Black Box 1300 73 55 66 

1300 73 55 66


Sync Modem Eliminator - DB25 Female/Male

The Sync Modem Eliminator allows two synchronous RS-232 DTE (host) devices to communicate with each other without the need for expensive synchronous modems.

Call for Pricing

Call 1300 734 455 to place order
1 Year Double Diamond™ Warranty (Standard)

Product Features

  • Emulates dialup or leased-line modem service.
  • Installs inline with RS-232 cable.
  • Supports data rates from 7 to 224 kbps, including 56 kbps.
  • Distances supported up to 75 feet (22.8 m) on either side of the connector.
  • Indicator LEDs display TX, RX, and CD.
  • Internal or external clocking. 


  • Runs at 38.4 kbps.
  • Operates full- or half-duplex.
  • Has two DB25 connectors and six LEDs (TX, CTS, and DSR for each of the two ports).

  • We've tailored our SME-4M for your IBM equipment. Use it to regenerate the RS-232 signals, so you can send data up to 100 feet (30.4 m). Then you can put your sync (or async) devices where you want them.

    Use the SME-4M to provide clocking to your system, instead of a pair of modems or line drivers to connect controllers or other systems to your front-end processor. You can monitor the operating status easily with a glance at the front-panel LEDs.

    Because the SME-4M is so small and lightweight, it minimizes logistics problems and simplifies installation and replacement in the field. No special tools are required either. It's definitely designed for do-it-yourself installation.

    Tech Specs

    Connectors (2) DB25 F
    Distance Up to 100 ft. (30.4 m) total
    Indicators (6) LEDs: TX, CTS, DSR for each of the two ports
    Interface RS-232
    Operation Full- or half-duplex
    Power 115 VAC, 60 Hz (230-VAC version on request)
    Protocol Synchronous or asynchronous
    Size 1.8"H x 5.5"W x 8.6"D (4.6 x 14 x 21.8 cm)
    Speed 38.4 kbps
    Weight 2 lb. (0.9 kg)
    This product works with:
  • RS-232 Cable, 25-Conductor, Male/Male (ECM25C)
    The ME251C-R3 works with:
  • 12-Card Rack (RM008).
    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 Diamond

    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 no-questions-asked warranty that protects your Black Box® brand products* from faulty workmanship and defects.

    During the warranty period, Black Box Network Services will repair or replace your faulty equipment 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 1300-734-455.

    ** Certain products may not be eligible.