GPRS module , the embedded version of GPRS DTU , is small in size and easy to integrate into other devices. Its function is similar to that of a serial port server .
The GPRS module is an Internet of Things wireless data terminal that uses the public operator network GPRS network (also known as the G network) to provide users with wireless long-distance data transmission functions. It uses high-performance industrial-grade 8/16/32-bit communication processors and industrial-grade wireless modules, uses an embedded real-time operating system as the software support platform, and provides RS232 and RS485 interfaces, which can directly connect to serial devices to achieve transparent data transmission. Function.
GPRS module working principle
The communication between the GPRS module and the server is initiated by the GPRS module end (client), and the server end responds to the module end by sending feedback or accepting communication. The module side and the server side together form an application system based on GPRS and INTERNET network communication. Compared with the module side, the server side is installed with more complex applications, which can accept communication requests initiated by any module side and detect the communication status in the link at all times, thereby realizing real-time data collection, database services and other applications.
The module side needs to know the IP address and port number of the server side in advance before it can initiate a communication request. Once communication is established, there is no difference between the server side and the module side.
L'indirizzo IP del server può essere un IP pubblico (IP fisso) o un nome di dominio dinamico ottenuto tramite un server di risoluzione dei nomi di dominio.
The port number of the server usually corresponds to the specific application running in the server, such as port number TCP 21 is used by the FTP service and TCP 80 is used by the Hypertext Server (HTTP). That is, the server-side application supports sending and receiving data through a specific port number.
The communication and protocol conversion process between the GPRS module side and the server side is shown in the schematic diagram below:
Usually the IP address obtained by the GPRS module is its intranet IP address randomly assigned by the GSM network operator. It can access the Internet through the mobile operator’s gateway. Special attention should be paid to the NAT (network) provided by the mobile GPRS gateway during system application. Address translation) port mapping service has a very short validity period, so if you need to maintain two-way communication, you must set up heartbeat packets sent regularly by the GPRS module to maintain NAT port mapping.
Features of Zongheng Intelligent Control GPRS module:
●Connection method: Support GPRS and GSM
●Transmission mode: fully transparent data transmission, transparent data transmission with ID
●Transmission protocol: Support TCP, UDP
● Data center: Supports dynamic domain name and fixed IP address access
● Stable: supports automatic heartbeat and remains permanently online; dual watchdog design, never downtime
● Efficient: 100K large cache
● Flexible: small size, simple and convenient docking, and can be integrated into other devices
● Manageable: The module can be remotely configured and queried through the web page
● Easy maintenance: supports remote firmware upgrade