UHD18-EXB400-K Overview and Use Cases

What Is the UHD18-EXB400-K?

The OREI UHD18-EXB400-K is an 18Gbps 1x8 HDMI HDBaseT splitter extender kit. It distributes one HDMI source signal to up to eight remote HDMI displays over CAT6 / CAT6a / CAT7 cable, with an additional HDMI loop out on the Transmitter for a local display.

The kit includes one 18Gbps HDMI 1x8 HDBaseT splitter Transmitter and eight HDBaseT Receivers. The HDMI source connects to HDMI IN on the Transmitter, the local display can connect to HDMI LOOP OUT, and each remote display connects through an included HDBaseT Receiver.

The UHD18-EXB400-K supports HDMI 2.0b and HDCP 2.2 / 1.x, with a video bandwidth of 18Gbps. It supports video resolutions up to 4K@60Hz 4:4:4, HDR, HDR10+, HLG, Dolby Vision, HDMI loop out, eight HDBaseT outputs, IR pass-through, RS-232 pass-through, digital and analog audio de-embedding, advanced EDID management, ASCII command control, and one-way PoC from the Transmitter to the Receivers. It extends 4K@60Hz up to 120m / 394ft and 1080p@60Hz up to 150m / 492ft over a single CAT6 / CAT6a / CAT7 cable. 

The UHD18-EXB400-K is useful for restaurants, bars, churches, classrooms, conference rooms, retail displays, control rooms, digital signage, sports bars, commercial AV installations, and any setup where one HDMI source needs to be shown on up to eight long-distance displays.

IMPORTANT — UHD18-EXB400-K Is a 1x8 HDBaseT Splitter Extender

The UHD18-EXB400-K sends one HDMI source to up to eight remote displays.

This product duplicates one HDMI source to multiple displays. It does not create separate independent video outputs or extended desktop screens.

IMPORTANT — Supports 4K@60Hz 4:4:4

The UHD18-EXB400-K supports video resolutions up to 4K@60Hz 4:4:4.

Supported video features include:

To get 4K@60Hz 4:4:4, the HDMI source, displays, HDMI cables, CAT cable, and EDID setting must all support the required signal.

IMPORTANT — Maximum Distance Depends on Resolution

The UHD18-EXB400-K supports different transmission distances depending on resolution.

For best performance, use high-quality CAT6 / CAT6a / CAT7 cable.

Poor cable quality, damaged connectors, couplers, patch panels, or poor terminations may reduce distance or cause signal instability.

IMPORTANT — Use Direct CAT Cable Connections

Each HDBaseT Receiver should be connected directly to the Transmitter using CAT6 / CAT6a / CAT7 cable.

Do not connect the HDBaseT outputs through:

• Network switch 
• Router 
• Internet network 
• LAN switch 
• Standard Ethernet network 
• Home or office data network 

This product is an HDBaseT splitter extender, not an AV-over-IP system.

IMPORTANT — One-Way PoC Is Supported

The UHD18-EXB400-K supports one-way PoC from the Transmitter to the Receivers.

This means the Transmitter can power the HDBaseT Receivers through the CAT cable.

The package includes one 24V DC locking power adapter.

If a Receiver does not power on, check the Transmitter power, CAT cable, cable termination, and HDBaseT connection.

IMPORTANT — HDMI Loop Out Is on the Transmitter

The Transmitter includes HDMI LOOP OUT.

This HDMI loop output can be used to connect a local display near the HDMI source.

Example setup:

The local display and all remote displays show the same HDMI source.

IMPORTANT — Audio De-Embedding Is Supported

The UHD18-EXB400-K supports digital and analog audio de-embedded output on the Transmitter.

Audio output ports include:

Use the audio outputs to send sound to an amplifier, powered speakers, audio receiver, or external audio system.

If analog audio does not work, set the HDMI source audio output to PCM / Stereo.

IMPORTANT — IR Pass-Through Is Supported

The UHD18-EXB400-K supports IR pass-through routed to the HDBaseT outputs.

The package includes:

IR can be used for source control from the Receiver/display side or display control from the Transmitter/source side.

