DinBox GPRS, upgrading non-IP enabled meter or industrial PC parks to GPRS

The DinBox GPRS is a DIN-rail housed, industrial GPRS modem with pocket size dimensions. 

The modem firmware allows the modem to be connected serially by RS-232 with a non-IP enabled (electricity) meter and to communicate with the host system by IP number and port number, using GPRS, without disturbing the transparent communication between the meter and the host.
This is very useful when upgrading non-IP enabled meter or industrial PC parks to IP without having to change the existing application!

The DinBox GPRS is a serial V.24/RS-232 DIN-rail Quadband (800/900/1800/1900 MHz) GSM and EGSM/GPRS modem for M²M applications with Sierra Wireless (Wavecom) technology inside. 

A GPRS connection can normally only be used if the DTE (e.g. an electricity meter) has TCP/IP capability to create and send PPP packages. Thanks to the embedded TCP/IP stack and the specific modem firmware in Open AT the DinBox GPRS is capable of opening/closing and maintaining a GPRS connection completely independent from the DTE. Once it has opened a GPRS connection the DTE can transmit and receive transparent ASCII data with a host system.

The DinBox GPRS is very usefull when upgrading existing meter or industrial PC parks to IP without having to change the existing application!

The Sierra Wireless (former Wavecom) CPU supports a powerful software development environment - Open AT -, which allows embedded ANSI C applications to be executed directly on the Wireless CPU.
Basically Open AT provides wireless services and TCP / IP connectivity and gives access to hardware resources for which the developer would otherwise need an extra processor.

Bausch Datacom implemented for instance a 'GPRS-ready' Open AT application in the Sierra Wireless (Wavecom) Q24PL CPU of the DinBox GSM/GPRS, allowing 3 remotely switchable working modes: CSD mode (modem acts as a GSM data modem), GPRS mode (modem can receive APN GPRS parameters by SMS) and Socket Serv mode (the modem is in a constant TCP socket listen mode after receiving a SMS and then acts as a socket server).
 

The CSD Data Mode offers a transparant serial communication over GSM. Once the DinBox GPRS is dialed in by the host infrastructure, an unsollicited 'CONNECT 9600 bps' is sent by the DinBox GPRS to the connected meter or PC. Once the transparent communication is set up, the host infrastructure can communicate with the meter or (industrial) PC.

The Socket Server Mode goes a step further. This mode makes it possible to set up and maintain a transparent communication between host infrastructure and meter (or industrial PC) using GPRS TCP/IP communication! The TCP/IP stack in the DinBox GPRS and the Open AT application make this happen.
The DinBox GPRS is in a constant socket server listening mode (to the APN). When a socket client connects to the DinBox GPRS IP number and port, an unsollicited 'CONNECT 9600 bps' is sent by the DinBox GPRS to the connected meter or PC, emulating a GSM data connection (CSD) between modem and meter or PLC. Once the transparent communication is set up, the host infrastructure can communicate with the meter or (industrial) PC over GPRS and IP.

 

In GPRS Mode, the modem has received APN GPRS parameters through SMS. APN server name, user name, password and DNS are entered but there is no GPRS attachment or APN connection.  This mode is to allow DOTA (Download Over the Air) via a FTP host.