T121 KVM Switch Manual--V0.1

Product Overview

T121 is a 2x1 HDMI KVM switch that allows you to easily integrate cross-platform computer devices and significantly simplify device management.

Key Features

Key Features

  • Device Integration: Control 2 computers using 1 monitor and 1 set of keyboard and mouse
  • High-Definition Resolution: Supports up to 4K (2160p) @60Hz
  • HDMI 2.0: Complies with HDMI 2.0 standard
  • Wide Compatibility: Supports Unix/Windows/Debian/Ubuntu/Fedora/MacOS X/Raspbian/Ubuntu for Raspberry Pi and other Linux systems
  • High-Speed USB Transfer: Supports multiple USB 3.2 Gen 1 expansion ports for high-speed data transfer
  • Hot-Swap Support: Connect or disconnect devices at any time without turning off the computer
  • Multiple Switching Methods: Supports front panel buttons, keyboard hotkeys, and mouse wheel control for KVM switching input ports
  • Keyboard and Mouse Modes: Supports pass-through mode and legacy emulation mode, significantly improving keyboard and mouse compatibility

Package Contents

  • 1 x 2x1 HDMI KVM Switch
  • 2 x USB 3.0 Cables
  • 1 x DC 12V Power Adapter
  • 1 x User Manual
  • 4 x Anti-Slip Pads
Note: After receiving the product, please carefully check the package list to ensure no components are missing and the product was not damaged during shipping. If you have any questions, please contact us at: support@tesmert.com

Hardware Overview

Front Panel Layout

Front Panel

a. 3.5mm Audio/Microphone Port - Integrated microphone and left/right audio output

b. USB 3.2 Gen 1 Port - Connect USB 3.0 devices

c. Display Status LED - Indicates the currently selected PC

d. Input Selection Button - Press to switch input source

e. Power Switch - Press and hold for approximately 2 seconds to turn power on or off

f. Control Port - Can be controlled via external keypad or UART commands

Rear Panel Layout

Rear Panel

g. DC 12V Power Port - 12V DC power input

h. LAN Port - Insert network cable to connect both input PCs to the local area network (100Mbps)

i. Keyboard/Mouse Input Port - For USB keyboard and mouse input

j. HDMI Output Port - Connect 1 HDMI monitor for video output

k. KVM Input Port Group - Each group contains 1 HDMI port and 1 USB port, connect corresponding input devices for signal input

Quick Start Guide

Step 1: Physical Connections

Basic Connections

  1. Connect PC1: Use 1 USB-A to B cable and 1 HDMI cable to connect PC1 to the KVM input port group - USB-A end to PC, USB-B end to KVM
  2. Connect PC2 in the same manner
  3. Connect Monitor: Use 1 HDMI cable to connect the KVM HDMI output port to 1 HDMI monitor
  4. Connect Keyboard and Mouse: Connect external mouse and keyboard to the KVM keyboard/mouse input port
  5. Connect Power: Connect the power cable to the KVM DC 12V port and insert into power outlet

Optional Connections

  1. Connect USB Devices: Connect USB 3.0 devices to the KVM standard USB 3.0 port
  2. Connect Audio Devices: Connect external audio devices to the KVM left/right audio output ports
  3. Connect Network: Use 1 network cable, one end to the RJ45 port, the other end to a switch or router
  4. Connect Wired Remote Controller: Connect a wired controller (sold separately) to the Control port for switching

Step 2: Power-On Sequence

  1. Ensure all cables are properly connected
  2. Turn on the KVM power switch (press and hold for approximately 2 seconds)
  3. Turn on the monitor power
  4. Turn on the computer power
  5. The KVM switch will start working

Step 3: Initial Configuration

  1. Check the display status LED to confirm normal connection
  2. If you need to change display mode or resolution, go to the corresponding PC display settings to configure

Operation Guide

Basic Operations

Method 1: Front Panel Button Switching

Function Operation Feedback
Switch PC Press the input selection button LED lights up, indicating the current display is showing the corresponding PC

Method 2: Hotkey Switching

Hotkey trigger method: On the keyboard connected to the keyboard/mouse dedicated port, press the trigger key twice within 1 second to trigger the hotkey, then press the command key within 1 second to execute the command.

