Remote data acquisition system based on GPRS module is provided through China Mobile’s GPRS wireless communication module wide-area wireless IP network system access, the industrial and civilian real-time transmission of data to the centralized data center monitoring and management of the Internet, in order to achieve remote data collection, transmission, and monitoring equipment are unified management and control.
Currently, remote data acquisition system based on GPRS module has been very widely used for people’s production and life provides a great convenience, in many applications, typical applications include network-based GPRS module hydrological data acquisition system.
Hydrologic data acquisition system is the use of communication technologies such as telemetry and computer control means, automatic real-time collection and transmission system for treating rainfall, water level, flow and other hydrological parameters. The systems often require a large number of water points for real-time monitoring, most need real-time monitoring data sent to the back-end server management center for processing. Hydrologic Remote Data Acquisition System is to provide decision support services for regional flood control and drought important infrastructure, construction of hydrological data acquisition system based on GPRS module networks is necessary and indispensable.
In hydrographic data acquisition system based on GPRS module network, application terminal is mainly used sensors. Because there are many hydrological data, water level, rainfall, flow, evaporation and the like. According to data collected by different types of sensors into level sensor and rain sensor. Hydrological monitoring sensor converts the data into a pulse, the pulse collector collection, after data acquisition, communication with the service center before stored in the terminal subsystem.
In hydrographic data acquisition system based on GPRS module network, there are two main important data transfer process: workstations and concentrator connection establishment process and transmit data acquisition process to the concentrator. Data transmission of the system is important in both data transfer and GPRS module based on the network data transfer carried out, wherein the GPRS module the data transfer of the whole system is the most important process in the most basic data transfer, GPRS network the entire module systems indispensable part.
Workstations and concentrator connection setup process: workstation according to the data transmission protocol, to a certain data transmission frame format of the instructions with a public IP address and port number of the workstation, via the Internet and GPRS module network, transmitted to the concentrator. After concentrator receives instructions, return instructions to the workstation with a SIM card number. Central station after receiving instructions to confirm the machine stored SIM card and SIM card number received is consistent, if consistent with the establishment of a successful connection. Thereafter concentrator can normally send data to the workstation, the workstation can also send various commands to control concentrator and collector. If the station does not send data to the concentrator within a certain time, then the focus will automatically disconnect from the station, the time can be set freely.
Collector transmit data to the concentrator process: acquisition automatically via the serial port, according to user pre-set time interval collection transferred from the sensor to capture rainfall, water level and other signals, data conversion and data supplied by the concentrator after packing concentrator according to the definition of an access point name (APN) to increase the portion of packaged data redundancy code and check code and converted into a signal suitable for network data packets transmitted over a wireless link.