HDS-402MV Overview and Use Cases

What Is the HDS-402MV?

The OREI HDS-402MV is a seamless 4K@30Hz HDMI matrix multiviewer switch with 4 HDMI inputs and 2 HDMI outputs. It allows up to four HDMI source devices to be routed to two displays, while also supporting multiview layouts on one output.

The HDS-402MV can work as a standard 4-input, 2-output HDMI matrix switch, where Output A and Output B can each show a selected HDMI source. It can also work as a multiviewer, allowing multiple HDMI sources to appear on one screen in layouts such as 2x2, left/right, up/down, one-big-three-small, and PIP.

The HDS-402MV supports HDMI 1.4 and HDCP 1.4, with a video bandwidth of 10.2Gbps. It supports video resolutions up to 4K@30Hz, seamless switching, multiview functionality, built-in scaling, aspect ratio control, PIP, stereo audio output, Toslink digital audio output, front-panel control, IR remote control, RS-232 control, and Micro USB control / firmware update. 

The HDS-402MV is useful for security monitoring, multimedia setups, control rooms, classrooms, conference rooms, retail displays, sports bars, and any setup where multiple HDMI sources need to be viewed or switched across one or two displays.

IMPORTANT — HDS-402MV Is a Matrix and Multiviewer

The HDS-402MV is not just a basic HDMI switch.

It supports two main functions:

This means the product can be used for regular HDMI switching or for viewing multiple sources at the same time.

IMPORTANT — HDS-402MV Supports 4K@30Hz, Not 4K@60Hz or 8K

The HDS-402MV supports video resolutions up to 4K@30Hz.

It does not support 4K@60Hz, 4K@120Hz, or 8K.

For 4K@60Hz systems, use an HDMI 2.0 multiviewer or matrix.

For 8K or 4K@120Hz systems, use an HDMI 2.1 device that supports the required resolution and bandwidth.

IMPORTANT — Multiview Mode Is Not the Same as a Video Wall

The HDS-402MV is a multiviewer, not a video wall controller.

Multiview mode combines multiple HDMI sources onto one display.

It does not split one image across multiple displays to create one large video wall.

Use this product when you want to view multiple HDMI sources on one screen.

Do not use this product if you need a 2x2 video wall where four TVs act like one large display.

IMPORTANT — Output A and Output B Can Be Switched Separately

The HDS-402MV has two HDMI outputs:

• Output A 
• Output B 

Each output can select HDMI Input 1, 2, 3, or 4.

For example:

• Output A can show Input 1 
• Output B can show Input 3 

This makes it useful when two displays need to show different HDMI sources.

IMPORTANT — Multiview Layouts Are Controlled Using MODE, MODIFY, and PIP

The HDS-402MV supports multiple multiview layouts.

The MODE button cycles through different multiview display modes.

The MODIFY button changes which HDMI input appears in each window.

The PIP button is used for Picture-in-Picture mode and also cycles the PIP window position.

The user must select the correct mode first, then use the modify command or remote button combinations to adjust the source layout.

IMPORTANT — Audio Output Has Format Limits

The HDS-402MV includes:

• 3.5mm stereo audio output 
• Toslink / S/PDIF digital audio output 

The manual lists supported audio formats as LPCM, AC3, and DTS.

The remote also allows audio source selection and switching between 2.1CH and 5.1CH mode.

If using the stereo analog output, set the source to a compatible stereo audio format such as PCM / LPCM.

If using Toslink, make sure the connected audio device supports the selected audio format.

IMPORTANT — Micro USB Can Be Used for Firmware Update and Control

The Micro USB port is used for firmware updates and can also be used for configuration and control from third-party control terminals.

The manual notes that the Micro USB port can be used as an RS-232 control port.

It supports Windows 8.1 / 10 / 11 and macOS 10.10 or above.

The Micro USB control baud rate is 115200.

Ports and Panel Layout

Step-by-Step Setup

1. Connect the included 5V/2A power adapter to the DC 5V port on the HDS-402MV. 
2. Connect your HDMI source devices to HDMI Input 1, Input 2, Input 3, and Input 4. 
   Examples include a PC, laptop, DVR, camera system, media player, streaming device, Blu-ray player, DVD player, or cable box. 
3. Connect HDMI Output A and HDMI Output B to your TVs, monitors, projectors, or commercial displays. 
4. If using external audio, connect your audio system to either: 
   • Stereo 3.5mm output 
   • Toslink / S/PDIF output 
5. Turn on the source devices, displays, audio system, and HDS-402MV. 
6. Use the Output A or Output B buttons to select which HDMI input appears on each output. 
7. To use multiview mode, press MODE to cycle through the available layouts. 
8. Use MODIFY and the number buttons to choose which HDMI inputs appear in each multiview window. 
9. Use SCALER to select the output resolution. 
10. Use AUDIO to choose which HDMI input audio is played. 
11. If using RS-232 control, connect through the RS-232 control method or Micro USB control port. 

