--- product_id: 77775542 title: "Double Serial Device RS232 RS485 RS422 Ethernet Server Modbus to MQTT lot Gateway Multi-Host Polling USR-N520 H7 Version" brand: "pusr" price: "KSh23937" currency: KES in_stock: true reviews_count: 4 category: "Pusr" url: https://www.desertcart.co.ke/products/77775542-double-serial-device-rs232-rs485-rs422-ethernet-server-modbus-to store_origin: KE region: Kenya --- # 5-36V DC Modbus TCP 2 Ports Double Serial Device RS232 RS485 RS422 Ethernet Server Modbus to MQTT lot Gateway Multi-Host Polling USR-N520 H7 Version **Brand:** pusr **Price:** KSh23937 **Availability:** ✅ In Stock ## Summary > 🔗 Connect, Control, Conquer! ## Quick Answers - **What is this?** Double Serial Device RS232 RS485 RS422 Ethernet Server Modbus to MQTT lot Gateway Multi-Host Polling USR-N520 H7 Version by pusr - **How much does it cost?** KSh23937 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.ke](https://www.desertcart.co.ke/products/77775542-double-serial-device-rs232-rs485-rs422-ethernet-server-modbus-to) ## Best For - pusr enthusiasts ## Why This Product - Trusted pusr brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Seamless Connectivity:** Experience effortless data transmission with RS232, RS485, and RS422 interfaces. - • **Built-In Web Interface:** Manage and monitor your device effortlessly through an intuitive built-in webpage. - • **Versatile Voltage Range:** Power up with a flexible input voltage of 5-36V DC, perfect for diverse applications. - • **Multi-Host Polling Support:** Connect multiple devices simultaneously with robust Modbus multi-host polling capabilities. - • **Enhanced Network Functionality:** Utilize DHCP, DNS, and network printing for a comprehensive networking experience. ## Overview The Double Serial Device RS232 RS485 RS422 Ethernet Server is a cutting-edge solution designed for seamless communication between TCP/UDP data packages and serial interfaces. With support for Modbus multi-host polling, a versatile voltage range, and a user-friendly web interface, this device is perfect for professionals seeking reliable and efficient data management. ## Description USR-N520 is 2-port serial to Ethernet converter. lt adopts Cortex-M7 solution,which has a main frequency up to 400MHz, powerful performance , fast transmission speed, and high reliability. compatible with TCP/P stack, built in hardware and sofware watchdog and a variety of keepalive mechanisms,USR-N520 keeps online all the time. Product Features: lt compatible with TCP Client, TCP Server, UDP Client, UDP Server and HTTPD Client working modes, achieves data transparent transmission via simple configuration. Supports 2 serial ports working independently. Supports 5-36V wide voltage input, with reverse polarity protection. Supports Modbus RTU to Modbus protocol conversion. Supports keepalive mechanism to quickly detect the dead connections and reconnect. Supports hardware watchdog, automatically restarts when the device goes down. Provides remote serial access over the Internet for industrial serial devices. 10/100Mbps Ethernet port and support Auto MDIMDIX. Software selectable RS-232/422/485 3-in-1 serial port(N5X0 models). Rugged metal housing with lP30 protection for wall or optional DIN-Rail mount. Built-in 15KV ESD serial port protection. Supports a wide industrial operating temperature,-40¡æ~85¡æ Flexible serial port data framing setting, which can satisfy user's various demands for data packets segmentation. Versatile operation modes: compatible with TCP Server, TCP Client, UDP, HTTP client, Websocket server. Support virtual COM ,COM Port Redirector USR-VCOM(win¡¤dows). Firmware upgrading via Web Browser and Windows configuration tool Easy-to-use Win¡¤dows configuration tool for auto discovery, multiple device setting and monitoring. Choice of power input: AC-DC adapter(DC Jack) or DC direct(Terminal Block). High security via certificate verification SSL/TLS encryption for secure data transmission,HTTPS,compatible with TCPS,MQTTS. Support modbus RTU master,edge computing, modbus gateway,MQTT gateway. Cloud support: Compatible with MaTT via AWS lOT, Thingsboard, Alibaba Cloud, EMQX, Tuya,Cumulocity loT and so on. Review: Writes log files to your C:Drive and fills it up FAST - Writes useless, garbage log files to your C:Drive every 300 milliseconds and fills it up EXTREMELY fast (in the high hundreds of MB per day). Avoid this product if connected to a network. Review: Nice little device - especially for the price - I had a couple of RS232 only serial Modbus Slave devices, that would not play well with others, even when connected via individual RS232-485 adapters. ie I needed to multidrop them due to a shortage of serial ports on the RTU I was programming, and they would not cooperate. This adapter fills the niche. Setting it up as a Modbus over IP Slave it accepts connections on a couple of user selectable ports, and translates the Modbus over IP commands to Serial Modbus RTU commands and spits them out its ports. Each physical port is uniquely addressable in the format 192.168.50.120:1502 and 192.168.40.120:1503 in my case, and the Serial RTU address can be specified as part of the message, so the end of line slave device doesn't know the difference between this device and a dedicated serial line. I tested powering the unit from USB (USB to barrel connection), but it also has terminals, and I'm using them for a bit more voltage headroom (USB 5V is at the bottom of its acceptable supply range) The web page for setup and the (windows) software you can download seem to duplicate each other - I used the software to set the IP address, then the webpage for subsequent tinkering. There's no diagnostics I can see of for example the message bytes passing through, nor is there a DIN rail mount, but these are small things, especially at this price point. ## Features - The USR-N520 Supports Modbus RTU Master for retrieving