  • Switch to Specific PC: Press hotkey combination: RCtrl → RCtrl →1~4 to switch to the corresponding PC
  • Cycle Switching
  • - Press hotkey combination: RCtrl → RCtrl → PgUp to cycle forward through all connected PCs;
  • - Press hotkey combination: RCtrl → RCtrl → PgDn to cycle backward through all connected PCs;

Method 3: Mouse Wheel Switching

  • Step 1: Enable this function via hotkey combination RCtrl → RCtrl → F6
  • Step 2: Double-click the mouse wheel within 1 second to switch to the next PC

Basic Hotkeys

Basic Hotkeys

  • Select Previous Input Port: RCtrl → RCtrl → PgUp
  • Select Next Input Port: RCtrl → RCtrl → PgDn
  • Select by Port Number: RCtrl → RCtrl →1~2
  • Switch Keyboard/Mouse Mode: RCtrl → RCtrl →F2
  • Enable/Disable Built-in Network Card: RCtrl → RCtrl →F4
  • Enable/Disable Mouse Wheel Switching: RCtrl → RCtrl →F6
  • Enable/Disable Buzzer: RCtrl → RCtrl →F11
  • Customize Hotkey Trigger Key: RCtrl → RCtrl →F1→New trigger
  • Enable Auto Scan:RCtrl → RCtrl →Space
  • Increase Auto Scan Interval:RCtrl → RCtrl →+
  • Decrease Auto Scan Interval:RCtrl → RCtrl →-
  • Exit Auto Scan:ESC
Note: 1. Custom hotkey function is triggered by double-clicking Hotkey→ F1. After triggering, the buzzer will beep 5 times. Please press the new trigger key within the 5 beeps.
2. Each press of the auto scan interval hotkey increases/decreases the time by 1 second.
3. When hotkey settings are enabled, the buzzer beeps 2 times; when disabled, the buzzer beeps 1 time.

Advanced Features

Keyboard and Mouse Emulation Modes

Two keyboard and mouse modes are available: Pass-through mode and Legacy emulation mode.

  • Pass-through mode: Supports KM control software and multifunction keys
  • Legacy emulation mode: Ensures keyboard, mouse, and hotkey functions work properly, but does not support KM control software

Setup Process:

  1. Default mode is pass-through mode, which supports most keyboard/mouse drivers and multifunction keyboard/mouse
  2. If compatibility issues occur, you can switch to legacy emulation mode
  3. Switching method: Press RCtrl → RCtrl →F2
  4. It is recommended to restart the KVM after switching
Note: When switching to compatibility mode, the buzzer sounds 2 short beeps; when switching to pass-through mode, it sounds 1 short beep.

Built-in Network Switch

The 2x1 KVM switch has a built-in USB Ethernet adapter that adds standard RJ45 ports to all PCs connected to the KVM, allowing computers to connect to a router or network switch for 100Mbps wired network connection.

Setting Hotkey Function
Enable/Disable Built-in Network Card RCtrl → RCtrl →F4 Controls the network card status of the currently displayed PC
Default Status - Built-in network card is enabled by default
Note: It is recommended to connect the USB cable to a USB 3.0 or higher port on the PC to achieve 100Mbps bandwidth network connection.