HDMI Cable Requirement — Critical

For best performance, use high-quality HDMI cables.

The manual troubleshooting section lists the following cable guidance:

Poor-quality or longer HDMI cables may cause:

• No picture 
• Black screen 
• Signal light off 
• Screen splash 
• Pink screen 
• Signal dropouts 
• Multiview display issues 
• 4K@30Hz not working properly 

For troubleshooting, replace the HDMI cable, use shorter HDMI cables, and confirm that the input and output connections are correct.

Understanding Matrix / Seamless Switch Mode

In normal matrix mode, Output A and Output B can each select one HDMI input.

Example:

Use this mode when each display should show one full-screen HDMI source.

Understanding Multiview Modes

The HDS-402MV supports 5 main multiview modes.

Use multiview mode when several sources need to be monitored on one screen.

Understanding 2x2 Four Equal Picture Mode

In 2x2 mode, all four HDMI inputs are displayed on one screen.

Default layout:

Using MODIFY + number keys, the layout can be changed into different input arrangements.

This mode is useful for viewing four camera feeds, computers, media players, or monitoring sources at the same time.

Understanding Left / Right Picture Mode

Left / Right mode shows two HDMI sources side by side.

Default layout:

Use MODIFY + number key combinations to choose which input appears on the left side and which input appears on the right side.

This is useful for comparing two sources or monitoring two devices at once.

Understanding Up / Down Picture Mode

Up / Down mode shows two HDMI sources stacked vertically.

Default layout:

Use MODIFY + number key combinations to select the top and bottom input sources.

This is useful when two sources need to be viewed at the same time in a vertical split-screen layout.

Understanding One Big Three Small Mode

One Big Three Small mode shows one HDMI input as the larger image and the other inputs as smaller images.

Default layout:

Use MODIFY + number keys to choose which input becomes the large window.

This is useful when one main source needs priority while the other sources remain visible.

Understanding PIP Mode

PIP stands for Picture-in-Picture.

In PIP mode, one HDMI input appears as the main image and another HDMI input appears as a smaller window.

Default layout:

Use PIP + MODIFY + number key combinations to choose the main input and small input.

Press the PIP button to cycle the small window location.

The PIP window can move between the corners of the screen.

Understanding Output Resolution Scaling

The HDS-402MV includes built-in scaling.

The SCALER button switches the HDMI output resolution between:

Use 4K@30Hz when the connected display supports 4K@30Hz.

Use 1080p for older displays or troubleshooting.

Use scaler control if the display does not show video or if the selected resolution is not compatible.

Understanding Aspect Ratio Control

The HDS-402MV supports aspect ratio control.

The Full Screen button switches between:

• Full-screen mode 
• Original video ratio 

Use this when the multiview image appears stretched or when the user wants to preserve the original source aspect ratio.

Understanding Audio Selection

The HDS-402MV allows the user to choose which source audio is played.

The Audio button can select the audio source.

Long pressing the Audio button switches between:

• 2.1CH mode 
• 5.1CH mode 

Audio output options include:

If using stereo output, use a stereo-compatible audio format.

If using Toslink, make sure the connected audio device supports LPCM, AC3, or DTS as needed.

Understanding RS-232 Control

The HDS-402MV supports RS-232 control.

Default RS-232 settings:

Important RS-232 notes:

• A carriage return is required at the end of each command string. 
• Commands are not case-sensitive. 
• Spaces shown in the manual are for clarity; commands should not include spaces. 
• The response ends with carriage return followed by line feed. 

RS-232 commands can control:

• Power on / off 
• Output source selection 
• Output on / off 
• 2x2 mode 
• Left / right picture mode 
• Up / down picture mode 
• One big three small mode 
• PIP mode 
• PIP window position 
• Output resolution scaling 
• Aspect ratio 
• External Optical and analog audio output 
• 2.1CH / 5.1CH audio mode 
• Audio input channel selection 
• OSD display 
• Front-panel button enable / disable 
• RS-232 baud rate 
• Factory reset 

Understanding Micro USB Control

The Micro USB port can be used for configuration and control from third-party control terminals.

It can also be used for firmware updates.

The manual notes:

If the computer operating system is too old, the CDC driver may need to be installed manually.

Understanding Power-Off Memory

The HDS-402MV includes power-off memory.

This means the device retains the last setup after restart.

If the product is powered off and turned back on, it can restore the previous configuration instead of requiring the user to set the layout again.

What Source Devices Is the HDS-402MV Compatible With?

The OREI HDS-402MV is compatible with HDMI source devices such as:

• PCs 
• Laptops with HDMI output 
• DVRs 
• Camera systems 
• Blu-ray players 
• DVD players 
• Streaming devices 
• Cable boxes 
• Satellite receivers 
• Set-top boxes 
• Media players 
• Game consoles with supported HDMI output 

For 4K@30Hz, the source device, HDMI cable, and display must all support 4K@30Hz.