field site data from serial meters. After collecting data, users can convert serial data to MQTT json format data, allowing users to get field site data while save space and time. - New Solution: New ARM core, Cor¡¤tex-M7 solution, which has a main frequency up to 400MHz, compatible with TCP/lP protocol stack. lt has low latency and strong scalability, stable and reliable. - USR-N520 compatible with TCP Client, TCP Server, UDP Client, UDP Server and HTTPD Client working modes, achieves data transparent transmission via simple configuration. Supports 2 serial ports working independently. - Modbus Gateway: It compatible with Modbus TCP and Modbus RTU protocol mutual conversion, multi-host poling function. - Dual Sockets: Each serial port supports connecting to two different servers at the same time. Two sockets are mutually backed up, providing higher reliability and better flexibility. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B07G56LBQJ | | Best Sellers Rank | #76 in Computer Networking Device Servers | | Brand | PUSR | | Compatible Devices | PC | | Connector Type | RS485 | | Customer Reviews | 3.2 out of 5 stars 10 Reviews | | Finish | Transparent | | Finish Type | Transparent | | Input Voltage | 36 volts | | Item Dimensions | 8.27 x 5.91 x 1.97 inches | | Item Weight | 0.65 kg | | Item dimensions L x W x H | 8.27 x 5.91 x 1.97 inches | | Manufacturer | PUSR | | Mfr Part Number | USR-N520 | | Model Number | USR-N520 H7 Version | | Number of Items | 1 | | Number of Ports | 2 | | Package Quantity | 1 | | Specific Uses For Product | PC | | UPC | 723980935284 661787210442 740030459477 703063198997 | | Unit Count | 1 Count | | Warranty Description | 1 | ## Images ![Double Serial Device RS232 RS485 RS422 Ethernet Server Modbus to MQTT lot Gateway Multi-Host Polling USR-N520 H7 Version - Image 1](https://m.media-amazon.com/images/I/61oiznPtgoL.jpg) ![Double Serial Device RS232 RS485 RS422 Ethernet Server Modbus to MQTT lot Gateway Multi-Host Polling USR-N520 H7 Version - Image 2](https://m.media-amazon.com/images/I/51W0HCk6GlL.jpg) ![Double Serial Device RS232 RS485 RS422 Ethernet Server Modbus to MQTT lot Gateway Multi-Host Polling USR-N520 H7 Version - Image 3](https://m.media-amazon.com/images/I/61MxOjYalTL.jpg) ![Double Serial Device RS232 RS485 RS422 Ethernet Server Modbus to MQTT lot Gateway Multi-Host Polling USR-N520 H7 Version - Image 4](https://m.media-amazon.com/images/I/71YVH8lMoHL.jpg) ![Double Serial Device RS232 RS485 RS422 Ethernet Server Modbus to MQTT lot Gateway Multi-Host Polling USR-N520 H7 Version - Image 5](https://m.media-amazon.com/images/I/61k6TY1CY+L.jpg) ## Questions & Answers **Q: Does the device come with two DB9 screw termial headers?** A: USR-N520 supports DB9 male port. Not terminal type.Meanwhile, we will provide RS232 to RS485/RS422 convertor. **Q: Is a power supply included in the box?** A: None in my boxes. Can run off 12-24v dc with no problems. **Q: Does it have a filter to ignore lines of data?** A: Not that i know of. **Q: Once this device is configured, can i ssh into it to be able to access either one of the rs-232 ports behind it? (console into 2 network router)** A: USR-N520 does not support SSH, you can access the RS232 port behind it via TCP connection. ## Customer Reviews ### ⭐ Writes log files to your C:Drive and fills it up FAST *by D***M on August 27, 2025* Writes useless, garbage log files to your C:Drive every 300 milliseconds and fills it up EXTREMELY fast (in the high hundreds of MB per day). Avoid this product if connected to a network. ### ⭐⭐⭐⭐⭐ Nice little device - especially for the price *by A***J on July 19, 2018* I had a couple of RS232 only serial Modbus Slave devices, that would not play well with others, even when connected via individual RS232-485 adapters. ie I needed to multidrop them due to a shortage of serial ports on the RTU I was programming, and they would not cooperate. This adapter fills the niche. Setting it up as a Modbus over IP Slave it accepts connections on a couple of user selectable ports, and translates the Modbus over IP commands to Serial Modbus RTU commands and spits them out its ports. Each physical port is uniquely addressable in the format 192.168.50.120:1502 and 192.168.40.120:1503 in my case, and the Serial RTU address can be specified as part of the message, so the end of line slave device doesn't know the difference between this device and a dedicated serial line. I tested powering the unit from USB (USB to barrel connection), but it also has terminals, and I'm using them for a bit more voltage headroom (USB 5V is at the bottom of its acceptable supply range) The web page for setup and the (windows) software you can download seem to duplicate each other - I used the software to set the IP address, then the webpage for subsequent tinkering. There's no diagnostics I can see of for example the message bytes passing through, nor is there a DIN rail mount, but these are small things, especially at this price point. ### ⭐⭐ Has a tendency to need to be power cycled *by Y***L on September 29, 2022* Has a tendency to need to be power cycled. At first I thought it was if it lost power and came up again before the DHCP server could be reached, so I put it on a UPS. No. Then fixed the IP address, again no. Then I thought it was the particular unit, and bought a replacement - still no. It stops working sometimes, and I cannot reach it by IP - and just unplugging power and powering on again, my data stream restarts. I am reading a serial device over telnet every second or a few times a second. --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.ke/products/77775542-double-serial-device-rs232-rs485-rs422-ethernet-server-modbus-to](https://www.desertcart.co.ke/products/77775542-double-serial-device-rs232-rs485-rs422-ethernet-server-modbus-to) --- *Product available on Desertcart Kenya* *Store origin: KE* *Last updated: 2026-09-02*