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Short-Haul Modem–B Sync (SHM–B Sync), Standalone

Get synchronous data transmission with optical isolation for outdoor runs.


Please call 877-877-2269 for a replacement product or part.
Extended Double Diamond™ Warranty Available (3 Additional Year)

Product Features

  • Great for AS/400® environments!
  • Optical isolation protects your equipment.
  • Sync data travels up to 5 miles (8 km).


Your sync RS-232 devices communicate up to 5 miles (8 km) with the BLACK BOX® SHM-B Sync. For example, if your AS/400 controller and terminal are on different floors—or in different buildings—they can easily talk to each other with a pair of SHM-B Syncs.

Built-in optical isolation protects your data when you run cable underground or between buildings. Run loopback tests right from the front panel. The flip-open housing makes it easy for you to get inside to connect your 4-wire cabling.

Tech Specs

CE Approval 230-VAC version: ME801A-E
Clocking Internal
Connectors (1) DB25 F, (1) 4-screw terminal block
Distance (Maximum) 5 mi. (8 km)
Operation 4-wire full-duplex
Power 115 VAC, 60 Hz (wallmount), 5 watts
Protocol Synchronous
Size 1.5"H x 4.3"W x 4.5"D (3.8 x 10.9 x 11.4 cm)
Speed (Maximum) 19.2 kbps
This product works with:
• GigaBase 350 CAT5e, 350-MHz Bulk Cables, 4-Pair (EYN851A-PB-1000, etc.)
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.


Double Diamond Warranty

Extended 1 Year Warranty Available

Protect your purchase with an additional 1 Year Double Diamond™ warranty!
Cost: $19.32

Extended 3 Year Warranty Available

Protect your purchase with an additional 3 Year Double Diamond™ warranty!
Cost: $38.63


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 Short-Haul Modem–B Sync (SHM–B Sync), Standalone comes with a standard 1 YEAR Doublediamond™ Warranty (Standard) warranty 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.