opticalCON DUO / duplex LC pinout
opticalCON / LC Fiber for Shows
Show fiber is mostly duplex LC, ruggedized as Neutrik opticalCON DUO: two neutral fiber channels per connection. Equipment assigns transmit and receive, and the patching must cross those paths somewhere so each transmitter reaches a receiver. The craft is polarity, fiber type, polish, and cleanliness.
| Pin | Signal | Notes |
|---|---|---|
| A | Fiber channel 1 | Passive optical path; TX or RX depends on the connected equipment and patching. |
| B | Fiber channel 2 | Second passive path; the connector itself does not assign signal direction. |
What it’s used for
Fiber carries what copper cannot: 12G video across an arena, multichannel audio and control to delay towers, camera backhaul, whole networks on one skinny cable. opticalCON shells put LC ferrules inside a locking, dust-shuttered XLR-sized body that survives truck life; QUAD (4 fibers) and MTP-based versions scale the count.
Duplex links need end-to-end polarity that lands TX on RX. That crossover may be in the equipment breakout, a Type-B duplex patch, or another patch point; opticalCON itself only preserves two fiber channels.
Wiring & termination notes
- Jacket colors declare the glass: yellow is single-mode (OS2, the long-haul default), aqua is OM3 and violet ("Erika violet") OM4 multimode, orange is legacy OM1/OM2. Match fiber type end to end; single-mode optics into multimode glass is a link that "sort of works" and then does not.
- Connector polish matters absolutely: green connectors are APC (8° angled polish) and only mate with APC; blue/standard are UPC. Mating APC to UPC damages ferrules and drops the link.
- Every fiber problem is a dirty connector until proven otherwise. Cap unused ends, clean with proper tools before every mating, and never look into a live fiber.
- Fiber does not bend like copper: respect minimum bend radius, especially at panel entries, or the link budget quietly disappears.
Frequently asked questions
What is the difference between opticalCON and LC?
opticalCON is Neutrik’s ruggedized shell around standard LC ferrules: locking, sealed, and shuttered for touring, and chassis connectors accept bare LC duplex plugs. The optical interface is identical.
Single-mode or multimode for a show?
Single-mode (yellow, OS2) is the default for new touring inventory: it runs any distance a show contains and matches modern 12G and IP gear. Multimode survives in shorter-run and legacy inventories; whichever you run, keep optics and glass matched.
Why does my fiber link work in one direction only?
A polarity problem (TX facing TX somewhere in the path) or one dirty/damaged fiber of the pair. Flip polarity at one patch point and clean everything before condemning hardware.