USB to RS485 module serial port debugging converter bidirectional communication with TVS protection, industrial grade, compatible with Windows 7/10

USB to RS485 module

Speed: Theoretical 500Kbps, tested 2Mbps (Note 1) Distance: Theoretical 1200 meters, limited by conditions , tested up to 500 meters (Note 2) Stable & Reliable: Uses the mature and stable CH340 chip with multiple protections; self-recovery fuse protects the vulnerable host; bus TVS for ESD and surge protection.

Note 1: Test conditions: Two modules connected back-to-back, using ordinary unshielded cable, 20cm length. Note 2: Test conditions: Two modules connected back-to-back, baud rate 115200, using 0.3mm * 2-core shielded twisted pair cable. Practical application: Performance can be affected by cable material, baud rate, environmental interference, and other factors.

Driver Installation

Some systems are plug-and-play and will generate a COM port automatically. Otherwise, a driver needs to be installed. Download the driver from the official website:

  1. Visit the chip manufacturer's website in your browser: [download](https://115cdn.com/s/swwxub8339r?password=z7f1&# Driver) Access Password：z7f1
  2. Click on 【Services Support】 at the top -> 【Downloads】
  3. Click on 【Drivers】 on the left side
  4. Select category 【USB to Serial Port】, model 【CH340】, click 【Search】 (CH340 uses the CH341 driver)
  5. Port Lookup
  6. Click the driver corresponding to your system, download after the page redirects, install, and restart.

Common Issues

  1. Failure to open the serial port, possibly because it is occupied. A single serial port cannot be opened by multiple programs/software simultaneously.
  2. Checking the Port: Right-click on 'My Computer' (or 'This PC') -> Manage -> Device Manager -> Ports (COM & LPT)
    • IDE ATA/ATAPI controllers
    • USB Serial Port (COM2)
    • USB-SERIAL CH340 (COM2)
    • ... (Other potential listings)
    • Communications Port (COM1)
  3. How to Wire: 485 devices can communicate in parallel on a bus. Only two wires are needed: one connects to the A terminal of all devices, the other connects to the B terminal of all devices. Different devices might use different labels, common ones include: A / A+ / D+ / DATA+ / 485+ / T/R+ B / B- / D- / DATA- / 485- / T/R-
  4. How to Power: The module draws power from the USB port and does not require an external power supply. The SY/GND terminals on the module are the USB positive and negative outputs, with limited current capability.
  5. Data Direction: Automatically controls data transmission and reception, no user intervention needed.
  6. How to Change the Port Number: In Device Manager, right-click on the current port, select Properties -> Port Settings -> Advanced -> COM Port Number -> OK.

Dimensions

USB to RS485 module