What Displays Is the HDS-402MV Compatible With?

The HDS-402MV can connect to HDMI displays such as:

• TVs 
• Monitors 
• Projectors 
• Commercial displays 
• Security monitoring displays 
• Conference room displays 
• Classroom displays 
• Retail displays 

For 4K@30Hz output, the connected display must support 4K@30Hz over HDMI.

What Audio Devices Is the HDS-402MV Compatible With?

The HDS-402MV can send audio to:

• Toslink soundbars 
• AV receivers 
• Amplifiers 
• Powered speakers 
• Stereo speaker systems 
• HDMI TVs or HDMI audio systems 

Use Toslink for digital audio systems.

Use the 3.5mm stereo output for analog stereo audio systems.

Make sure the connected audio device supports the selected audio format.

Frequently Asked Questions

Q: What is the OREI HDS-402MV used for? 
A: The HDS-402MV is used to connect up to four HDMI source devices to two HDMI displays. It can work as a seamless matrix switcher or as a multiviewer that shows multiple HDMI sources on one screen.

Q: Is the HDS-402MV a matrix switch? 
A: Yes. It is a 4-input, 2-output HDMI matrix switch with multiviewer functionality.

Q: Is the HDS-402MV a multiviewer? 
A: Yes. It supports multiview layouts including 2x2, left/right, up/down, one-big-three-small, and PIP.

Q: Is the HDS-402MV a video wall controller? 
A: No. It is a multiviewer, not a video wall controller. It combines multiple sources on one screen but does not split one image across multiple displays.

Q: How many HDMI sources can I connect? 
A: You can connect up to four HDMI source devices.

Q: How many displays can I connect? 
A: You can connect up to two HDMI displays.

Q: Can Output A and Output B show different sources? 
A: Yes. Output A and Output B can each select HDMI Input 1, 2, 3, or 4.

Q: Can I show all four HDMI inputs on one screen? 
A: Yes. Use 2x2 four equal picture mode to show all four HDMI inputs on one screen.

Q: Can I show two HDMI sources side by side? 
A: Yes. Use left/right picture mode.

Q: Can I show two HDMI sources stacked vertically? 
A: Yes. Use up/down picture mode.

Q: Does it support PIP? 
A: Yes. PIP mode shows one main input with one smaller input window.

Q: Can I move the PIP window? 
A: Yes. Press the PIP button to cycle the small window position between screen corners.

Q: Does the HDS-402MV support seamless switching? 
A: Yes. The manual lists seamless switching support.

Q: Does the HDS-402MV support 4K@60Hz? 
A: No. It supports up to 4K@30Hz.

Q: Does the HDS-402MV support 8K? 
A: No. It does not support 8K.

Q: Does the HDS-402MV support 4K@120Hz? 
A: No. It does not support 4K@120Hz.

Q: What HDMI version does the HDS-402MV support? 
A: It supports HDMI 1.4.

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

Q: Does the HDS-402MV have audio output? 
A: Yes. It includes 3.5mm stereo audio output and Toslink / S/PDIF digital audio output.

Q: What audio formats are supported? 
A: The manual lists LPCM, AC3, and DTS audio support.

Q: Can I choose which input audio plays during multiview? 
A: Yes. Use the Audio button to select which source audio is played.

Q: What does long pressing the Audio button do? 
A: Long pressing the Audio button switches between 2.1CH and 5.1CH mode.

Q: What output resolutions can I select? 
A: The Scaler button switches between 1080p, 1600p, and 4K@30Hz output.

Q: What does the Full Screen button do? 
A: It switches between full-screen mode and keeping the original video ratio.

Q: Does the HDS-402MV remember the last setup after power off? 
A: Yes. The manual lists a power-off memory function that retains the last setup when the device is restarted.

Q: Does the HDS-402MV support RS-232 control? 
A: Yes. It supports RS-232 control.

Q: What is the default RS-232 baud rate? 
A: The default RS-232 baud rate is 57600.

Q: What is the Micro USB port used for? 
A: The Micro USB port is used for firmware updates, factory reset, RS-232 control, and third-party control terminal configuration.

Q: What is the Micro USB baud rate? 
A: The Micro USB control baud rate is 115200.

Q: What operating systems are supported for Micro USB control? 
A: The manual lists Windows 8.1 / 10 / 11 and macOS 10.10 or above.

Q: What should I do if there is no picture? 
A: Check that the power adapter is connected, the power switch is on, the HDMI input and output connections are correct, and try replacing the HDMI cables.

Q: What should I do if I see a splash screen or pink screen? 
A: Use a standard high-quality HDMI cable and keep cable length within the recommended limits.

Q: What HDMI cable length is recommended? 
A: The troubleshooting section states that for 1080p, input/output cable length should not exceed 10m to 10m, and for 4K@30Hz, it should not exceed 5m to 5m.

Q: Does the HDS-402MV need external power? 
A: Yes. Connect the included 5V/2A power adapter.