Din Rail "Lipstick" RS485 to Ethernet Serial Device Server Modbus Gateway RTU to TCP Rich Protocols MQTT/TCP/UDP/HTTP Edge Computing USR-DR134

Listing falsely states it supports MQTT. A newer model does, but the one shipped does not and can’t be upgraded via firmware to support it. Support will send you a link to another site to purchase the updated model.

I recently integrated the PUSR USR-DR134 "Lipstick" RS485 to Ethernet Serial Device Server into my industrial automation setup, and it's been performing exceptionally well. Despite its compact size—comparable to a lipstick tube—it offers robust functionality. The device facilitates seamless two-way transparent data transmission between RS485 serial ports and Ethernet, supporting protocols like MQTT, TCP, UDP, and HTTP. Its Modbus gateway capability allows for easy conversion between Modbus RTU and Modbus TCP protocols, simplifying communication with PLCs and SCADA systems. Installation was straightforward, thanks to the DIN rail mounting and push-type connectors. Operating reliably in various environments, this converter has proven to be a reliable solution for integrating serial devices into an Ethernet network

This gateway works as a modbus bridge both in IP master or RTU master modes. However it only supports modbus queries of 123 registers or less. Modbus standard is 125 registers. If you are doing a single request of less than that it will work but if you are polling large, sequential, register blocks this device will fail. I've emailed support with the issue with no answer. I will update my review