Typical source-control setup:

• Connect IR Receiver cable to IR IN on the HDBaseT Receiver 
• Connect IR Blaster cable to IR OUT on the Transmitter 
• Place the IR Receiver near the remote display 
• Place the IR Blaster near the HDMI source device’s IR window 

IMPORTANT — RS-232 Pass-Through Is Supported

The UHD18-EXB400-K supports RS-232 pass-through between the Transmitter and Receivers.

RS-232 can be used for:

• Projector control 
• Display control 
• Control processor integration 
• Matrix control 
• Automation systems 
• Firmware update 
• Splitter command control 

The Transmitter RS-232 port supports three functions:

Default serial settings:

IMPORTANT — Advanced EDID Management Is Included

The UHD18-EXB400-K includes a 5-pin EDID DIP switch and ASCII command EDID control.

EDID options include:

Use EDID management when there is no video, wrong resolution, audio compatibility issue, or mixed display capability.

IMPORTANT — ASCII Command Control Is Supported

The UHD18-EXB400-K supports ASCII command control through the RS-232 port.

ASCII commands can control or check:

• Power 
• Reboot 
• Factory reset 
• Firmware version 
• Input connection status 
• HDMI loop output status 
• HDBaseT output status 
• HDMI loop stream on / off 
• HDBaseT output stream on / off 
• HDCP setting 
• EDID settings 
• User EDID 
• RS-232 bypass routing 

This is useful for professional AV control systems and troubleshooting.

IMPORTANT — HDMI Audio Format Support

The UHD18-EXB400-K supports HDMI audio pass-through up to 7.1CH HD audio.

Supported HDMI audio formats include:

• LPCM 2.0 / 2.1 / 5.1 / 6.1 / 7.1 
• Dolby Digital 
• Dolby TrueHD 
• Dolby Digital Plus 
• DTS-ES 
• DTS-HD Master Audio 
• DTS-HD HRA 
• DTS:X 

The connected HDMI source, displays, AVR, or audio system must also support the selected audio format.

Ports and Panel Layout

Step-by-Step Setup

1. Connect the HDMI source device to HDMI IN on the Transmitter. 
   Examples include a Blu-ray player, cable box, streaming device, media player, laptop, desktop PC, DVR, NVR, or HDMI matrix output. 
2. Connect a local display to HDMI LOOP OUT on the Transmitter if needed. 
3. Connect HDBT OUTPUT 1 on the Transmitter to HDBT IN on Receiver 1 using CAT6 / CAT6a / CAT7 cable. 
4. Repeat for HDBT OUTPUT 2 through HDBT OUTPUT 8 if using more remote displays. 
5. Connect each Receiver HDMI OUT to its display. 
6. Connect the included DC 24V locking power adapter to the Transmitter. 
7. Turn on the Transmitter using the POWER switch. 
8. If using audio de-embedding, connect COAX or L/R AUDIO OUT to an amplifier, powered speakers, or audio system. 
9. If using IR control, connect IR Receiver and IR Blaster cables in the required control direction. 
10. If using RS-232, connect the Phoenix connector wiring between the control system and the device. 
11. Set the EDID DIP switch based on the required resolution and audio format. 
12. Power on the HDMI source and displays. 
13. Check the POWER, IN, LOOP, OUT, connection, and data signal indicators. 
14. Test video, audio, HDMI loop out, IR, RS-232, and audio output. 

CAT Cable Requirement — Critical

Use high-quality CAT6 / CAT6a / CAT7 cable.

Poor CAT cable may cause:

• No video 
• Flickering 
• Black screen 
• Receiver not powering on 
• Poor connection signal indicator 
• HDBaseT link failure 
• Audio dropouts 
• IR control issues 
• RS-232 issues 
• 4K@60Hz not working 

Use direct CAT cable runs whenever possible.

HDMI Cable Requirement — Critical

Use HDMI cables rated for 18Gbps when using 4K@60Hz 4:4:4.

Poor HDMI cables may cause:

• No picture 
• Flickering 
• Black screen 
• HDR issues 
• Audio dropouts 
• HDCP handshake issues 
• No signal on HDMI loop out 
• No signal on HDBaseT outputs 

For troubleshooting, test the HDMI source directly with the display before using the splitter extender.

Power Requirement — Critical

The UHD18-EXB400-K uses one DC 24V power adapter connected to the Transmitter.

