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Async RS232 RS422 RS-485 Extender Fiber Terminal Block ST Single-Mode

Extend RS232, RS422 or RS485 protocols over multimode fiber so different types of equipment can talk to one another in point to point or multipoint environments.


Limited Quantity In Stock
Typically Ships within One Week
3 Year Double Diamond™ Warranty (Standard)

*Required field

Product Features

  • Communicate signals in a point-to-point or ring topology.
  • Communicate signals in a point-to-point or ring topology.
  • Ideal for fiber applications that use different interface protocols.
  • Extended ambient operating range
  • Data-derived or RTS transmit/receive switching (RS-485)
  • Indicator LEDS monitor signal and power
  • End-to-end protocol conversion—no separate box is needed.
  • Speeds up to 10 Mbps for RS-422 and RS-485, 200-kbps for RS-232.


Extend RS232, RS422 or RS485 protocols over multimode fiber so different types of equipment can talk to one another in point to point or multipoint environments. Serial extenders work well in factory automation, building automation, and process automation where PLC's with RS232, RS422 or RS485 interfaces are used to control devices. The ability to extend the distance to their devices over fiber while also adding protection from electrical interference which can be caused by large motors which are prevalent in these environments is very beneficial.

Use fiber instead of copper to send your RS-232, RS-422, and RS-485 data—and do so without having to route it through protocol converters.

Universal Fiber Optic Line Driver Transceivers enable you to transmit and receive the signals over fiber optic cabling in both point-to-point or drop-and-repeat topologies. You can even mix protocols. For instance, you can set one transceiver to interface with an RS-232 device at one end and another to interface with an RS-485 device at the opposite end. There's no need for a converter box at either end of the fiber link!

Universal Fiber Optic Line Driver Transceivers also offer a wide range of speeds and distances—up to 21.75 miles (35 km) with the single-mode version.

Tech Specs

CE Yes
Connectors (1) terminal block, (1) pair of ST®
Dimensions 1.3"H x 3.5"W x 4"D (3.3 x 8.9 x 10.2 cm)
Distance 35 km (21.75 mi.)
Operating Wavelength Single-mode 1310 nm
Operation Simplex, full or half-duplex, point-to-point or multipoint
Power Input 100 to 240 VAC, 50/60 Hz
Power Output 12 VDC
Protocol Asynchronous
Signal Interface 2- or 4-wire: RS-232, RS-422, RS-485
Speed RS-422, RS-485: Low speed: 2.1 Mbps; High speed: 10 Mbps; RS-232: 200 kbps
Must be used in pairs.

* 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 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 accidental damage, including drops, water, and power surges.

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 787-767-3500.

** Certain products may not be eligible.

What’s more, we also have a 45-day, no-questions-asked 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.