6-position terminal blocks, (1) DB9 F (DCE)
Distance (Maximum) 4000 ft. (1219.2 m)
Indicators (3) LEDs: (1) RS-485 transmit data, (1) RS-485 receive data, (1) power
Isolation 2000 VAC optical isolation of data signals and ground
Operating Environment Temperature: -40 to +176° F (-40 to +80° C); Humidity: Up to 95% noncondensing
Operation RS-232: Half- or full-duplex; RS-485: 2-wire half-duplex or 4-wire full-duplex; RS-422: Full-duplex
Power 10-30 VDC, 100 mA
Size 1"H x 3.1"W x 4.2"D (2.5 x 7.9 x 10.7 cm)
Speed 2400 bps to 19.2 kbps, switch-selectable; other rates available between 1200 bps and 115.2 kbps
Surge Suppression Bidirectional avalanche breakdown device: 7.5 V; Peak power dissipation: 500 W; Clamping time: <1 psec
This product works with:
This product works with:
  • DIN Rail (DR100)
  • DIN Rail 12-VDC Power Supply (PSD100) for powering up to six converters
  • DB25 to Terminal Block Adapter (IC980)
  • DB9 Male/Female Serial Extension Cables (BC00200, etc.)
  • Individually Shielded Low-Capacitance Cable—Extra Distance, 4 Conductors (ERN04A)
    Questions? Contact our FREE Tech Support.

    * 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.

  • Support


    Double Diamond Warranty

    Extended 1 Year Warranty Available

    Protect your purchase with an additional 1 Year Double Diamond™ warranty!
    Cost: $20.08

    Extended 3 Year Warranty Available

    Protect your purchase with an additional 3 Year Double Diamond™ warranty!
    Cost: $40.17


    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 RS232 to RS422/485 interface converter DB9 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.