If a Receiver does not power on, check the Transmitter power, CAT cable, and HDBT link.

Understanding the Transmitter

The Transmitter is installed near the HDMI source.

It has:

• HDMI IN 
• HDMI LOOP OUT 
• Eight HDBaseT outputs 
• COAX audio output 
• L/R analog / balanced audio output 
• IR IN and IR OUT 
• RS-232 
• EDID DIP switch 
• DC 24V power input 
• POWER switch 
• POWER, IN, LOOP, and OUT LEDs 

The Transmitter splits the HDMI source and sends it to the local HDMI loop display and up to eight HDBaseT Receivers.

Understanding the HDBaseT Receiver

Each HDBaseT Receiver is installed near a remote HDMI display.

Each Receiver has:

• HDBT IN 
• HDMI OUT 
• AUDIO OUT 
• IR IN and IR OUT 
• RS-232 
• SERVICE port 
• Optional DC 24V input 
• Power, connection, and data signal indicators 

The Receiver receives HDMI over HDBaseT and outputs it to the connected display.

Understanding HDMI Loop Out

The HDMI LOOP OUT port on the Transmitter lets you connect a local display near the source.

The local display and all remote HDBaseT displays show the same HDMI source.

This is useful for AV racks, control rooms, sports bars, classrooms, and commercial installations where a local preview display is needed.

Understanding Audio De-Embedding

Audio de-embedding allows the Transmitter to output audio separately from the HDMI signal.

If audio does not work from the L/R output, set the HDMI source to PCM / Stereo.

Understanding IR Pass-Through

IR pass-through allows remote control signals to travel between the Transmitter and Receivers.

Use the IR Receiver cable where the remote control will be pointed.

Use the IR Blaster cable near the device being controlled.

IR remote working distance is listed as:

Do not swap IR Receiver and IR Blaster cables because their pin definitions are different.

Understanding RS-232 Pass-Through

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

The Transmitter RS-232 can also be used for ASCII command control of the splitter.

Common RS-232 uses include:

• Display control 
• Projector control 
• Control processor integration 
• Firmware update 
• EDID control 
• Output stream control 
• RS-232 routing to HDBaseT outputs 

Understanding Signal Indicators

Use these indicators to troubleshoot CAT cable, HDBaseT link, HDCP, and HDMI input issues.

Supported Video and Audio

The UHD18-EXB400-K supports video formats including:

Supported HDMI audio formats include:

Supported de-embedded audio:

Supported Technical Specifications

What Source Devices Is the UHD18-EXB400-K Compatible With?

The UHD18-EXB400-K is compatible with HDMI source devices such as:

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

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

What Displays Is the UHD18-EXB400-K Compatible With?

The UHD18-EXB400-K can connect to HDMI displays such as:

• 4K TVs 
• 1080p TVs 
• Projectors 
• Monitors 
• Commercial displays 
• Digital signage screens 
• Classroom displays 
• Conference room displays 
• Church displays 
• Restaurant TVs 
• Bar displays 
• Retail displays 
• Local display near the source 

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

What Audio Devices Is the UHD18-EXB400-K Compatible With?

The audio outputs can connect to:

• Amplifiers 
• AV receivers 
• Powered speakers 
• Audio processors 
• Distributed audio systems 
• Classroom audio systems 
• Conference room audio systems 

Use COAX output for digital audio and L/R output for analog stereo audio.

Frequently Asked Questions

Q: What is the OREI UHD18-EXB400-K used for? 
A: The UHD18-EXB400-K is used to split and extend one HDMI source to up to eight remote HDMI displays over CAT6 / CAT6a / CAT7 cable using HDBaseT technology.

Q: Is the UHD18-EXB400-K a splitter or extender? 
A: It is both. It is a 1x8 HDMI HDBaseT splitter extender.

Q: How many HDMI inputs does it have? 
A: It has one HDMI input.

Q: How many HDBaseT outputs does it have? 
A: It has eight HDBaseT outputs.

Q: How many Receivers are included? 
A: Eight HDBaseT Receivers are included.

Q: Does it support a local display? 
A: Yes. The Transmitter has HDMI LOOP OUT for a local display.

