System Overview In the waterworks, sewage treatment plants, paper mills and water quality monitoring, hydrological monitoring, environmental protection and other industries, some parameters of water quality need to be monitored. The most important and most effective monitoring parameter is the PH value of water.
These parameters need to be timed and even collected and monitored in real time on a daily basis. In the traditional case, artificial field acquisition and laying lines are generally used for acquisition. The former has high collection cost, long acquisition cycle, and large random error, which is not conducive to real-time monitoring. Distance advances, fewer monitoring points, and high wiring costs.
Using the GPRS network's wide coverage, low usage cost, and good data transmission quality, we launched a centralized real-time monitoring system based on GPRS (CDMA, GSM). In the management center, the data of each collection point of the whole plant is monitored centrally, and solar battery power can be used to monitor the water quality of rivers and lakes in real time.
The system has the characteristics of wide collection range, timely collection of data, low system cost and low usage cost, and has great value in hydrological monitoring and environmental monitoring.
System Structure The major structure of this system is the C/S mode. In the management center is a TCP/IP server. All monitoring points are configured to set the PH value acquisition equipment, ie, the PH meter, and configure the wireless transmission equipment, ie, the wireless data terminal. There can be more than one monitoring point, and each monitoring point can be distributed in different places, even across the country. The wireless data terminal of each monitoring point is connected to the server of the management center through TCP/IP, and the terminal is a TCP/IP client. The whole system is a point-to-point TCP/IP communication system. The collected PH value data is sent directly to the computer in the management center, facilitating data storage and analysis.
The block diagram of the system is shown in Figure 1.
The PH meter in the figure is placed in each monitoring point that needs to be monitored. Each PH meter is connected to a wireless collection terminal through a serial port. The collection terminal accesses the Internet through the GPRS wireless network and transmits the data to the management center through the Internet.
The computer of the management center is connected to the Internet through ADSL, dial-up, and broadband, and receives the PH data transmitted by the terminal. Multiple collection terminals use a management center, and data is transmitted to the management center. In the management center can be set up sub-management center, sub-management center can also receive the terminal's data, but the permissions are not the same, the management center can receive all the terminal data, and sub-management center can only receive their own authority to manage the data of the terminal.
System Function The wireless PH centralized monitoring system has the following functions:
ï¬ Centralized monitoring of data from multiple monitoring points, with unlimited monitoring distances;
ï¬ The collection interval of data in the management center can be set remotely.
ï¬ PH meter can be grading, sub-authority management, this level can only manage the ph meter;
ï¬ All-weather, 24-hour online data monitoring;
ï¬ The system is easy to use, and the operation and maintenance costs are low;
ï¬ The system can be expanded arbitrarily, can be arbitrarily reduced, and no investment is wasted;
ï¬ PH value can be set multi-level alarm, alarm time recovery time can record, query;
ï¬ PH data chart analysis, printing, reports and other functions;
ï¬ The collected data can be uploaded to the management center in real time;
ï¬ The collected data can be stored locally on the terminal. Each terminal can store data for about 1 month.
The equipment used by the system equipment system includes a wireless acquisition terminal and a PH meter, and a central management software.
The performance parameters of the wireless collection terminal are as follows.
Hardware features provide an RS-232 serial user interface: TXD, RXD, GND, VCC;
User interface baud rate: 19200 bps;
Provides two status input interfaces and two control output interfaces;
3 indicators: module status indicator, network status indicator, parameter setting indicator;
User interface supports TTL level and RS-232 level (optional);
Use a dedicated power supply voltage regulator module to power the system, improving system reliability;
Power supply and serial port surge protection design;
Program download update;
Plug and play, free setup.
The main device processor, high-speed dedicated MCU;
Data Memory, 32K +512KBytes;
Program Memory, 64K Bytes;
Connector, hole type DB-9;
Wireless module
Hardware interface
DB9 serial data interface definition
Electrical Characteristics ï¬ Power Supply: DC +6V~+36V
ï¬ Average working current: < 450mA
ï¬ Working temperature: -25°C～+60°C;
ï¬ Storage temperature: -25°C～+85°C;
ï¬ working humidity: 5% to 95%;
ï¬
System quotation:
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