USB TO RS232/485 (B)

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USB TO RS232/485 (B)
USB TO RS485 422-B.jpg

RS485 RS422






USB TO RS232/485 (B), 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 RS232/485 (B) 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 120R terminal resistor on the RS485/RS422 ports, enabled 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.


Product Type Industrial Isolated USB to RS232/RS485 converter
Host Interface USB
Device Interface RS232/RS485
USB Interface Operating Level 5V
Interface USB-B
Protection 200mA self-recovery fuse, isolated output
Transmission Distance About 5m
Isolated RS232 Interface Form Factor Screw terminal
Transmission Distance About 15m
Transmission Mode Point to point
Baud rate 300 bps ~ 921600bps
Isolated RS485 Interface Form factor Screw terminal
Direction Control Hardware automatic control
Protection Provide 600W lightningproof, anti-surge and 15KV ESD protection (onboard 120R balancing resistor)
Transmission Distance About 1200m (at low rate)
Transmission Mode Point to multi-point (up to 32 nodes, add a relay for up to 16 nodes)
Baud Rate 300 bps ~ 921600bps
Indicator PWR Power indicator, connect to USB, the red LED is on when the voltage is detected
TXD Tx indicator, green LED is on when data is sent from the USB port
RXD Rx indicator, blue LED is on when data is sent from the device port
Usage Environment Temperature range -15℃ ~ 70℃
Humidity range 5% ~ 95%RH
OS Mac, Linux, Android, Windows 11 / 10 / 8.1 / 8 / 7
Appearance Case Rail-mount ABS eco-friendly case, for 35mm DIN rail
Dimensions 81.9 × 54.0 × 32.0mm

Onboard Interface

USB RS Onboard Interface.png


USB TO RS4857b.jpg

Driver Installation

USB Driver Installation

  • Download the driver file VCP Driver.
  • Double-click CDM212364_Setup.exe to install it following the steps below:
  • Click on Extract, and then "Next".

USB TO RS485-4.png
USB TO RS4825-5.png

  • Click on "I accept this agreement" and Next, and then Finish.

USB TO RS4852-6.png
USB TO RS4852-8.png

  • After connecting to the PC, you can see the available port on the device manager:

USB TO RS4852-b.jpg

Hardware Test

Test environment: PC (Windows system)
Required accessories:

  • USB TO RS485/422 (B) x 2pcs
  • USB Type-A to Type-C
  • Cables

RS232 test

  • To connect the RS232 port of the USB TO RS232/485 (B) module, connect RXD to TXD, and GND to GND. Refer to the connection diagram below:

Hardware Test-usb.jpg

  • Open two SSCOM serial port debugging assistants on the computer, and open the corresponding port number.

USB TO 4CH Serial Converter 15.png

  • Select the baud rate as 115200, input the characters to be sent, and is better to select the "Show time and package", and open the serial port.

USB TO 4CH Serial Converter 16.png

  • Both select the 100ms of the SSCOM, and you can see the normal data transmission in these two Windows, and the testing effect:

USB TO 4CH Serial Converter 11.png

RS485 Test

  • Connect the RS485 port of the USB TO RS232/485 (B) module, i.e. A+ --> A+, B- --> B-, PE --> PE, and refer to the connection diagram below:

USB TO RS232-485-b test.jpg

  • Open two SSCOM windows, and open the corresponding port number.

USB TO 4CH Serial Converter 07.png

  • Select the baud rate as 115200, and input the characters to be sent, and it is better to check "show time and package", click on Open serial port:

USB TO 4CH Serial Converter 21.png

  • Select one SSCOM, send it in 100ms intervals, and then you can see the two windows transmit the data normally, and the testing effect as shown below:

USB TO 4CH Serial Converter 17.png





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