











RS232 to RJ45 Ethernet Module
Rail-mount RS232 serial server

Version Options
RS232 TO ETH (B) ![]() |
RS232 TO POE ETH (B) ![]() |
These two versions are the same in software functions, while RS232 TO POE ETH (B) is the hardware upgrade version, support PoE Ethernet port power supply.

Features
This is a RS232 device data acquisitor / IoT gateway designed for industrial environment. It combines multi functions in one, including serial server, Modbus gateway, MQTT gateway, RS232 to JSON, etc. The module features RS232 and Ethernet port(POE function is optional), uses screw terminals for power input. Rail-mount case design, small in size, easy to install. It is suitable for applications like data acquisition, IoT gateway, safety & security IoT, and intelligent instrument monitoring...
Specifications
Product | RS232 TO ETH (B) | RS232 TO POE ETH (B) |
---|---|---|
Product Type | Serial server, Modbus Gateway, MQTT Gateway | |
Basic Function | Bi-directional transparent data transmission between RS232 and Ethernet | |
Communication interface | RS232 port x 1, Ethernet port x 1 | |
Power supply | 6 ~ 36V DC screw terminal | 6 ~ 36V DC screw terminal, or PoE port |
Isolation Protection | Power isolation, Signal isolation | |
Communication | ||
Ethernet | common network port | PoE network port, support IEEE 802.3af standard |
10 / 100M auto-negotiation RJ45 connector, 2 KV surge protection | ||
Serial port | Isolated RS232 | |
Serial specification | ||
Baudrate | 300 ~ 115200 bps | |
Parity bit | none, odd, even, mark, space | |
Data bit | 5 ~ 9 bits | |
Flow control | N/A | |
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 (coexisting with TCP server), UDP, UDP multicast | |
Others | ||
Operating temperature | -40℃ ~ 85℃ | |
Humidity range | 5% ~ 95% relative humidity | |
Dimensions | L × W × H: 87 × 36 × 59 mm |
Primary function
bi-directional transparent data transmission between RS232 and Ethernet

Rail-mount support
easy to combine multi rail-mounted serial server together, more freely

Modbus gateway support
suitable for Modbus gridding upgrade, Can Be Used With Specific Configuration Software

Multi communication modes
supports TCP server / TCP client / UDP mode / UDP multicast


MQTT/JSON to Modbus
more flexible conversion between different protocols

When used as MQTT gateway, the devices can upload serial data to MQTT server by MQTT protocol through transparent transmission, supported servers including Baidu Cloud MQTT, Alibaba Cloud MQTT, China Mobile OneNet, etc. The acquired Modbus RTU or non-standard serial data can be parsed into JSON format and packaged into MQTTdata packet for uploading.
When used as JSON data acquisition gateway, the devices can be connected to data acquisition instruments through RS232 connection, then acquire data automatically, convert the data into JSON format, and finally post it to server. The acquired data supports Modbus RTU 645 instrument 97 version, 645 instrument 07 version, as well as sorts of non-standard RS232 protocols. The uploaded data format can be configured via host, and the JSON upload protocol can be MQTT protocol, HTTP POST protocol, HTTP GET protocol, and so on.
Multi hosts roll-polling support
different network devices will be identified and responsed respectively,
no more crosstalk issue while communicating with multi network devices

User-defined heartbeat/registration packet
easy for cloud communication and device identification

NTP protocol support
getting network time info for serial output or data upload

Multi configuration methods
supports Web browser configuration, obtaining dynamic IP via DHCP,
DNS protocol connected domain server address

Interface introduction

Outline dimensions

Resources
Wiki: www.waveshare.com/wiki/RS232_TO_ETH_(B)
Wiki: www.waveshare.com/wiki/RS232_TO_POE_ETH_(B)
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Shopping Cart
I received the order within one day, in good condition.
Nice Product
I've been shown the "free shipping over 999" banner but haven't been given free shipping. It's OK to charge shipping but do keep a proper disclaimer about which areas are served free.
Also, after this order was received, I wanted to place another order, before which I got 2 emails about Rs. 5 store credit. I should be getting a 10rs discount, but there's not a place on the website or app where I can redeem this amount.
Please improve. Don't unnecessarily make promises and spoil the brand's reputation. If this is on social media, it'll be a very bad look.