This module provides an easy way to communicate between TTL UART and Ethernet, allowing bi-directional transparent data transmission. Featuring castellated holes and highly integrated packaging for a compact and easy integration into a variety of applications. With its ease of use, multi-communication modes (TCP Server / TCP Client / UDP Multicast / UDP Mode) Modbus Gateway & NTP Protocol Support, a fast data rate, low power consumption and high stability. it's ideal for your next project! What's on Board Specifications Product Description Castellated holes module Basic Function Bi-directional transparent data transmission between serial port and Ethernet Ethernet Common network port Isolation Protection N/C UART Port TTL Power Supply Pinheader / pads Dimensions 34×23×11.5mm Application Scenarios Can be used as Serial server, Modbus gateway, MQTT gateway, suitable for applications like data acquisition, IoT gateway, safety & security IoT, and intelligent instrument monitoring. UART Specification - Baudrate 300 ~ 115200 bps Parity Bit None, odd, even, mark, space Data Bit 5 ~ 9 bits Flow Control Support Software - Protocol ETHERNET, IP, TCP, UDP, HTTP, ARP, ICMP, DHCP, DNS Configuration Host, web browser, device management functions library Communication Method TCP/IP direct communication, VCOM Operating Mode TCP server, TCP client, UDP Group, UDP Modbus Gateway Modbus TCP to RTU Other Functions User-defined heartbeat/registration packet, User-defined web page... Other - Operating Temperature -40℃ ~ 85℃ Humidity Range 5% ~ 95% relative humidity Resources * Product Wiki * UART TO ETH (B) Manual * MQTT and JSON Manual Pinout Pin Model Description 5V Power 5V Power Input 3.3V Power 3.3V Power Input GND Ground Ground RST Reset Reset pin, low active. It is recommended to use max811reus or a similar reset chip. Noise can be filtered by a 0.1u capacitor. Low-level minimum time 100ns. TXD OUT Serial data transmitting pin of the module, 3.3V TTL level, can be connected to RXD of user MCU. RXD IN Serial data receiving pin of the module, 3.3V TTL level, can be connected to the user MCU's TXD. DEF IN When the parameter is reset to 0 and held for more than 1 second, the module will restart with the default IP of 192.168.1.254, static IP mode, 255.255.255.0 gateway, and 192.168.1.1 gateway. You can also set your own reset parameters with the param.txt configuration file. RUN OUT Working indicator, the chip works properly, and will output a square wave with a period of 2 seconds. You can connect a 4.7K resistor and then connect the LED to the ground and the LED is on indicating the chip has been working. EN OUT The 485 transmit controller, normally 0, becomes 1 when the module sends data to the serial port. It can be connected directly to the TXDEN pin of the MAX485 chip. RTS OUT Hardware flow control output. After the flow control is set to CTS/RTS, DTR/DSR, RTS=0 normally, if RTS=1, it means the module can't receive data and the user MCU should stop sending data to the module. CTS IN Hardware flow control input, when the chip is configured for CTS/RTS, DSR/DTR serial mode, only when CTS=0, the chip serial port will output data to the outside. GND Ground Ground LINK2 OUT When it is 0, it indicates that the module RJ45 network cable is connected. ACT OUT Data indicator. When it is 0, it indicates that there is data being sent and received at the serial port. But when there is data, this pin will jump between 0 and 1. ACT=1, which cannot be used as a flag for no data communication. LINK OUT TCP connection indicator. When it is 0, the module has established TCP/UDP connection with the network server, and the module can send and receive data normally. If the network cable is unplugged at this time, the LINK will change to 1. Package Contents * 1x TTL UART to Ethernet Mini Module * 1x 10-Pin Black pin header (2 Pack) https://elecena.pl/product/23496338/ttl-uart-to-ethernet-mini-module 2023-05-20 https://elecena.pl/product/23496338/ttl-uart-to-ethernet-mini-module 2023-12-27 https://elecena.pl/product/23496338/ttl-uart-to-ethernet-mini-module 2024-09-18 https://elecena.pl/product/23496338/ttl-uart-to-ethernet-mini-module 2024-11-29 https://elecena.pl/product/23496338/ttl-uart-to-ethernet-mini-module 2024-11-30 https://elecena.pl/product/23496338/ttl-uart-to-ethernet-mini-module 2025-02-13 https://elecena.pl/product/23496338/ttl-uart-to-ethernet-mini-module 2025-08-05 https://elecena.pl/product/23496338/ttl-uart-to-ethernet-mini-module 2025-11-28 https://elecena.pl/product/23496338/ttl-uart-to-ethernet-mini-module 2025-11-29