UHD-FOM40-K Overview and Use Cases

What Is the UHD-FOM40-K?

The OREI UHD-FOM40-K is a 4K@60Hz HDMI over 1G IP fiber extender kit. It sends HDMI video and audio over single-mode optical fiber up to 40km.

The kit includes a Transmitter and Receiver. The HDMI source connects to HDMI IN on the Transmitter, the display connects to HDMI OUT on the Receiver, and an optical fiber cable connects the Transmitter to the Receiver through SFP optical modules.

The UHD-FOM40-K supports HDMI 2.0 and HDCP 1.4 / HDCP 2.2, with a video bandwidth of 18Gbps. It supports video resolutions up to 3840x2160@60Hz, one-to-one connection, one-to-many connection through a gigabit fiber switch, switch cascading, HDMI loop out on the Transmitter, IR passback, RS-232 pass-through, 3.5mm audio embedding on the Transmitter, 3.5mm audio output on the Receiver, firmware upgrade through Micro USB, and transmission distance up to 40km over single-mode optical fiber.

The UHD-FOM40-K is useful for long-distance AV installations, security rooms, control rooms, campuses, conference rooms, houses of worship, education, commercial displays, and installations where HDMI needs to be extended over fiber.

IMPORTANT — UHD-FOM40-K Supports 4K@60Hz

The UHD-FOM40-K supports video resolutions up to 3840x2160@60Hz.

Supported resolutions include:

To get 4K@60Hz, the HDMI source, display, HDMI cables, SFP optical modules, fiber cable, and switch setup must support the required signal.

IMPORTANT — Extends up to 40km Over Single-Mode Fiber

The UHD-FOM40-K supports optical fiber transmission up to 40km.

For best performance, use the correct single-mode optical fiber cable and the included SFP optical modules.

Poor fiber cable quality, wrong fiber type, dirty fiber connector, incorrect SFP module placement, or damaged fiber may cause no signal or unstable video.

IMPORTANT — Uses SFP Optical Modules

The package includes two SFP optical modules.

Do not swap the SFP modules.

If the units do not connect, confirm the correct SFP module is installed in the correct unit and that the fiber cable is connected properly.

IMPORTANT — Supports One-to-One and One-to-Many Setups

The UHD-FOM40-K supports:

For one-to-many or switch cascading setups, use gigabit fiber switches.

The manual recommends using gigabit / 1000Mbps switches for LAN transmission and says 100Mbps switches should not be mixed with gigabit switches when cascading.

IMPORTANT — This Is Not a Standard CAT Cable Extender

The UHD-FOM40-K uses optical fiber through SFP modules.

It is not a standard CAT 6 HDMI extender.

Do not connect the SFP / fiber ports directly to standard RJ45 Ethernet ports.

For one-to-many setups, use the correct gigabit fiber switch setup shown in the connection diagram.

IMPORTANT — HDMI Loop Out Is on the Transmitter

The Transmitter includes HDMI OUT.

This HDMI OUT port is used to connect a local display near the HDMI source.

Example setup:

This is useful when the source needs to be viewed locally and also sent over fiber to a remote display.

IMPORTANT — IR Passback Is Supported

The UHD-FOM40-K supports IR passback from the Receiver side to the Transmitter side.

This allows the user near the remote display to control the HDMI source near the Transmitter.

Typical setup:

• Connect the IR Blaster cable to IR OUT on the Transmitter
• Place the IR Blaster near the source device IR sensor
• Connect the IR Receiver cable to IR IN on the Receiver
• Place the IR Receiver near the remote display where the source remote can point

The supported IR frequency is 20kHz to 60kHz.

IMPORTANT — RS-232 Pass-Through Is Supported

The UHD-FOM40-K supports RS-232 pass-through using GND / RXD / TXD terminal wiring.

Supported RS-232 baud rates include:

The default baud rate is 115200.

Use RS-232 for projector control, display control, matrix control, or control system integration.

IMPORTANT — Audio Embedding and Audio Output Are Supported

The Transmitter includes 3.5mm L/R IN.

The Receiver includes 3.5mm L/R OUT.

The manual lists HDMI OUT audio as LPCM 2.0 and 3.5mm L/R output as PCM.

If there is no audio, set the HDMI source audio output to PCM / Stereo.

IMPORTANT — Both Units Need Power

The Transmitter and Receiver each require DC 5V/2A power.

The package contents list one DC 5V/2A power adapter. Confirm the package configuration before installation and make sure both required power connections are properly supplied.

IMPORTANT — Firmware Upgrade Through Micro USB

Both the Transmitter and Receiver include a Micro USB interface.

This port is used for firmware upgrade.

Firmware updates are not needed for normal setup. Use firmware only when provided by OREI support or from the official product support page.

IMPORTANT — 24-Hour Operation Is Supported

The manual lists support for steady 24-hour operation.

This makes the UHD-FOM40-K suitable for continuous display environments such as:

• Security monitoring
• Control rooms
• Digital signage
• Commercial display systems
• Education
• Meeting rooms
• Long-distance AV distribution

For best reliability, keep both units ventilated and use proper surge protection.

