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Async/Sync RS232 Repeater - DB25 Male to DB25 Female

Repeat async/sync RS232 signals to gain up to an extra 50 ft.


Please call 877-877-2269 for a replacement product or part.
1 Year Double Diamond™ Warranty (Standard)

Product Features

  • Regenerates weak RS-232 signals.
  • Cuts the signal-to-noise ratio in half
  • Data and data-format transparent.
  • Boosts serial transmission up to 100 feet (30.4 m) of cable, provided conditions are similar over the entire run and the booster is in the center.


If your printer is too far away, you may find the transmission from your PC is getting too weak to be recognized by the device on the other side of the line. That’s when you should install the BLACK BOX® RS-232 Serial Line Booster. The booster regenerates the signal at the correct RS-232 level. You get strong transmissions and the convenience of putting the printer where you want it.

The RS-232 Serial Line Booster effectively doubles the range of RS-232 communications by actively receiving and retransmitting the 12 most common signals of the serial RS-232 interface.

Normally, RS-232 communications are limited to 50 feet (15.2 m). But with the RS-232 Line Booster, your data can travel on up to 100 or even 150 feet (30.4 or 45.7 m) of cable if environmental conditions are similar over the entire cable and the booster is in the center of the run. The booster also halves the signal-to-noise ratio, and it’s data and data-format transparent. It can be powered from the interface (Pins 9 and 10) or from its wallmount transformer

Tech Specs

Compliance CSA LR68807; UL® 81J1 E81356
Connectors (1) DB25 F, (1) DB25 M
Dimensions 1.1"H x 3.5"W x 4.5"D (2.8 x 8.9 x 11.4 cm)
Interface RS-232
Leads Supported Pins 2–10, 15, 17, 20–22, 24
Operating Humidity 0 to 95%, non-condensing
Operating Temperature 32 to 114° F (0 to 45° C)
Operationg Full-duplex, point-to-point
Power From Pins 9 and 10 or 115-VAC, 60-Hz, 12-W wallmount transformer (recommended)
Protocol/td> Serial async or sync
Speed 19.2 kbps
Weight 4 lb. (1.8 kg)
This product works with:
The booster should be installed in the middle of the line, not at the beginning or end.
This product works with:
• Standard RS-232 Low-Noise Cable, 25-Conductor (ECM25C)
• AT® Serial Printer Cable (EVMBPC)
• DB25 Female/Female Gender Changer (FA412-R2)
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.


Application Diagram


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 warranty that protects your Black Box® brand products* from accidental damage, including drops, water, and power surges.

The Async/Sync RS232 Repeater DB25 M to DB25 F 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.