X4UH-KVM-ERX Overview and Use Cases – OREI

What Is the X4UH-KVM-ERX?

The OREI X4UH-KVM-ERX is the Decoder unit of the ToVi X4 system — an HDMI extender and AV-over-IP solution designed for high-performance, long-distance signal reception. Fully compliant with HDCP 2.2 and HDMI 2.0b, it receives and outputs video up to 4K@60Hz (4:4:4) with 18Gbps bandwidth.

The ERX (Decoder) connects to your display and receives video, audio, IR, RS-232, and USB signals transmitted over a CAT5E/6/6A/7 network cable or optical fiber from an X4UH-KVM-ETX Encoder unit, up to 100 meters (328 feet) away.

It supports ARC/eARC and S/PDIF audio return to send display audio back to the source, includes two relay channels and two I/O ports for contact control, and allows output scaling to match the connected display. The ERX operates on a 1G Ethernet network with PoE support and can be managed through a built-in web interface, Telnet, or SSH.

IMPORTANT — The X4UH-KVM-ERX Is the Decoder (Receiver), Not the Transmitter

The X4UH-KVM-ERX is the display-side unit. It connects to your TV, monitor, or projector and receives the signal from the Encoder.

To send the signal, you need the X4UH-KVM-ETX (Encoder). The ETX and ERX must be used together to form a complete system.

IMPORTANT — Requires a Compatible 1G Network Switch for Multi-Unit Deployments

When using multiple encoders and decoders on the same network, a layer 3 managed gigabit switch with IGMP snooping and 8KB jumbo frame support is required. Recommended switch models include the Cisco SG500, Cisco Catalyst series, Huawei S5720S-28X-PWR-LI-AC, ZyXEL GS2210, and Luxul AMS-4424P.

For a point-to-point single connection, a switch is not required — you can connect the ERX and ETX directly.

IMPORTANT — Audio Return Requires Matching Settings on Both the ETX and ERX

For ARC/eARC or S/PDIF audio return to work, both the X4UH-KVM-ETX (Encoder) and the X4UH-KVM-ERX (Decoder) must be set to the same audio return mode. In unicast mode, this can be set via the front panel buttons on each unit. In multicast mode, it must be set via the Controller Box or API commands.

For ARC use, connect an ARC-compatible audio amplifier to the Encoder's HDMI IN and an ARC TV to the Decoder's HDMI OUT. For eARC, both the amplifier and the TV must support eARC.

Ports and Panel Layout

Port / LED / Button	Location	Function
RESET	Front panel	Press and hold after powering on until the POWER LED and LINK LED flash simultaneously, then release to reset the device to factory settings.
POWER LED (Red)	Front panel	Light on: System is powered on (POE or DC power supply). Light off: System is powered off.
LINK LED (Green)	Front panel	Light on: Decoder is connected to the Encoder and video signal is being received. Light flashes: Connected but no video signal. Light off: Not connected.
LED Screen	Front panel	Displays the selected Encoder ID by default. Shows configuration options during setup.
CH SELECT (UP/DOWN)	Front panel	Used to select the Encoder channel to connect to and to set other configuration options.
USB 1.1 DEVICE (x2)	Front panel	Connect USB 1.1 devices such as a keyboard or mouse.
USB 2.0 DEVICE (x2)	Front panel	Connect USB 2.0 devices such as a USB flash drive or USB camera.
IR OUT	Rear panel	IR signal output port. IR level can be set to 5V or 12V (default) via panel buttons.
IR IN	Rear panel	IR signal input port. IR level can be set to 5V or 12V (default) via panel buttons.
RELAYS / DIGITAL IO	Rear panel	2-channel relay ports and 2-channel GPIO ports for contact control. VCC output is 12V or 5V configurable.
RS-232	Rear panel	RS-232 serial port supporting command pass-through and local serial port control.
AUDIO IN	Rear panel	Analog audio input. Audio can be transmitted to the Encoder's AUDIO OUT in unicast (point-to-point) mode.
AUDIO OUT	Rear panel	Analog audio output. Outputs the same audio as the HDMI OUT when the audio format is LPCM.
SPDIF IN	Rear panel	S/PDIF optical audio input port.
HDMI OUT	Rear panel	HDMI signal output port. Connect to an HDMI display such as a TV or monitor.
FIBER	Rear panel	Connect an optical fiber module to receive signals directly from the Encoder or through a switch.
LAN (POE)	Rear panel	1G LAN port. Connect to a network switch. When the switch provides POE, the DC 12V adapter is not needed.
Data Signal Indicator (Yellow)	Rear panel	Flashing: Data is being transmitted. Off: Network cable is not properly connected.
Link Signal Indicator (Green)	Rear panel	On: Network cable is connected normally. Off: Network cable is not properly connected.
DC 12V	Rear panel	Power the device via DC 12V/2.5A adapter or via POE from the network switch.

Step-by-Step Setup

Connect your display (TV, monitor, or projector) to the HDMI OUT port on the X4UH-KVM-ERX.
Connect the LAN (POE) port on the ERX to your 1G network switch using a CAT5E/6/6A/7 cable, or connect directly to the ETX Encoder for a point-to-point setup.
Alternatively, connect the FIBER port if using optical fiber cabling.
Power the ERX via the included DC 12V/2.5A adapter, or use a PoE-capable network switch (no DC adapter needed if PoE is supplied).
After powering on, use the CH SELECT (UP/DOWN) buttons on the front panel to select the Encoder ID you want to connect to (matching the ETX unit's ID). The LED screen displays the currently selected ID (000 by default).
Connect USB devices (keyboard, mouse, flash drive, USB camera) to the USB 1.1 or USB 2.0 DEVICE ports as needed for KVM operation.
If using audio return, connect a S/PDIF audio source to the SPDIF IN port, or rely on ARC/eARC via the HDMI OUT port on the ERX.
Enable ARC/eARC on the connected display if you are using audio return.
Use the CH SELECT buttons to configure output scaling, IR mode, audio return type, IP mode, Fiber/Copper mode, unicast/multicast mode, and audio return mode as needed. Press and hold UP + DOWN for 5 seconds to enter configuration mode.
Confirm the LINK LED is solid green, indicating a successful connection with the Encoder and active video signal reception.
For advanced system control, connect the ERX to the network managed by the X4UH-CB Controller Box, or access the built-in web interface via the device's IP address.