Ports and Panel Layout

Step-by-Step Setup — One-to-One Connection

1. Insert the correct SFP optical module into the Transmitter.
2. Insert the correct SFP optical module into the Receiver.
3. Connect the HDMI source device to HDMI IN on the Transmitter. 
   Examples include a PC, media player, Blu-ray player, cable box, HDMI matrix output, or HDMI switch output.
4. Connect a local display to HDMI OUT on the Transmitter if needed.
5. Connect the optical fiber cable from the Transmitter SFP output to the Receiver SFP input.
6. Connect HDMI OUT on the Receiver to the remote display.
7. Connect DC 5V/2A power to the Transmitter.
8. Connect DC 5V/2A power to the Receiver.
9. If using IR control, connect the IR Blaster cable to IR OUT on the Transmitter.
10. Connect the IR Receiver cable to IR IN on the Receiver.
11. If using RS-232, connect the RS-232 terminal block wiring on both units.
12. If using audio embedding, connect the 3.5mm audio source to L/R IN on the Transmitter.
13. If using audio output, connect L/R OUT on the Receiver to speakers, amplifier, or audio system.
14. Power on the HDMI source, display, Transmitter, Receiver, and connected devices.
15. Check the power and status indicators.
16. Test video, audio, HDMI loop out, IR, and RS-232.

Step-by-Step Setup — One-to-Many Connection

1. Connect the HDMI source to HDMI IN on the Transmitter.
2. Connect the Transmitter SFP output to a gigabit fiber switch.
3. Connect multiple Receivers through the gigabit fiber switch.
4. Connect each Receiver HDMI OUT to a display.
5. Power the Transmitter, Receivers, and switch.
6. Confirm each Receiver has link status and HDMI output.
7. Test video on all displays.

Important: The same source signal is sent to the connected displays. This does not create separate independent video outputs.

Step-by-Step Setup — Switch Cascading

1. Connect the HDMI source to the Transmitter.
2. Connect the Transmitter to the first gigabit fiber switch.
3. Cascade additional gigabit fiber switches if needed.
4. Connect Receivers to the downstream switch system.
5. Connect each Receiver to an HDMI display.
6. Power all devices.
7. Confirm the status indicators and video output.

Do not mix 100Mbps switches with gigabit switches when cascading.

Fiber Cable Requirement — Critical

Use single-mode optical fiber cable for the listed 40km distance.

Poor fiber installation may cause:

• No connection
• Status light off
• Slow flashing status light
• No video
• Video dropouts
• Audio dropouts
• IR control failure
• RS-232 pass-through failure
• Reduced transmission distance

Keep fiber connectors clean and avoid sharp bends.

HDMI Cable Requirement — Critical

The manual lists HDMI cable length as less than or equal to 5m.

Use high-quality HDMI cables for:

• Source to Transmitter HDMI IN
• Transmitter HDMI OUT to local display
• Receiver HDMI OUT to remote display

Poor HDMI cables may cause:

• No video
• Flickering
• Black screen
• 4K@60Hz not working
• Audio dropouts
• HDCP handshake issues
• Wrong resolution

For troubleshooting, test the HDMI source directly with the display first.

Power Requirement — Critical

The UHD-FOM40-K uses DC 5V/2A power.

If a unit does not power on, check the power adapter, outlet, and DC 5V connection.

Understanding the Status Indicator

The status indicator shows connection and video transmission state.

For best performance, use a gigabit connection.

Understanding HDMI Loop Out

The HDMI OUT port on the Transmitter is used for local display connection.

This lets the HDMI source show on a nearby display while also being extended over fiber to the Receiver.

The local and remote displays show the same HDMI source.

Understanding Audio Embedding

The Transmitter L/R IN port allows an external 3.5mm audio source to be connected.

This can be used when audio needs to be embedded into the extender system from a separate analog source.

Understanding Audio Output

The Receiver L/R OUT port outputs PCM audio.

This can connect to:

• Powered speakers
• Amplifier
• Audio system
• External sound system

If audio does not play, set the source to PCM / Stereo.

Understanding IR Passback

IR passback sends remote-control signals from the Receiver side back to the Transmitter side.

Typical setup:

Use the source device remote, not the TV remote, when controlling the HDMI source.

Understanding RS-232 Pass-Through

RS-232 pass-through sends control commands between the Transmitter and Receiver.

Use it for:

• Projector control
• Display control
• Matrix control
• Control processor integration
• Automation systems

The RS-232 terminal block uses GND / RXD / TXD wiring.

Supported Video and Audio

The UHD-FOM40-K supports video formats including:

Supported audio:

Supported Technical Specifications

What Source Devices Is the UHD-FOM40-K Compatible With?

The UHD-FOM40-K is compatible with HDMI source devices such as:

• Desktop PCs
• Laptops
• Media players
• Blu-ray players
• Cable boxes
• Satellite receivers
• HDMI matrix outputs
• HDMI switch outputs
• DVRs
• NVRs
• AV receivers with HDMI output

The source must output a supported HDMI resolution up to 4K@60Hz.

What Displays Is the UHD-FOM40-K Compatible With?

