Optical transport and troubleshooting
SDI over fiber: formats, endpoints and converters
SDI over fiber is an option for routes beyond the intended reach of the system’s coaxial cable. Select the link around the actual format and endpoints. An electrical-to-optical converter, a scaler and an IP video system perform different functions.
Define what must reach the destination
Record resolution, exact frame rate, interlaced or progressive scanning, SDI rate and Level A/B where applicable. Add embedded audio, ancillary data and return requirements. A “4K” label alone does not define the full format.
Map SDI source → optical transmitter → fiber → optical receiver → SDI destination. This is a functional sketch. If resolution or frame-rate conversion is required, specify that function explicitly; do not assume fiber transport provides it.
Identify the converter variant
As an example, AJA FiDO-TR-12G combines an SDI-to-fiber channel with a fiber-to-SDI channel using duplex single-mode LC connectivity. Its data sheet lists 12G/6G/3G/HD/SD-SDI support; the manual distinguishes transmitter, receiver and two-channel variants.
Its duplex connection differs from the single-strand BiDi link discussed elsewhere. Select each end by function and check fiber, connectors, wavelengths and optical range. Two BNC outputs do not necessarily mean two independent signals; review the model’s diagram.
Prepare an end-to-end check
Check the data sheets for formats supported by the source, converters and destination, along with power supplies and local coax sections. When combining manufacturers, check that the documentation supports both the optical connection and the signal format. A test at another format does not verify the one you will use at the event.
Compare a suitable SDI transport pair, transport with format conversion or an IP architecture if the project requires it. For a proposed test, record the planned format, audio, route and duration, and distinguish the plan from a test actually performed.
Information for a link review
| Item | What to record | Purpose |
|---|---|---|
| Signal | Resolution, frame rate, rate, level and required audio/data | Check formats throughout the chain |
| Directions and channels | Outbound and return signal counts; each port’s function | Distinguish loop-through, duplication and independent channels |
| Optical endpoints | Full part numbers, fiber, connectors and TX/RX limits | Review interoperability and route power budget |
Before approaching an optical connection
Do not look into optical ports or fiber ends, even when no light is visible. Inspection, cleaning and measurement require the manufacturer’s tools and procedures. If the assembly is hybrid and also carries power, identify the complete system and arrange work with qualified personnel.
Technical questions
Can the receiver connect to a network switch because it uses SFP?
Do not infer that from module shape. Identify optical SDI, Ethernet or another protocol and use the system’s intended endpoints.
Will a 12G converter automatically downconvert for an HD device?
Do not assume scaling or frame-rate conversion. Confirm a specific conversion function or supply a format supported throughout the chain.
Can any two brands work if the wavelength matches?
Wavelength is only one requirement. Review protocol, rate, optical functions, sensitivity, overload and documented endpoint support.
Further documentation
- AJA — FiDO-TR-12G — FiDO-TR-12G example with specific interfaces and channels.
- AJA — FiDO 12G Series Installation and Operation Guide — Manual v1.4: 12G family models and connections.
- Fluke Networks — 5 Vital Safety Rules for Fiber Optic Cables — Optical safety and suitable tools.
Third-party field experience: useful questions, without specification or safety authority.
- VIDEOENGINEERING — SFP (+) video fiber connector compatibility — Question about converters and modules from different manufacturers.
Continue your review
- HDMI over fiber: direction, power and EDID
- Black screen or no picture at an event: trace the video signal
- Video switchers, media servers and LED processing
A project to compare
This project shows an LED installation in a studio. The photos help discuss placement, integration and system access.