An Ethernet-to-UART module converts network data into serial data and is commonly used to connect legacy serial devices that don't support Ethernet to a network. Here are some common Ethernet-to-UART modules:

WIZ610WI

Features
Based on the W5100S-E/SJ Ethernet controller, supports the TCP/IP protocol stack.
Operating voltage: 3.3V, interface type: UART (TTL level), baud rate range: 300bps to 4,608,000bps.
Supports multiple network protocols, has a built-in unique MAC address, and operates in an operating temperature range of -40°C to +85°C.
Applications
Sensor data acquisition and remote control in industrial automation systems.
Network connectivity for smart home devices.

WIZ750SR-110

Features
Based on the Wiznet W7500 chip, with a built-in TCP/IP protocol stack.
Operating voltage: 3.3V to 5.25V, communication interface: one UART (TTL level), network interface: RJ45.
Supports multiple communication modes with a baud rate range of 300bps to 921.6Kbps and features a hardware watchdog function.
Applications
Industrial automation control, such as data transmission for PLCs, HMIs, and other human-computer interaction devices.
Remote monitoring systems, such as networking for security cameras and environmental monitoring sensors.

HLK-RM04

Features
Low-cost embedded UART-ETH-WIFI module with a built-in TCP/IP protocol stack.
Supports conversion between serial ports, Ethernet, and wireless networks (WIFI), with two Ethernet ports, two serial ports, one USB port (host/slave), and GPIO.
Supports IEEE 802.11n/g/b for wireless and IEEE 802.3/3u for wired.
Applications
Network connectivity and data transmission for IoT devices.
Wireless data transmission for remote monitoring systems.

ATK-UART2ETH

Features
Produced by Shenzhen Anxinke Technology Co., Ltd., it supports serial-to-Ethernet conversion.
Utilizing the STM32F107 chip and ENC28J60 Ethernet controller, it is compatible with multiple network protocols, including TCP/IP, UDP, and HTTP.
It supports multiple operating modes, including server mode, client mode, and UDP broadcast mode.
Applications
Remote monitoring and data upload.
Network connectivity for IoT devices.

These modules convert Ethernet data to UART data, enabling Ethernet connectivity for traditional serial devices. They are widely used in industrial control, smart home, and IoT applications.