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Opto-Isolator II

Stop ground loops of up to 2500 volts from wreaking havoc on your system.


Please call 877-877-2269 for a replacement product or part.
NONE DoubleDiamond™ Warranty (Standard)

Product Features

  • Internal fiber optic air gap prevents ground loops.
  • Data signals are converted to line pulses inside the Opto-Isolator and continue along the circuit.


Linking two devices powered by separate AC sources can create the potential for a ground-loop surge—a damaging electrical condition that can destroy your computer and wipe out data. But BLACK BOX® Opto-Isolators interrupt that lethal pathway by completing the connection between the two devices with an internal fiber optic link.

Data signals, converted to light pulses inside the Isolator, continue along on the circuit. But the fiber optic air gap stops ground loops from wreaking havoc with your hardware.

Our Opto-Isolator II has an RS-422/485 interface and a 4-screw terminal instead of RJ-45 ports. It protects lines up to 2000 feet (609.6 m).

Tech Specs

cUL 0
UL 0
Connectors (1) 4-screw terminal
Interface RS-422/485
Power From the Receive data pair
Protocol Asynchronous
Size 1"H x 2.3"W x 2.3"D (2.5 x 5.8 x 5.8 cm)
Speed Up to 19.2 kbps
Weight 0.1 lb. (<0.1 kg)
NOTE: To protect RS-232 to RS-422/485 lines, see our RS-232↔RS-485/422 Converter Plus with Opto-Isolation (IC109A-R3).

These products work with:
• Standard RS-232 Low-Noise Cable, 25-Conductor (ECM25C)
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 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 Opto-Isolator II comes with a standard NONE 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.