Industrial Four Serial RS232/RS485/RS422 to Ethernet Converter Server

Serial Device Server
20-rs485 to ethernet adapter1-ethernet to serial converter
USR-N540/$109.60 In stock


Power: DC 5~36V (adapter and screw terminal)
1)Multiple serial can work as RS232(RXD TXD GND RTS CTS), RS485(A+ B- GND) or RS422(RX+ TX- GND TX+ RX-).
2) 10M/100M Ethernet port(MDI/MDIX).
Certificate: CE, FCC, ROSH, WEEE.

Request a Quote

USR-N540 Industrial Four Serial Device Server RS232/RS485/RS422 to Ethernet Converter for data transparent transmission. It is internally integrated with TCP/IP protocol. User can configure parameter by web server or software to realize remote data acquisition, remote control and management.


  • Modbus Gateway: Modbus RTU to Modbus TCP.
  • Watch Dog: if USR-N540 break down, it will restart.
  • Built in Web Server/Webpage for configuration.
  • User can modify the webpage.
  • Webpage socket to Serial.
  • Various protection: Serial Port, Ethernet Port, Power supply.
  • Support DHCP client: automatically obtain an IP address and query IP address.
  • DNS address can be modified.
  • Synchronous and adaptive Serial port baud rate.
  • HTTP Client: send data as HTTP format automatically.
  • Registration packet: identified header can be added to packets to check connection status.
  • Heartbeat packet: can be sent to serial or network periodic. To ensure connection is reliable, put an end to dead link.


1) Parameter configuration software.
2) Virtual serial port software(VCOM), Windows 2000 or higher (32 bit/64 bit)
Configuration method:
1)Setting Software configuration
2) Web Server configuration: Please input IP: 192.168.07. Name and Password: admin.
3) AT Command Set
Firmware upgrade via network by Setup Software (User Manual)
Factory Setting:
1) Hardware reset: Pull down Reload for 5 -15 seconds, then release it.
2) Software reset: Enter AT command mode, use AT command AT+RELD.

Work Mode
Serial Device Server USR-N540 can work as TCP Client, TCP Server, UDP Client,
UDP Server Mode.
1) In TCP Client Mode: Client connects Server automatically. User should configure the TCP Server’s IP address and Port.
2) In TCP Server Mode: The Max Client number is 8.
3) In UDP Client Mode: serial data will be sent to a fix IP address/port which you appointed.
4) In UDP Server Mode: serial data will be sent to last source IP/Port.


  • Industrial automation control for data transmission.
  • Security monitoring, CCTV, entrance guard system, Building automation system
  • Smart home: smart switch, thermos controller.
  • Environmental monitoring, temperature and humidity monitoring.
  • Logistic transportation supervision and location system.
Basic Information
VoltageDC9 ~ 24 V
Current 95mA (aver) @ 5V
Working Temp-40 ~ 85°C
Storage Temp-40 ~ 105°C, 5 ~ 95% RH
Size222 x 122 x 29 mm
Serial Port
4 ports can work simultaneously in different mode
SignalRS232: TX/RX/RTS/CTS
RS485: A/B/G
RS422: T+/T-/R+/R-
Baud Rate600bps ~ 230.4Kbps
Data Bit5, 6, 7, 8
Stop Bit1, 2
Check BitNone, Even, Odd, Space, Mark
BufferTX: 2K bytes, RX: 2K bytes
Ethernet Port
Speed10/100 Mbps, Auto MDI/MDIX
ProtocolsIP, TCP, UDP, DHCP, DNS, ARP, ICMP, Websocket, HTTP Client, Modbus TCP
BufferTX: 16K bytes. RX: 16K bytes
RS232/ RS485/ RS422 Port2KV ESD protection
Ethernet Port 1.5KV electrical isolation
Power protectionReverse protection, ESD protection, Surge protection
Accessory12V1A Power Supply, Serial Cable
Warranty2 Years

User Manual

[Datasheet] USR-N540 Datasheet | download
[User Manual] USR-N540 Quick Start Guide | download
[User Manual] USR-N540 User Manual | download>
[AT Command] USR-N540 AT Command Set | download

Development File

[Customized Webpage] USR-N540 Customized Webpage | download
[Demo Code] TCPIP Demo Code | download
[Config Protocol] E45&M4 Series Config Protocol V1.4 | download

Application Software

[USR-VCOM] Virtual Serial Software V3.7.1.520 | download
[USR-TCP-Test] Testing Software | download
[USR-TCP-Test_android] Testing Software | download
[USR-M4] USR-TCP232-M4K3 Setup Software | download

Product Certificate

[Certificate] M4 Series CE FCC ROHS WEEE Certificate | download

Company File

[Product Catalog] USR Product Catalog | download


All USR products will be tested by R&D first, then production test again.(ESD Test,Surge/EFT Test, High/Low Temperature Test, EMC and LVD environment reliability test, etc.) Click here to watch test videos.
USR products test USR products test USR products test USR products test
USR products are exported to more than 100 countries and regions, get approvals like CE, FCC, ROHS, CCC, KC, IC, SRRC, etc.
USR product certificate
We also offer fast and reliable After-Sales Service, Leave your questions in Ticket System and we will respond to you in 15 minutes.
Get a FREE quote today and join the growing community of “IOT” dealers
© 2017 USRIOT All Rights Reserved    xml sitemap