3G/4G LTE to RS232/RS485/Ethernet/LAN/WAN Industrial M2M Router, USR-G781-AU


Out of stock

SKU: USR0-781Code: USR-G781

US$ 137.41

Out of stock


This is a quality 3G/4G LTE Router from USR. Their products are known for their quality, good documentation and easy to use software.

The USR-G781-AU is an Industrial quality 3G/4G LTE to RS232/RS485/Ethernet Router. This is the Australian version(standard version is USR-G781), using Australian 3G and 4G bands (See "Frequency Band" section below for details). Local devices can be connected to it via RS232/RS485 or Ethernet. For Ethernet, it provides one WAN and one LAN port. It supports VPN(PPTP) clients, and static routing.  This device is very well built, and is supplied in a sturdy metal enclosure. It is manufactured with high quality components, and the latest PCB assembly techniques. 

This product consists of the following:
  1 x Genuine USR-G781
  1 x Magnetic 3G/4G Antenna
  1 x DSub Female to Male Cable
  1 x Australian Wall Mount Power Supply, 5V, 1A, 2.1mm Connector

This popular device is widely used in industrial control, smart electricity, personal health care, smart home to transmit data and other applications.

Operation Frequency Band
        Network TypeG781 (Asia )G781-E (Europe )G781-AU ( Australia )G781-A ( USA )G781-V ( USA )

Additional information is available on USR's product site.

Additional information is available on https://www.usriot.com/products/industrial-4g-lte-modem.html

This product will be shipped via eParcel from Sydney (except if you upgrade to express post during checkout).


  • Australian version with Australian frequency bands.
  • 2 RJ45 port, one can be WAN or LAN port and another one can be LAN port.
  • Support VPN(PPTP) client.
  • Support static routing
  • Support Firewall and QoS
  • Support DDNS
  • Support NTP to check the time.
  • Support TCP/UDP client mode and server mode.
  • Support identity packet and heartbeat packet.
  • Support Serial to HTTP format
  • Support upgrading firmware via FTP.
  • Integrated Hardware and software watchdog timer.


Working Temp-40~85℃
Storage Temp-45~105℃
Working Humidity5%~95%
Storage Humidity5%~95%
Serial PortRS232/RS485
Network ProtocolIPV4, TCP/UDP
IP Access MethodStatic IP, DHCP
DNS, Modbus, Customize WebpageSupport
SIM card&Antenna 
SIM/USIM CardStandard 6 pin SIM card, 3V/1.8V SIM card
Antenna3/4G full-frequency antenna * 1
Wired Ethernet Port 
WAN portWAN *1
LAN portLAN * 1
 Both LAN port and WAN port with a rate of 10/100Mbps,Auto MDI/MDIX
Port Number2 (1*RS-232, 1*RS-485, can not work at the same time)
Interface StandardRS-232: DB9 pin type, RS-485: 2 wire (A+, B-, GND)
Data Bits5, 6, 7, 8
Stop Bit1, 2
Check BitNone, Even, Odd, Space, Mark
Baud Rate300 bps ~ 460800 bps
Flow ControlRTS / CTS
BufferSend and receive 4K bytes respectively
ProtectionRS-485: surge protection, overvoltage protection
RS-485 Pull-up and Pull-down Resistor2.2 KΩ
Power Supply 
Working VoltageDC 5~36 V
Working Current95mA@5V

Quick Start

To configure this device, do the following:

  1. Insert the SIM card, and power the USR-G781
  2. Connect the LAN port on the USR-G781 directly to a PC. Ensure the PC is configured to obtain it's IP address via DHCP(often called "obtain and IP address automatically" in Windows). This is normally the default setting. See Note 1 below.
  3. After a couple of seconds, the PC should get assigned an IP address from the DHCP server running on the USR-G781
  4. In a browser, go to to configure the USR-G781 via it's built in web server.
  5. When asked for username and password, enter "admin" and "admin"

Note 1: During step 2 it might be necessary to disable and enable the Ethernet network of the PC.  On Windows, this is done in the "System Settings"-->"Network & Internet"-->"Change Adapter Options" section. Right click on the "Ethernet" icon to disable and enable it. Resetting the Ethernet adapter might be required because the PC could already have been assigned an IP address by the previous network it was connected to.

Additional Information, Software & Documentation

For additional Information, Software & Documentation, see the product page on USR's website.

  • Datasheet: https://modtronix.com/mx-m/usr/usr-g781_datasheet.pdf
  • User Manual: https://modtronix.com/mx-m/usr/usr-g781_user_manual.pdf

For additional Information, Software & Documentation, see the product page on USR's website:

Typical Applications

  • Smart Grid/Electricity
  • Smart Home
  • Industrial automation and control
  • Personal health care
  • Vending Machines
  • Industrial Machine to Machine (M2M) communication.


Package Includes

  1 x Genuine USR-G781-AU (Australian version) - 3G/4G LTE to RS232/RS485/Ethernet/LAN/WAN Industrial M2M Router
  1 x Magnetic 3G/4G Antenna
  1 x DSub Female to Male Cable
  1 x Australian Wall Mount Power Supply, 5V, 1A, 2.1mm Connector

SKU: USR0-781 Category: Tags: , , , , , , , , ,
Weight700 g

Wireless Technology


Wired Technology

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