TTL TO RS485 (C)

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TTL TO RS485 (C)
TTL TO RS485 (C).jpg

TTL, RS485
TTL to RS485





TTL TO RS485 (C) is a mini galvanic isolated TTL-to-RS485 serial converter.


  • Compatible with TTL/RS485 standard, converting the TTL signal into differential RS485 signal, supports half-duplex communication.
  • Compatible with 3.3V ~ 5V TTL signal level, provides over-voltage protection for power supply interface.
  • 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, low power consumption.
  • Onboard TVS (Transient Voltage Suppressor), effectively suppresses surge voltage and transient spike voltage in the circuit, lightningproof & anti-electrostatic.
  • Onboard self-recovery fuse and protection diodes, ensure the current/voltage stable outputs, provide over-current/over-voltage protection, improve shock-proof performance.
  • Onboard RS485 output terminal 120R resistor, enabled via soldering.
  • Black immersion gold process design, compact size, easy to integrate.


Model Galvanic isolated TTL To RS485 converter
Power Port Power supply 3.3V ~ 5V
Interface Protection anti-over-discharge
Device interface Compatible with TTL / RS485 standard
TTL Interface Interface type Screw terminal
Transmission distance Less than 10m
Transmission model Point to point
RS485 Interface Interface Protection Provide 200W lightningproof, surge-suppress and 6KV ESD protection
Terminal Resistance 120R, enabled via soldering
Transmission Distance About 1200m
Transmission Mode Point-to-multipoint (up to 32 nodes, it is recommended to use repeaters for 16 nodes or more)
Appearance Dimensions 42.8 x 15.2 x 4.75mm

Primary Function

Convert the TTL signal into a balanced differential RS485 signal, which can be used for interface conversion and node expansion, and can also be used to extend the communication distance.
TTL TO RS485 (C) 012.png

Onboard Interface

R (RXD) RX indicator, lights up when the TTL port receives data
T (TXD) TX indicator, lights up when the TTL port sends data
P (PWR) Power indicator, lights up when there is a power supply connection and voltage is detected


PE RS485 Signal Ground GND Ground
RXD TTL Signal Receiving Pin
B- RS485 Differential Signal Negative B- TXD TTL Signal Transmitting Pin
A+ RS485 Differential Signal Positive A+ VCC Power Input
DC 3.3V ~ 5V Power Supply

Communication Connection Diagram

TTL convert to RS485, point to point, half-duplex communication, suitable for interface conversion

TTL TO RS485 (C)017.jpg

TTL convert to RS485, point-to-multipoint, half-duplex communication, suitable for expanding nodes

TTL TO RS485 (C)018.jpg

Two groups TTL To RS485 conversion, point-to-point, half-duplex communication, suitable for extending the communication distance of TTL

TTL TO RS485 (C)019.jpg


TTL TO RS485 C 01.jpg

Hardware Test

Test Note

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

Test Hardware Connection

Connect the RS485 interface of TTL TO RS485 (C) to the PC through the USB to RS485 cable. Connect the TTL interface of TTL TO RS485 (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 RS485 C 02.jpg

Note: The RS485 interface of this product is also equipped with 120R enable switch, the default setting is on, the user can set it according to the needs (set up to open, set down to NC), if signal isolation is required, you can connect GND to ground.

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.

RS232 TO RS485 (B) Spec07.jpg

Note: RS485 is a half-duplex communication, and the sending and receiving test cannot be performed at the same time.




Test within 2M baud rate can work stably.
The hardware itself does not limit the usage rate but mainly depends on the access to the TTL and RS485 devices, as well as the communication environment and communication distance and other factors.



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)