Leading Edge Networking Solutions


4-Port Industrial Secure Modbus TCP/RTU/ASCII Gateway, DIN-rail mount, wide-temperature


Diverse Hardware Infrastructure
Modbus Gateway supports the four most commonly used communication standards, RS-232/485/422, and Ethernet. The ease-ofuse configuration utility provided with Modbus Gateway can quickly select the hardware interface , and easily switch to the existing communication infrastructure. Industrial EMC protection and wide temperature operation capability make MB5904D ready for every mission.

Embedded Security
MB5904D Modbus Gateway supports IPsec VPN encryption, allowing you to safely use the device over the internet without worrying about malicious attacks, data sniffing or unintentional remote control of your Modbus slaves. The embedded VPN deamon supports peer-to-peer and peer-to-side connections.

Switching between Modbus Protocols
Modbus Gateway supports the standard Modbus protocol and is capable of converting any Modbus protocols between Modbus TCP, Modbus RTU, and Modbus ASCII for all supported hardware interfaces.

Modbus ID Routing
Modbus Gateway supports various types of hardware communication interfaces, Modbus protocol conversion, and Modbus ID routing. Therefore the Modbus Gateway can integrate your existing and complex Modbus hardware configuration into a simple network that can be easily managed.


  • Bi-Directional Modbus TCP/RTU/ASCII conversion from Serial to Ethernet and Vice-versa
  • Industrial-grade hardware for operating in harsh environments
  • Wide temperature range for operations at extreme temperatures
  • Advanced features include embedded IPsec VPN security, Virtual ID remapping, VirtualCOM mode, exception handling and many others
  • 2 x 10/100/1000Mbps Ethernet port,
  • 4 x RS-232/422/485 port, up to 921.6 Kbps
  • Configuration via Web Browser / Serial-Telnet Console / Windows Utility
  • Rugged metal case with wall or DIN-Rail mount

ModbusTCP Logo

MB5901 application  MB5904D Series

MB5904D-4P-DB - 4x RS232/422/485 (DB9M)+ 2x 10/100Base-TX (RJ45)

MB5904D-4P-TB - 4x RS232/422/485 (TB)+ 2x 10/100Base-TX (RJ45)

MB5904D-4P-G-DB - 4x RS232/422/485 (DB9M)+ 2x 100/1000 Base-X (SFP)

MB5904-4P-G-TB - 1x RS232/422/485 (TB)+ 2x 100/1000 Base-X (SFP)

Serial RS232

  • Serial Baud Rate: 1200 bps to 921 Kbps
  • Data Bits: 7, 8
  • Parity: odd, even, none, mark, space
  • Stop Bits: 1, 2
  • Signals: TxD, RxD, RTS, CTS, DTR, DSR, DCD, RI, GND
  • flow Control: XON/XOFF, RTS/CTS, DTR/DSR


  • 9~48 VDC power input at 3-pin terminal block
  • Overload Current Protection Present

Operating Temperature: -40 to 85°C
Operating Humidity 5% to 95% Non-condensing

Warranty 5 years


MDR-45 series DIN-Rail power supply


  • Protocols: IPv4, ICMP, TCP, UDP, DHCP Client, SNMPv1,v2c,v3, HTTP, HTTPS, Telnet, RFC2217, RSTP, Security via OpenVPN Client/Server or IPsec VPN (peer-to-peer or peer-to-side) with up to 37.9Mbps VPN throughput, PPTP, and SMTP/TLS
  • Management: Web, Device Management Utility, Telnet, SNMPv1/v2c/v3, SMS
  • Virtual COM: Windows/Linux redirection software
  • Modbus Gateway Supported Modes: Ethernet: Modbus TCP Server/Client(or VCOM); Serial: Modbus RTU/ASCII (master/slave)
  • Maximum number of Modbus clients/slaves: Modbus TCP: Maximum 16 clients; Maximum 32 slave connections