TTL TO RS232 (B)

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TTL TO RS232 (B)
TTL TO RS232 (B).jpg

TTL To RS232
TTL, RS232





TTL TO RS232 (B) is an industrial-grade rail-mounted electrically isolated TTL-to-RS232 serial converter.


  • Compatible with TTL/RS232 standard, converting the TTL signal into a balanced differential RS232 signal, supporting full-duplex communication.
  • Compatible with 3.3V ~ 5V TTL signal level, with anti-reverse connection and anti-over-voltage circuit on the power supply side.
  • 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, and with lightning-proof and ESD protection.
  • Onboard protection diodes, ensure the current/voltage stable outputs, provide over-current/over-voltage protection, and improve shock resistance.
  • Onboard power supply screw terminal for 3.3V~5V DC input.
  • Industrial rail-mount ABS case design, small in size, easy to install, and cost-effective.


Model Galvanic isolated TTL To RS232 converter
Power Port Power supply 3.3V ~ 5V
Interface Protection Anti-over-discharge, reverse-proof
Device interface Compatible with TTL / RS232 standard
TTL Interface Interface Screw terminal
Transmission distance Less than 10m
Transmission model Point to point
RS232 Interface Interface Screw terminal
Protection TVS diode protection, anti-surge and ESD protection, power and digital isolation
Transmission Distance About 15m
Transmission Mode Point-to-point
Indicator PWR Power indicator, lights up red when the input voltage is detected
TXD TX indicator, lights up when the TTL port sends data
RXD RX indicator, lights up when the TTL port receives data
Product Appearance Case Rail-mount ABS case, suitable for 35mm DIN rail
Dimensions 91.6 × 58.7 × 23.3mm

Primary Function

Convert the TTL signal into RS232 signal, which can be used for interface conversion and can also be used to extend the communication distance.
TTL TO RS232 (B) 012.png

Interface Introduction

TTL TO RS232 (B)101.png

VCC Power Input
DC 3.3V~5V power supply
SGND RS232 Signal Ground
GND Ground / TTL signal ground
TXD TTL transmit data pin TXD RS232 transmit data pin
RXD TTL receive data pin RXD RS232 receive data pin

Communication Connection Diagram

TTL convert to RS232, point-to-point, full-duplex communication, suitable for interface conversion

TTL TO RS232(B)017.png

Two groups TTL To RS232 conversion, point-to-point, full-duplex communication, suitable for extending the communication distance of TTL

TTL TO RS232 (B)018.png


TTL TO RS232 01.jpg

Hardware Test

Test Note

Test Environment: PC (Windows).
Accessories required for testing:

  • TTL TO RS232 (B) —— This product
  • USB TO TTL - not included
  • PC (if your PC does not feature the RS232 interface, you can choose USB to RS232 (female socket male pin) for adapter test)

Test Hardware Connection

Connect the RS232 interface of TTL TO RS232 (B) to the PC through the serial port cable or the USB to RS232 cable, connect the TTL interface of TTL TO RS232 (B) to the TTL interface of USB TO TTL, and then connect the USB port of USB TO TTL to the same PC for the self-transmission test. The schematic diagram of the hardware connection is as follows:
TTL TO RS232 B 02.png

Software Operation

  • Open two SSCOM interfaces.
  • Select two corresponding COM ports.

USB TO 4CH Serial Converter 07.png

  • Select the baud rate as 115200, input the characters to be sent, select "Show Time and Packet" to view it more intuitively, and then click on "Open COM".

USB TO 4CH Serial Converter 21.png

  • In these two SSCOM interfaces, select Send Every 100ms, and you can see the effect.

USB TO 4CH Serial Converter 11.png




Tested to work stably with baud rate up to 1M.



Technical Support

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