USB TO RS485/422

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USB TO RS485/422
USB TO RS485 422.jpg

FT232 RS485 RS422
RS422, RS485






USB TO RS485/422, an industrial-grade USB to RS485/422 isolated converter, adopts the original FT232RNL, an industrial rail case design, built-in protection circuits such as power isolation, ADI magnetic coupling isolation, and TVS. USB TO RS485/422 is easy to operate, and can automatically transmit and receive without delay. It features fast communication speed, stability, reliability, and safety, which can be applied to various industrial control devices or applications with high communication requirements.


  • Onboard Original FT232RL and SP485EEN chip. Fast communication, stable and reliable, better compatibility.
  • Onboard unibody power supply isolation, provides stable isolated voltage and needs no extra power supply for the isolated terminal.
  • Onboard unibody digital isolation, allows signal isolation, high reliability, strong anti-interference, and low power consumption.
  • Onboard TVS (Transient Voltage Suppressor), effectively suppresses surge voltage and transient spike voltage in the circuit, lightning-proof & anti-electrostatic.
  • Onboard self-recovery fuse and protection diodes, ensure the current/voltage stable outputs, provide over-current/over-voltage proof, and improve shock resistance.
  • Onboard 15KV ESD isolation protection and 600W lightning-proof & anti-surge protection.
  • Onboard 120R terminal resistor on the RS485/RS422 ports, enable by default, configurable by jumper.
  • 3x LEDs for indicating the power and transceiver status.
  • Industrial rail-mount ABS case design, small in size, easy to install, and cost-effective.


Model Industrial grade isolated USB to RS485/422 converter
Baud Rate FT232RNL 300bps ~ 3Mbps
Host Port USB
Device Port RS485/422
USB Port Operating Voltage 5V
Interface Type USB-B
Connector 200mA self-recovery fuse, ESD protection
Transmission Distance About 5m
RS485/422 Interface Interface Screw Terminal
RS485 Interface A+, B-, PE
RS422 Interface TA, TB, RA, RB, PE
Direction Control Hardware automatic control
Interface Protection 600W lightningproof, anti-surge, and 15KV ESD protection (onboard 120R balancing resistor)
Transmission Distance About 1200m (at low rates)
Transmission Mode Point-to-multi points (up to 32 nodes, it is recommended to use repeaters for 16 nodes or more)
Indicator PWR Red power indicator, lights up when there is a USB connection and voltage is detected
TXD Green TX indicator, light up when the USB port sends data
RXD Blue RX indicator, lights up when the device ports send data back
Operating Environment Temperature Range -15℃ ~ 70℃
Humidity Range 5%RH~95%RH
Operating System Mac, Linux, Android, WinCE, Windows 10 / 8.1 / 8 / 7 / XP
Appearance Enclosure Rail-mount ABS case, suitable for 35mm DIN rail
Outline Dimensions 81.9 × 54.0 × 32.0mm

Interface Introduction

Interface PE TA TB RA RB
RS422 Signal ground Send differential signal positive T+ Send differential signal negative T- Receive differential signal positive R+ Receive differential signal negative R-
RS485 Signal ground Differential signal positive A+ Differential signal negative B- NC NC

USB-TO-RS485 422-intro.gif
USB-TO-RS485 422-intro-bottom.png

120R Matching Resistor Setting Description

USB TO RS485700.jpg

Description: The RS422 and RS485 interfaces of this product also have a built-in 120R enabling resistor, which is enabled by default, and the user can remove the case to modify the settings as needed.
Modification method: Modify the yellow jumper cap at the red frame.


USB TO RS485701.jpg

Software Installation

USB Driver Installation

  • The first method: download the driver wizard from the Internet, and automatically detect and install the driver.
  • The second method: Manually install the driver (the following uses WIN7 installation as an example).
  • Connect the device to the computer via a USB cable, and check the device manager, the serial port number has a yellow exclamation mark, indicating that the driver is not installed.

USB TO RS4852-2.png

  • You can download the software installation package on the official website WIKI, (There must be a path here) Double-click USB TO RS485-3.png.

USB TO RS485-4.png

  • Click Extract:

USB TO RS4825-5.png

  • Click Next:

USB TO RS4852-6.png

  • Check I accept this agreement (A), and then click Next:

USB TO RS4852-8.png

  • Click Finish, and check the computer device manager at this time, you can see that the port number is already available for normal use.

USB TO RS4852-9.png

Hardware Test

Test environment: PC (Windows system)
Required accessories:

  • USB TO RS485/422 x 2pcs
  • Adapter cable

RS485 test

  • Connect the RS485 interface of the USB TO RS485/422 module, that is, connect TA --> TA to TB --> TB. The hardware connection diagram is as follows:

USB-TO-RS485 422-RS485Test1.JPG

Note: The RS485 interface of this product also has a built-in 120R enabling resistor, which is turned on by default. Users can remove the case to modify the settings according to their needs. If signal isolation is required, PE can also be connected to the ground.

  • Open two SSCOM serial port debugging assistants on the computer, open the corresponding port number, set the same baud rate, and click Send at regular intervals to receive and send normally. The test results are shown in the figure below:

USB TO RS4852-11.png

RS422 Test

  • Connect two sets of USB TO RS485/422 together for communication. When the RS422 interface is connected, cross-connection is required, as shown in the figure below:

USB-TO-RS485 422-RS485Test202.JPG

Note: The RS485 interface of this product also has a built-in 120R enabling resistor, which is turned on by default. Users can remove the case to modify the settings according to their needs. If signal isolation is required, PE can also be connected to the ground.

  • On the PC, open two SSCOM, open the corresponding port number, set the same baud rate, and click Send at regular intervals to send and receive normally. The screenshot of the software is shown below:

RS232 TO RS485 (B) Spec07.jpg






  • If you encounter a system other than windows that cannot be used normally, you can enter the official website link below and use it after installing the corresponding system driver:

  • Compatible with multiple systems, support Win7/8/8.1/10, Mac, Linux, Android, WinCE, and other systems.

  • Remove the 120-ohm terminal resistor of RS485.


Yes, if you need to modify the 120R resistor, you can remove the case for setting, see the yellow jumper cap at the red box in the picture below:

  • Remove the two 120Ω terminal matching resistors of RS422/RS485, and connect the jumper cap to NC.

USB TO RS485422 FAQ07.png



RS422 is a full-duplex communication, you can loopback test to confirm the module function:
USB TO RS485-422 FAQ08.png
USB TO RS485-422 FAQ09.png



Technical Support

If you need technical support or have any feedback/review, please click the Submit Now button to submit a ticket, Our support team will check and reply to you within 1 to 2 working days. Please be patient as we make every effort to help you to resolve the issue.
Working Time: 9 AM - 6 PM GMT+8 (Monday to Friday)