Technical Specifications

General Specifications

  • Model: T121
  • Supported Computers: Can connect to 2 PCs simultaneously
  • Video Resolution: Up to 4K@60Hz, backward compatible with 1080P@60Hz/120Hz/144Hz
  • USB Standard: USB 3.2 Gen 1
  • Keyboard/Mouse Dedicated Port Standard: USB 1.1
  • Keyboard/Mouse Pass-through: Supported
  • Network: 100Mbps Ethernet
  • Audio: 3.5mm Audio/Microphone integrated port
  • EDID Emulator: Supported

Power Requirements

  • Input Voltage: DC 12V
  • Current: [3A max]

Physical Dimensions

  • Dimensions: [187mm×115mm×52mm]
  • Operating Temperature: [0°C to 55°C (32°F to 131°F)]
  • Storage Temperature: [-20°C to 65°C (-4°F to 149°F)]

Compatibility

  • Operating Systems: Unix/Windows/Debian/Ubuntu/Fedora/MacOS X/Raspbian/Ubuntu for Raspberry Pi and other Linux systems
  • Video Standard: HDMI 2.0
  • Keyboard Type: USB keyboard (supports pass-through and legacy modes)
  • Mouse Type: USB mouse (supports pass-through and legacy modes)

Troubleshooting Guide

Common Issues and Solutions

No Signal on Monitor

  1. Check if HDMI cable is firmly connected
  2. Confirm monitor is powered on and correct input source is selected
  3. Check if KVM power is working properly
  4. Try re-plugging the HDMI cable

Keyboard/Mouse Not Responding

  1. Confirm keyboard and mouse are connected to the correct USB port (keyboard/mouse input port)
  2. Try switching to legacy emulation mode: RCtrl → RCtrl →F2
  3. Restart the KVM switch
  4. Check USB cable connections

Network Connection Issues

  1. Confirm network cable is properly connected
  2. Check if built-in network card is enabled: RCtrl → RCtrl →F4
  3. Confirm USB cable is connected to PC's USB 3.0 port
  4. Check router/switch settings

Monitor Cannot Output Stable Video, Flickering/Black Screen

  1. Resolution / Refresh Rate Mismatch

T121 supports a maximum resolution of 4K@60Hz. If the computer output resolution/refresh rate exceeds the specifications (e.g., 4K@144Hz), it may cause unstable video output. You can manually reduce the resolution/refresh rate on the computer side.

  1. Device Connection

(1) Ensure HDMI cables between computer and monitor are firmly connected.

(2) Cables that are too long or of poor quality can cause signal attenuation. It is recommended to use the supplied HDMI cable for the computer, and the HDMI cable used for the monitor should not exceed 3 meters in length.

(3) Using conversion devices (dapters/converters/conversion cables) may cause compatibility issues and signal instability. Avoid using conversion devices if possible. If conversion devices must be used, avoid cascading conversion devices.

  1. EDID Reading Exception

If the KVM Switch does not correctly read the monitor's EDID data, the monitor cannot stably acquire the signal. You can try using an EDID emulator between the KVM Switch and monitor, or contact our after-sales technical support team for further diagnosis and assistance.

Audio Device Not Working Properly

  • Connection Requirements:

The audio function data transmission of the KVM Switch depends on the USB-B ports of PC1~4. Please ensure the USB cables are firmly connected to these two ports.

  • Computer Sound Output Settings:

(1) 3.5mm Headset Port: Select "USB Audio" in the computer's sound output device.

(2) USB 3.0 Port: Select the corresponding USB audio device in the computer's sound output device (the name is usually similar to USB Audio Device or USB Headset).

Note: If normal sound output still cannot be achieved after selecting "USB Audio" through the 3.5mm interface, you can use a USB sound card (USB to 3.5mm) to connect the audio device.

Warranty and Support

Limited Warranty

  • Duration: One (1) year from the date of shipment
  • Coverage: Material and workmanship defects
  • Exclusions: Damage caused by mechanical, electrical, or other abuse or modifications

If this product is proven to be defective under normal conditions during the warranty period, we will repair or replace the product. If a malfunction occurs under conditions not covered by the warranty, repairs will be made at the parts and labor prices in effect at the time of repair. Such repairs are warranted for six (6) months from the date of reshipment to the buyer.

Technical Support

  • Email: support@tesmert.com
  • Website: https://www.tesmert.com
  • Working Hours: [Please refer to the official website]
  • Online Resources: https://support.tesmert.com