Q: Does the UHD18-EXB400-K support 4K@60Hz? 
A: Yes. It supports up to 4K@60Hz 4:4:4.

Q: Does it support 8K? 
A: No. It supports up to 4K@60Hz.

Q: Does it support 4K@120Hz? 
A: No. It does not support 4K@120Hz.

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

Q: What HDCP version does it support? 
A: It supports HDCP 2.2 and HDCP 1.x.

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

Q: Does it support HDR? 
A: Yes. It supports HDR, HDR10+, HLG, and Dolby Vision.

Q: How far can it extend 4K@60Hz? 
A: It extends 4K@60Hz up to 120m / 394ft over CAT6 / CAT6a / CAT7 cable.

Q: How far can it extend 1080p@60Hz? 
A: It extends 1080p@60Hz up to 150m / 492ft over CAT6 / CAT6a / CAT7 cable.

Q: Can I connect the HDBaseT outputs through a network switch? 
A: No. The HDBaseT outputs should connect directly to the included Receivers.

Q: Is this AV over IP? 
A: No. This is an HDBaseT splitter extender, not an AV-over-IP system.

Q: Does it support PoC? 
A: Yes. It supports one-way PoC from the Transmitter to the Receivers.

Q: Do the Receivers need separate power adapters? 
A: Normally no. The Receivers can be powered by the Transmitter through the CAT cable.

Q: Does it support audio extraction? 
A: Yes. It supports coaxial and analog L/R audio de-embedded output.

Q: What audio formats are supported through HDMI? 
A: It supports LPCM up to 7.1, Dolby Digital, Dolby TrueHD, Dolby Digital Plus, DTS-ES, DTS-HD Master Audio, DTS-HD HRA, and DTS:X.

Q: What audio formats are supported from the coaxial output? 
A: Coaxial output supports PCM 2.0, Dolby Digital / Plus, and DTS 2.0 / 5.1.

Q: What audio format is supported from analog L/R output? 
A: Analog L/R output supports PCM 2.0CH.

Q: Does it support IR control? 
A: Yes. IR pass-through is supported.

Q: Does it support RS-232? 
A: Yes. RS-232 command control and RS-232 pass-through are supported.

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

Q: Does it support EDID management? 
A: Yes. It supports EDID through DIP switch settings and ASCII commands.

Q: Can it copy EDID from the local loop display? 
A: Yes. It can copy EDID from HDMI LOOP OUT.

Q: Can it copy EDID from HDBaseT outputs? 
A: Yes. It can copy EDID from HDBaseT outputs.

Q: Does it create extended desktop across eight displays? 
A: No. It duplicates one HDMI source to the connected displays.

Q: What should I do if there is no video? 
A: Check the power adapter, HDMI source, HDMI cables, CAT cable, EDID setting, HDBaseT output connection, and the connection/data signal indicators.

Q: What should I do if the connection indicator is flashing? 
A: The Transmitter and Receiver are in poor connection status. Check CAT cable quality, terminations, cable length, and direct connection.

Q: What should I do if the connection indicator is dark? 
A: The Transmitter and Receiver are not connected. Check the CAT cable and confirm HDBT OUT is connected to HDBT IN.

Q: What should I do if the data signal indicator is dark? 
A: There is no HDMI signal. Check the HDMI source, HDMI cable, and source output setting.

Q: What should I do if 4K@60Hz does not work? 
A: Use 18Gbps HDMI cables, high-quality CAT6 / CAT6a / CAT7 cable, keep the run within 120m / 394ft, confirm the source and display support 4K@60Hz, and choose a compatible EDID setting.

Q: What should I do if analog audio output does not work? 
A: Set the HDMI source audio output to PCM / Stereo and connect the L/R output to an amplifier or speaker.

Q: What should I do if IR control does not work? 
A: Confirm the IR Receiver and IR Blaster cables are connected in the correct direction and that the IR Blaster is placed near the controlled device’s IR sensor.

Q: What should I do if RS-232 does not work? 
A: Check Phoenix connector wiring, baud rate, RS-232 routing, and control command format.

Q: Does the UHD18-EXB400-K need external power? 
A: Yes. Connect the included DC power adapter to the Transmitter. The Receivers are powered through the CAT cables by PoC.