Serial to GPRS Gateway

What is a GPRS Serial Gateway Modem? It's an industrial modem with RS232/RS485/TTL interface for wireless M2M solutions. We call it DTU in China, and actually it's a GSM/GPRS RS232/RS485 to Cellular Gateway IP modem. Short name for Serial GPRS Gateway, or RS232 Serial GPRS Gateway.


The GPRS DTU IP Modem is a GSM cellular modem with transparent transmission feature. Working under GSM/GPRS networks.


The GPRS DTU IP modem is a GSM modem rs232 or rs485 port. Also there is TTL interface embedded version.


2.5G mobile communication technology (GPRS) has become widely used of industrials and utilities in recent years and many customers are seeking reliable, flexible and cost-effective data channel to build their information system. Many applications such as ATM, POS, SCADA and surveillance system will require data channels covered all country; this brings a bright future for GPRS data networks applications.Requirements towards information system are varied because of different features of numerous industrial applications. Mobile telecom service providers are required to provide industrial application solutions not only meeting common specifications and also individual special ones.


D120g GPRS M2M modem enables various kinds of legacy devices with serial port to communicate over GPRS network and the Internet easily and freely. It not only works as a GPRS Modem, but also can construct a smooth "GPRS Data Tunnel" between Host End and Remote End, ensuring an efficient communication for data transmission and remote device management. With 1 selectable RS-232/TTL/485 serial port, D120 GPRS M2M modem is an ideal solution for factory automation, environmental monitoring and remote device management for M2M industry. Meanwhile, it is supplied with simple software interface that streamline application development process, freeing system integrators from dealing with complex communication protocols of GPRS and the Internet. Users do not need to change the existing system, saving cost and time for field maintenance, and making it a perfect solution for data transmission.



What is main differrent between a normal modem and a DTU modem?

1. GSM GPRS DTU modem supports transparent data.

2. GSM GPRS DTU modem supports point-to-point, point-to-multipoint, and centre-to-multipoint.

3. GSM GPRS DTU modem supports Dynamite IP Address Mapping.

4. GSM GPRS DTU modem supports Multi-protocol.

5. GSM GPRS DTU modem can widely be used for Utilities, traffic control, finance
and industry supervision, and other wireless M2M solutions.


Main Feature of GPRS Serial to Cellular Gateway

  • Embedded PPP, TCP/IP stack;
  • Transparent data conversion and transmission;
  • Supports static data service center IP address;
  • Supports DNS and dynamic data service center IP address;
  • Supports GPRS/EDGE/3G customized APN or CDMA VPDN;
  • Supports peer to peer, center to multi-point data transmission;
  • Supports Xmodem protocol and firmware updating;
  • Optimized EMC design;
  • Wide range power input;
  • Smart power management;
  • Power on/off control;
  • Industrial class pluggable terminal block;
  • Standard antenna and SIM interface;
  • Reliable, flexible, easy to use and management;


Enhanced Feature of GPRS Serial to Cellular Gateway


Industrial design for different application environments:

1. Industrial class components
2. Embedded RTOS


Built-in multiple communication protocols:



Multiple operation model:

1. Always online: automatic online while it powered on, automatic redial and keep-alive while the line dropped.
2. Data trigged online
3. Ring and SMS trigged online
4. Online control interface with the connected device
5.GPRS/CDMA and SMS backup and switch
6. Data loop testing


Flexible data communication :

1. Supports TCP/IP Server/Client, UDP/IP, DDP, SMS, AT
2. Self-define transparent or protocol communication
3. Self-define last packet idle interval and MTU
4. Self-define customized data frame separator
5. Self-define re-connecting interval
6. Self-define online report interval
7. Self-define heart-beating data frame



Download - GSM GPRS M2M Modem

D120g Serial GSM GPRS Gateway Use Manual


The difference between DTU IP Modem and normal Modem: Click to download


Catalog - Router Modem AP


Industrial Class Series


SOHO Class Series







Industrial Application

  • 1) Remote Data Monitor and Control;

  • 2) CCTV, security surveillance;
  • 3) Water, gas and oil flow metering and schedule;
  • 4) AMR (automatic meter reading);
  • 5) Power station monitoring and control;
  • 6) Remote POS (point of sale) terminals, ATM,
  • 7) Traffic signals monitor and control, Traffic info guidance;
  • 8) Oil field, weather forecast, environmental protection, street lamp monitoring and control
  • 9) Early Warning of Mountain Torrent;
  • 10) Fleet management;
  • 11) Power distribution network supervision;
  • 12) Central heating system supervision;
  • 13) Weather station data transmission;
  • 14) Hydrologic data acquisition;
  • 15) Vending machine;
  • 16) Telemetry, SCADA;
  • 17) Vehicle logistics and diagnostics controlling;
  • 18) Parking meter and Taxi Monitor;
19) Telecom equipment supervision (Mobile base station, microwave or optical relay station)


Appearance-GSM GPRS M2M Modem
Compliant to GSM phase 2/2+
Quad-band GSM850/900/1800/1900MHz
data transmission, always online, auto redail up, remote wakeup or reboot via phone
Supply voltage range 5 - 25VDC(9V suggest)
Class 4 (2W) for EGSM900
Class 1 (1W) for GSM1800
Support Firmware update for better quality
Dimension: 75*50/72*16mm
Weight: 200g

Dimension: 72*46*14.5mm
weight: 100g
Steel shell: good electromagnetic shield and , heat radiate performance
Electromagnetic Compatible
Electrostatic Discharge (ESD): 3 class
Radiated, radio-frequency, electromagnetic field immunity test: 3 class
Storage Temperature: -40 ~ 85°C
Working Temperature: -30 ~ 75°C
Humidity: 95% (non-condensing)
Product Module Network Power Level Interface Order No.
D120S211 Siemens MC39i 900/1800MHz DC 5V~25V RS-232 DB9  
D120Z111 ZTE ME3006 850/900/1800/1900MHz DC 5V~25V RS-232 DB9  
D120H111 Huawei GTM900 850/900/1800/1900MHz DC 5V~25V RS-232 DB9  
D120C111 Wavecom Q39 850/900/1800/1900MHz DC 5V~25V RS-232 DB9  
D120N111 NEOWAY M580 900/1800MHz DC 5V~25V RS-232 DB9  
D220S213 Siemens MC39i 900/1800MHz DC 5V~25V RS-232 20PIN  
D220Z113 ZTE ME3006 850/900/1800/1900MHz DC 5V~25V RS-232 20PIN  
D220H113 Huawei GTM900 850/900/1800/1900MHz DC 5V~25V RS-232 20PIN  
D220C113 Wavecom Q39 850/900/1800/1900MHz DC 5V~25V RS-232 20PIN  
D820S214 Siemens MC39i 900/1800MHz DC 5V~25V RS-232 26PIN  
D820N114 NEOWAY M580Z 900/1800MHz DC 5V~25V RS-232 26PIN  
D820N214 NEOWAY M580i 900/1800MHz DC 5V~25V RS-232 26PIN  
D820G114 GOSPELL GM602-H 900/1800MHz DC 5V~25V RS-232 26PIN