HKM-404 Overview and Use Cases

What Is the HKM-404?

The OREI HKM-404 is a USB 2.0 4x4 Matrix Switch designed to allow four computers to share four USB devices.

It lets multiple computers access shared USB peripherals such as keyboards, mice, printers, USB flash drives, webcams, external hard drives, scanners, and other compatible USB devices without constantly unplugging and reconnecting cables.

The HKM-404 has four USB Host ports for connecting up to four computers and four USB Device ports for connecting up to four USB peripherals. It supports USB 2.0 / USB 1.1 compatibility and manual switching using the front-panel PC buttons or the included desktop remote.

The HKM-404 is useful for office desks, conference rooms, security monitoring centers, control rooms, IT management environments, workstations, and shared computer setups where multiple computers need access to the same USB devices.

IMPORTANT — HKM-404 Is a USB Matrix, Not a Video Matrix

The HKM-404 switches USB devices between computers.

This product does not switch HDMI, DisplayPort, VGA, or video signals.

It is for USB device sharing only.

IMPORTANT — Four Computers Can Share Four USB Devices

The HKM-404 supports a 4x4 USB matrix configuration.

Each connected computer can access the USB devices based on the selected routing.

This reduces cable swapping and helps centralize USB peripherals in multi-computer workspaces.

IMPORTANT — One USB Device Connects to One Host at a Time

A single USB device cannot be actively used by multiple computers at the exact same time.

The matrix allows switching, not simultaneous sharing.

Before switching a USB storage device, safely eject it from the current computer to avoid file corruption.

IMPORTANT — USB 2.0 and USB 1.1 Compatibility

The HKM-404 supports USB 2.0 and USB 1.1 devices.

This product is a USB 2.0 matrix. USB 3.0 devices may work at USB 2.0 behavior if backward compatible, but USB 3.0 speed is not listed.

IMPORTANT — No Driver Installation Required

The HKM-404 is plug-and-play.

No software driver is required for normal operation.

IMPORTANT — Two Switching Methods Are Supported

The HKM-404 can be controlled manually using either the front-panel buttons or the included desktop remote.

Use the PC1, PC2, PC3, or PC4 button to choose which computer is accessing the connected USB device.

The desktop remote connects to the KEY remote input port.

IMPORTANT — External Power Port Is Available

The HKM-404 includes a USB-C 5V/1A power input.

The manual notes the DC 5V/1A power adapter is not included.

For standard keyboard and mouse use, power from the connected USB host computers may be enough.

For power-hungry USB devices such as external hard drives, webcams, scanners, or multiple USB devices, connect a 5V/1A or higher USB power supply to the USB-C power port.

IMPORTANT — USB Hubs Can Be Used, But Bandwidth and Power Are Shared

USB hubs may be connected to the HKM-404 device ports.

If a USB hub is used, the total USB bandwidth and available power are shared across connected devices.

For best performance, use powered USB hubs when connecting multiple or high-power peripherals.

Ports and Panel Layout

Understanding the LED Indicators

Use the LEDs to confirm which USB device connection is currently active.

Step-by-Step Setup

1. Place the HKM-404 near the computers and USB devices.
2. Connect PC1 to USB HOST 1 using one of the included USB cables.
3. Connect PC2 to USB HOST 2 if needed.
4. Connect PC3 to USB HOST 3 if needed.
5. Connect PC4 to USB HOST 4 if needed.
6. Connect USB peripherals to USB DEVICE 1–4.

Examples include keyboard, mouse, printer, scanner, webcam, USB flash drive, or external hard drive.

1. Connect the desktop remote to the KEY / remote input port if you want remote switching control.
2. If using high-power USB devices, connect a 5V/1A or higher USB power adapter to the USB-C power input.
3. Power on the connected computers.
4. Press PC1, PC2, PC3, or PC4 to choose the computer that should access the USB devices.
5. Check the LED indicators to confirm device access.
6. Test keyboard, mouse, printer, webcam, scanner, USB storage, or other connected USB devices.

USB Cable Requirement — Critical

Use good-quality USB cables between the computers and the HKM-404.

Poor USB cables may cause:

• USB device not detected
• Keyboard or mouse lag
• Printer not responding
• Webcam not working
• USB storage disconnecting
• Switching failure
• Device reconnect delays

For troubleshooting, test the USB device directly with the computer first.

USB Device Requirement — Critical

The HKM-404 works best with compatible USB 2.0 / USB 1.1 devices.

Compatible USB devices include:

• Keyboard
• Mouse
• Printer
• Scanner
• Webcam
• USB flash drive
• External hard drive
• USB hub
• Other compatible USB peripherals

Some high-power USB devices may require external power.

If a USB device does not work, connect a USB-C 5V/1A or higher power supply to the HKM-404 power port.

Power Requirement — Critical

The HKM-404 includes a USB-C power input for additional USB device power.

If USB devices are not detected, disconnect randomly, or do not mount correctly, use external power.