Cable Requirement

For network transmission, use CAT5E, CAT6, CAT6A, or CAT7 cables. Maximum transmission distance is 100 meters (328 feet). For HDMI connections to your display, use Premium High Speed HDMI cables. Recommended maximum HDMI cable lengths: 16ft/5m at 4K60, 32ft/10m at 4K30, and 50ft/15m at 1080p60.

Front Panel Configuration (CH SELECT Buttons)

The CH SELECT UP and DOWN buttons on the front panel allow you to configure the ERX without a computer. When powered on, simply press UP/DOWN to select which Encoder ID to connect to. To enter configuration mode, press and hold UP + DOWN together for 5 seconds until the LED screen shows "CFN". Then use UP/DOWN to navigate pages and press and hold UP + DOWN for 5 seconds on any page to enter and confirm settings.

Available configuration pages on the ERX:

Page 1 — Device ID: Set the Decoder's own device ID (000–762). Default is 000.
Page 2 — Output Scaling: Choose from S00 (bypass) through S13. Options include 1080p50, 1080p60, 720p50, 720p60, 2160p24/30/50/60, and various PC resolutions up to 1920x1200.
Page 3 — IR Mode: Select IR1 (5V) or IR2 (12V, default).
Page 4 — Audio Return Type: Select ARC (eARC/ARC return via HDMI OUT, default) or SPD (S/PDIF return via SPDIF IN).
Page 5 — IP Mode: Select IP1 (static, default 169.254.100.253), IP2 (DHCP), or IP3 (auto IP, default).
Page 6 — Fiber/Copper Mode: Select CPP (copper, default) or FIB (fiber).
Page 7 — Multicast Mode: Select CA1 (unicast, default) or CA2 (multicast).
Page 8 — Audio Return Mode: Select C2C (eARC/ARC or S/PDIF return, default) or A2A (analog audio return, unicast only).

To exit any setting page quickly, hold down the DOWN button. The menu also auto-exits after 5 seconds of inactivity.

What Displays Is the X4UH-KVM-ERX Compatible With?

The X4UH-KVM-ERX is compatible with any HDMI display, including TVs, monitors, and projectors. It supports displays with or without ARC/eARC. The ERX's output scaling feature (S00–S13) allows you to match the output resolution to your display's native resolution.

For audio return, the connected display must support ARC or eARC depending on the mode you configure.

Frequently Asked Questions

Q: What does the X4UH-KVM-ERX do?

A: The X4UH-KVM-ERX is the Decoder (receiver) in the ToVi X4 system. It receives the video and audio signal transmitted by the X4UH-KVM-ETX Encoder over a network cable or optical fiber and outputs it to a connected display.

Q: Can the X4UH-KVM-ERX work without the X4UH-KVM-ETX Encoder?

A: No. The X4UH-KVM-ERX requires a paired X4UH-KVM-ETX, X4UH-UC-ETX, or X4UH-WUC-ETX Encoder to receive a signal. They must be connected on the same network.

Q: How do I connect the X4UH-KVM-ERX to the correct Encoder?

A: Use the CH SELECT (UP/DOWN) buttons to select the Encoder ID that matches the ETX unit you want to receive from. The LED screen on the ERX shows the currently selected ID. Otherwise, the best way for routing management is using the WebGUI on the X4UH-CB control box.

Q: Can I connect a keyboard and mouse to the ERX?

A: Yes. The ERX has two USB 1.1 DEVICE ports (ideal for keyboard and mouse) and two USB 2.0 DEVICE ports (for flash drives, cameras, etc.), enabling KVM operation at the display end.

Q: Does the ERX support 4K output?

A: Yes. The ERX outputs up to 4K@60Hz (4:4:4), matching the signal received from the ETX Encoder.

Q: Can I scale the output resolution on the ERX?

A: Yes. The ERX supports output scaling through the front panel configuration (Page 2). Options range from bypass (S00) to 4K60 (S08) and various PC resolutions.

Q: Can the ERX send audio back from the TV to the source?

A: Yes. The ERX supports ARC/eARC audio return via the HDMI OUT port and S/PDIF audio return via the SPDIF IN port. Both the ERX and the ETX must be set to the same audio return mode for this to work.

Q: Can I power the ERX without the DC adapter?

A: Yes. If your network switch supports PoE, the ERX can be powered directly over the network cable. The DC 12V adapter is not needed in that case.

Q: How do I check the IP address of the ERX?

A: Press and hold the UP button for 5 seconds. The LED screen will display the IP mode followed by the four octets of the IP address in sequence.

Q: What is the default IP mode?

A: The default is IP3 (Auto IP mode), with a network segment of 169.254.xxx.xxx. The default static IP (IP1) is 169.254.100.253.

Q: Can I use the ERX in a video wall setup?

A: Yes. Multiple ERX Decoders can be used together to create video wall configurations up to 9x9. Video wall class management is handled through the X4UH-CB Controller Box or the built-in web interface.

Q: Can the ERX be rack mounted?

A: Yes. The ERX includes mounting ears for installation in a 6U V2 rack (vertically, up to 10 units) or a 1U V2 rack (horizontally, two units side by side).