RS232 TO RS485 (D)

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With LED Indicator
RS232 TO RS485 (D).jpg
Without LED Indicator
RS232 TO RS485 (B).jpg

RS485, RS232
RS232 to RS485




The RS232 TO RS485 (D) is an industrial-grade DIN-rail active opto-isolated RS232 to RS485 converter.


  • Compatible with RS232/RS485, convert RS232 signal to balanced and differential RS485 signal.
  • Stable transmission rate with a stable speed of 300~115200bps
  • Onboard unibody power isolation, provides stable isolation voltage, and there is no external power supply for the isolated terminal.
  • Onboard unibody digital isolation, provides signal isolation with high reliability, strong anti-interference and low power consumption.
  • Onboard TVS (Transient Voltage Suppressor), effectively resists the surge voltage and transient peak voltage in the circuit and provides lightninggproof and ESD protection.
  • Onboard self-recovery fuse and protection diodes, ensure stable output of current and voltage, overcurrent and overvoltage protection, improves anti-shock capability.
  • Onboard RS485 output terminal 120R, switch via jumper caps.
  • Onboard power supply screw terminal, support 5V~36V DC wide-voltage range power input.
  • Industrial grade ABS eco-friendly case, compact size, easy to install and cost-effective.

Version Options

RS232 to RS485 d-ver.png


Model Galvanic isolated RS232 to RS485 serial port converter
Power port Supply voltage 5V ~ 36V
Protection Anti-reverse
Reliable Baudrate 300~115200bps
Device Interface Compatible with RS232/RS485 standard
RS232 Interface Screw terminal
Protection ESD tube protection, anti-surge and ESD protection
Transmission Distance about 15m
Transmission Mode Point to point
RS485 Interface Screw terminal
Direction Control Hardware automatic control
Protection Provide 600W lightningproof, anti-surge and 15KV ESD protection
Transmission Distance about 1200m
Transmission mode Point-to-multi-point (up to 32 nodes, add the relay for up to 16 nodes)
Indicator PWR Power indicator, connect to the power port, the red indicator is on when the voltage is detected
TXD TX indicator, the green indicator is on when data is sent from RS232 interface
RXD RX indicator, the blue indicator is on when data is received from RS232 interface
Appearance Case Rail-mount ABS eco-friendly case, suitable for 35mm DIN rail
Dimensions 91.6 × 58.7 × 23.3mm

Application Topology

RS232 TO RS485 D -APP.png

Onboard Interface

RS232 TO RS48511.jpg

VCC Power input
DC 5V ~ 36V Power Supply
120R 120R Enable Pin Header
GND Ground/ RS232 Signal Ground SGND RS485 Signal Ground
TXD RS232 Signal Transmitting Pin A+ RS485 Differential Signal A+
RXD RS232 Signal Receiving Pin B- RS485 Differential Signal B-

Communication Connection Diagram

RS232 to RS485 Interface Conversion, Point-to-Point, Half-Duplex Communication for Interface Conversion

2024-07-11 171222.png

RS232 to RS485 Interface Conversion, Point-to-Multipoint, Half-duplex Communication, Suitable for Expanding Communication Nodes

2024-07-11 171451.png

Point-to-point, Half-duplex Communication via Two RS232 to RS485 Interface Conversions, Suitable for Extending RS232 Communication Distance

2024-07-11 171701.png


Note: RS232 TO RS485 (B) and RS232 TO RS485 (D) are based on the same case mold and have the same outline dimensions, while model D has additional indicator holes.

Hardware Test

Test Description

Test environment: PC (Windows OS)
Test hardware:

  • RS232 TO RS485 (D)
  • USB TO RS485
  • PC (If the computer does not have an RS232 interface, you can choose USB to RS232 (female connector male plug) to test the adapter.)

Test Hardware Connection

The RS232 interface of RS232 TO RS485 (D) connects to the PC with a serial extension cable or USB TO RS232 cable (female connector male plug). The RS485 interface is connected to RS232 TO RS485 (D). The USB interface of USB TO RS485 connects to the same PC and automatically tests. The hardware connection diagram is shown as below:
2024-07-11 173349.png

Note:The RS485 interface of this product also comes with 120R switch, and it is switched off by default. Users can switch it on/off through jumper wires; if you want the signals to isolate the ground, you should connect to the GND.

  • On the PC, open two SSCOMs, open the corresponding port number, set the same baud rate, and click on the timing send, you can send and receive normally, the software test screenshot is as follows:

USB TO RS232 485 test06.jpg




Technical Support

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