The manual recommends using a 5V/1A or 2A adapter if your USB devices require higher power consumption.

USB Storage Requirement — Critical

When using USB flash drives or external hard drives, safely eject the USB storage device before switching hosts.

If a USB storage device does not mount:

• Safely eject the USB device before switching hosts.
• Try a different USB port on the matrix.
• Wait a few seconds after switching for the computer to recognize the device.
• Connect external power to the HKM-404 if the storage device requires more power.
• Test the storage device directly with the computer.

Switching storage devices without ejecting may cause data loss or file corruption.

Understanding the Application Example

The application diagram shows four computers connected to the HKM-404 using USB cables. On the device side, USB peripherals such as a printer, keyboard, mouse, USB flash drive, and scanner connect to the USB DEVICE ports.

This shows the main use case: multiple computers can share one group of USB peripherals, and the user can switch access between computers using the front buttons or desktop remote.

Supported Technical Specifications

Package Contents

What Computers Is the HKM-404 Compatible With?

The HKM-404 can connect to computers such as:

• Windows PCs
• macOS computers
• Linux computers
• Desktop computers
• Laptops
• Workstations
• Mini PCs
• Control-room PCs
• IT management computers

Each computer connects to one of the USB HOST ports.

What USB Devices Is the HKM-404 Compatible With?

The HKM-404 can share USB devices such as:

• USB keyboard
• USB mouse
• Printer
• Scanner
• Webcam
• USB flash drive
• External hard drive
• USB hub
• Other USB 2.0 / USB 1.1 compatible peripherals

Device behavior depends on USB compatibility, driver support on the computer, power requirements, and bandwidth needs.

Frequently Asked Questions

Q: What is the HKM-404 used for? 
A: It is used to let up to four computers share up to four USB devices.

Q: Is the HKM-404 a USB matrix switch? 
A: Yes. It is a USB 2.0 4x4 Matrix Switch.

Q: Does it switch HDMI video? 
A: No. It only switches USB devices. It does not switch HDMI, DisplayPort, VGA, or video signals.

Q: How many computers can connect to it? 
A: Up to four computers can connect to the USB HOST ports.

Q: How many USB devices can connect to it? 
A: Up to four USB devices can connect to the USB DEVICE ports.

Q: Can multiple computers access the same USB device at the same time? 
A: No. A single USB device can only be connected to one host computer at a time.

Q: Does the HKM-404 support USB 2.0? 
A: Yes. It supports USB 2.0.

Q: Does it support USB 1.1? 
A: Yes. It supports USB 1.1 compatibility.

Q: Does it support USB 3.0 speed? 
A: USB 3.0 speed is not listed. This is a USB 2.0 matrix.

Q: Does it require drivers? 
A: No. It is plug-and-play and does not require driver installation.

Q: Which operating systems are supported? 
A: The manual lists compatibility with Windows, Linux, macOS, and other operating systems.

Q: Can I connect a keyboard and mouse? 
A: Yes. USB keyboards and mice are supported.

Q: Can I connect a printer or scanner? 
A: Yes. Printers and scanners are supported.

Q: Can I connect a webcam? 
A: Yes. Webcams are supported.

Q: Can I connect a USB flash drive or external hard drive? 
A: Yes, but safely eject the storage device before switching hosts.

Q: Can I use USB hubs with the matrix? 
A: Yes. USB hubs can be connected to the device ports, but total bandwidth and power are shared across connected devices.

Q: How do I switch between computers? 
A: Press the PC1, PC2, PC3, or PC4 button on the device, or use the included desktop remote.

Q: Does it include a desktop remote? 
A: Yes. The package includes desktop remotes.

Q: What does the KEY / remote input do? 
A: It connects the included desktop remote for switching control.

Q: Does it need external power? 
A: It can work from USB host power for basic devices, but external USB-C 5V/1A power is recommended for power-hungry USB devices.

Q: Is the power adapter included? 
A: No. The manual states the DC 5V/1A adapter is not included.

Q: What power supply should I use? 
A: Use a USB-C 5V/1A minimum power supply. A 5V/2A adapter may be better for higher-power USB devices.

Q: What should I do if a USB device is not detected? 
A: Confirm the USB device is routed to the correct host, reconnect the USB cable, and test the device directly with the host computer.

Q: What should I do if a USB storage device does not mount after switching? 
A: Safely eject the USB storage device before switching hosts, try a different USB port, wait a few seconds after switching, and connect external power if needed.

Q: Why does my USB device disconnect or fail after switching? 
A: The device may require more power, the USB cable may be weak, or the computer may need a few seconds to recognize the device after switching.

Q: What do the LED indicators show? 
A: The LEDs indicate which USB device is being accessed by the selected PC.

Q: What is included in the package? 
A: The package includes the HKM-404 Matrix, four USB cables, four desktop remotes, and one user manual.

Q: What are the dimensions of the HKM-404? 
A: 100mm x 89mm x 20mm / 3.93in x 3.50in x 0.79in.