The UHD-FOM40-K can connect to HDMI displays such as:

• 4K TVs
• UHD displays
• Projectors
• Monitors
• Commercial displays
• Digital signage displays
• Control room displays
• Conference room displays
• Classroom displays

For 4K@60Hz, the display must support 4K@60Hz input.

What Audio Devices Is the UHD-FOM40-K Compatible With?

The Receiver L/R OUT can connect to:

• Powered speakers
• Amplifiers
• Audio systems
• External speaker systems
• Audio input devices

The Transmitter L/R IN can connect to:

• Audio players
• MP3 players
• Analog audio source devices

For best compatibility, use PCM / Stereo audio.

Frequently Asked Questions

Q: What is the OREI UHD-FOM40-K used for? 
A: The UHD-FOM40-K is used to extend 4K@60Hz HDMI video, audio, IR, and RS-232 over single-mode optical fiber up to 40km.

Q: Does the UHD-FOM40-K support 4K@60Hz? 
A: Yes. It supports up to 3840x2160@60Hz.

Q: Does the UHD-FOM40-K support 8K? 
A: No. It supports up to 4K@60Hz.

Q: What HDMI version does it support? 
A: It supports HDMI 2.0.

Q: What HDCP version does it support? 
A: It supports HDCP 1.4 and HDCP 2.2.

Q: What video bandwidth does it support? 
A: It supports 18Gbps video bandwidth.

Q: How far can it extend HDMI? 
A: It supports optical fiber transmission up to 40km over single-mode fiber.

Q: What fiber cable should I use? 
A: Use single-mode optical fiber cable with SFP to LC connection.

Q: Which SFP module goes in the Transmitter? 
A: Use the SFP optical module marked T1310nm / R1550nm on the Transmitter side.

Q: Which SFP module goes in the Receiver? 
A: Use the SFP optical module marked T1550nm / R1310nm on the Receiver side.

Q: Can I swap the SFP modules? 
A: No. Keep the Transmitter and Receiver SFP modules in their correct units.

Q: Does it support one-to-many distribution? 
A: Yes. It supports one-to-many connection through a gigabit fiber switch.

Q: Does it support switch cascading? 
A: Yes. Switch cascading is supported.

Q: What type of switch should I use? 
A: Use a gigabit / 1000Mbps fiber switch.

Q: Can I mix 100Mbps switches with gigabit switches? 
A: No. The manual says 100Mbps switches should not be mixed with gigabit switches when cascading.

Q: Does the Transmitter have HDMI loop out? 
A: Yes. The Transmitter has HDMI OUT for local display connection.

Q: What is HDMI loop out used for? 
A: It lets you connect a local display near the source while also sending the same HDMI signal over fiber to the Receiver.

Q: Does it support IR control? 
A: Yes. It supports IR passback.

Q: What IR frequency is supported? 
A: It supports 20kHz to 60kHz.

Q: What is the IR receiving range? 
A: The manual lists IR receiving range up to 5m.

Q: Does it support RS-232? 
A: Yes. It supports RS-232 pass-through.

Q: What is the default RS-232 baud rate? 
A: The default baud rate is 115200.

Q: What other RS-232 baud rates are supported? 
A: Supported baud rates include 2400, 4800, 9600, 19200, 38400, 57600, and 115200.

Q: Does it support audio embedding? 
A: Yes. The Transmitter has 3.5mm L/R IN for audio embedding.

Q: Does the Receiver have audio output? 
A: Yes. The Receiver has 3.5mm L/R OUT.

Q: What audio format does HDMI OUT support? 
A: The manual lists HDMI OUT audio as LPCM 2.0.

Q: What audio format does 3.5mm L/R OUT support? 
A: The manual lists 3.5mm L/R output as PCM.

Q: Is it zero latency? 
A: No. The manual lists transmission latency as 70–180ms.

Q: What should I do if there is no video? 
A: Check power on both units, confirm SFP modules are installed correctly, check the fiber cable, test the HDMI source directly with the display, and try a shorter HDMI cable.

Q: What should I do if the status light is off? 
A: The Transmitter and Receiver have not established a connection. Check the SFP modules, fiber cable, and switch path.

Q: What should I do if the status light is slow flashing? 
A: The units are connected, but no video data is transmitting over gigabit Ethernet. Check the HDMI source input and source output settings.

Q: What should I do if the status light is quick flashing? 
A: The units are connected but only detecting 100M Ethernet behavior. Use a gigabit switch and confirm the fiber network path supports gigabit.

Q: What should I do if audio does not work? 
A: Set the source audio to PCM / Stereo, check HDMI output audio, and confirm the 3.5mm L/R OUT is connected to the audio device.

Q: What should I do if IR control does not work? 
A: Confirm the IR Blaster is connected to Transmitter IR OUT, the IR Receiver is connected to Receiver IR IN, and the IR Blaster is placed near the source device IR sensor.

Q: What should I do if RS-232 does not work? 
A: Check the GND / RXD / TXD wiring and make sure both devices use a supported baud rate.

Q: Does the UHD-FOM40-K need external power? 
A: Yes. The Transmitter and Receiver require DC 5V/2A power.