Agricultural well irrigation control system
Communication mode selection
At present, the communication modes of underwater automatic monitoring system at home and abroad mainly include ultrashort wave, short message, PSTN fixed telephone and GPRS wireless data transmission mode. All kinds of communication methods have their advantages and disadvantages. This system uses GPRS communication mode as main channel and GSM short message communication as auxiliary channel networking mode.
The monitoring station uses self reporting, self reporting and confirming working system to collect water level data. Usually the monitoring data acquisition terminal station in micro power duty state, GPRS communication terminal, the water level sensor in the power-off state, when the set time (1 hours) will automatically enter the working state data acquisition terminal monitoring station, and turn the power GPRS communication terminal, water level sensor, water level sensor monitoring station for stable work after the water level data acquisition and the data recording and timing write memory, if the condition is satisfied to send data, monitoring station to initiate GPRS dialing, establish a PPP connection monitoring station registration, and then send the collected data of water level.
system function
The system is a real-time operation system for data acquisition, storage, transmission and processing of water level / depth data, and has real-time data query, statistics, analysis, and graphical representation of the results. After the completion of the system, the following functions can be realized:
1) system working standard: self reporting, self reporting, confirming, answering, working system networking.
2) system communication uses GPRS dual mode to send data to the center.
4) all stations are more than 256K of memory recording and automatic power-off data protection function. Via a laptop or PDA portable equipment monitoring station for several days or read daily recording data in the field. The center can be read from the newspaper / response monitoring station or single day for several days recording data through the GPRS network.
6) system can timely understand the monitoring center station of the working state of the equipment (such as voltage, automatic memory etc.).
7) the system real-time data can be automatically written into the information database of groundwater automatic monitoring system, and the monitoring data can be browsed by the relevant departments through the computer wide area network, and the data sharing can be realized by WEB;
8) the sending data of the monitoring station can be set up as a self reported, self reported and confirmed working mode, and the data retransmission can be realized.
9) the system center has the functions of data storage, statistics, report display and printing and process analysis, such as dynamic water level / depth display, etc..
10) require data acquisition equipment with micro power consumption and data acquisition / transmission control function, reduce equipment and operating costs. The system has the dynamic control mechanism of collecting data density, so as to maximize the communication cost and power consumption under the condition of meeting the data density and precision requirements.
11) the working parameters of the monitoring station can be configured in the field with a portable computer.
14) the system is scalable and can easily increase and decrease the number of stations and the number of sensors. The modification work will be operated by password management, and the system database management function will be realized.
Characteristics of monitoring station
1) data acquisition and communication strategy control
The data acquisition strategy of each sensor can be established, such as the acquisition cycle, encryption cycle, threshold control, etc., to control the density of data communication.
2) monitoring power consumption control mechanism
The unique soft and hard power down technology greatly reduces the power consumption of the monitoring station, and prolongs the service life of the sensor, communication equipment and battery.
3) battery charging and discharging protection mechanism
Integrated battery charging and discharging function can avoid battery damage and greatly reduce the cost of operation and maintenance in the future.
4) the communication mechanism of self reporting, self reporting confirmation and central calling
By setting parameters to select the monitoring station to work in different communication modes, the monitoring system can achieve a good balance between communication efficiency and communication reliability.
5) data recording
Provide backup of monitoring data, make the monitoring system meet the different needs of groundwater resources monitoring and groundwater resources data reorganization, and further improve the reliability of monitoring data.
System technical index
The system can complete the collection, processing and forwarding of the whole system real time data in 5 minutes.
The system operates at low power consumption, and the solar cell configuration has the capability of resisting continuous rain for more than 20 days.
The error rate of data transmission channel is less than 1 x 10-5.
The average patency rate of the system is greater than or equal to 99%.
Data accuracy: water meter resolution meets the full range of + 2.5 per 1000.
Monitoring station composition
Automatic monitoring station is an important part of water resources monitoring system, the station should be automatic real-time acquisition and storage level / depth data is sent to the two grade center through the communication network. The station is generally composed of water level sensor, data acquisition device, communication system equipment and power supply unit.
The composition of self reporting / answering monitoring station
This system in the extension of the 40 stations are all self reporting / response monitoring station, self report / response monitoring station by monitoring terminal (RTU with the GPRS communication module, 10AH lithium batteries), 5W solar battery board, a bracket and a float type water level gauge, cable protection box (or real observation wells etc).
Composition form of self reporting / answering type monitoring station
Telemetry terminal
YD-1003 type automatic telemetering terminal for water level
For the water / liquid level monitoring terminal YD-1003 type water level automatic monitoring, data acquisition, storage and transmission function, the integrated structure, has the characteristics of small volume, convenient installation, stable performance, simple operation, low cost, outstanding, is a very suitable for the national conditions of our country, the automatic monitoring system of water resources of the terminal products with water high price.
Model: YD-1003
Size: size (length, width, width, height, height): 220 x 90 x 41 (mm)
Weight: less than 250g (without antenna).
major function
1, access to RS485, analog (4~20mA), intelligent sensors (SDI-12 protocol);
2. It has large capacity FLSH storage. It can automatically store, recycle storage and start / stop storage function at a preset threshold
For example, from a certain time (such as the flood season began) to start recording function, recording function at a certain moment closure (such as the end of the rainy season);
3, with GPRS/CDMA/SMS and other communication methods
4, support self reported, self reported, confirmed, response mode of work;
5, support power down, standby, permanent online mode;
6, support remote wakeup, response center command. In the monitoring station on standby, ready to wake up center testing station for data collection, read or modify any time automatic monitoring station configuration information etc.;
Technical advantages:
7, integrated structure, small size, simple structure, user-friendly design, easy to operate, free maintenance;
8, micro power consumption, in the absence of sunlight or solar panels damage, can work for 2 months;
9, large capacity FLSH memory, support rewritable;
10 、 bidirectional communication under low power consumption mode;
11 、 real time and historical data calculation function;
12. All interfaces have photoelectric isolation or surge protection circuit.
WFX-40 series mechanical coding water level sensor
Characteristics and uses
The special anti skidding machine for measuring cable can be used in any wind and wave environment.
This series of instruments are designed and manufactured according to the national standard GB/T11828.1-2002. The instrument level rate, surge serious environment, with good accuracy and stability, especially suitable for hydrological station and reservoir station, dam station, hydropower station, remote station use.
This series of equipment by the absolute value of encoding type water level sensor, float, suspension, counterweight and other components, is independent of the water level observation and measurement instrument, and can display, gate opening device, gate hoist control system is connected, composed of computer integrated display and control system (such as locks, hydropower stations, pumping pumped storage power station, agricultural irrigation system, water supply and drainage system); water level configuration of RS485 communication interface device, can directly communicate with the computer machine, network composed of hydrological automatic monitoring system, hydrological satellite telemetry system; configuration storage recording unit can be widely used in hydrological station.
This series of instruments is suitable for use in fine wells and general logging with a diameter of 25 cm to 30 centimeters.
Three. Technical parameters
Measuring range: 10M, 20m, 40m, 80m
Resolution: 1cm
And the measurement accuracy: less than 2cm or 0.2%F - S
- output code: 10 ~ 13bit gray
Field monitor: decimal mechanical counter
Data output interface (option): built in serial RS485 interface;
Built in 4-20mA analog output
Power supply voltage: 12 ~ 24V DC
Float diameter: 150mm, 100mm
Measuring cables: 1mm multicore stainless steel cables
Use environment: ambient temperature: -25 ~ 85 c;
Relative humidity: <90% (40)
Size: 132 x 132 x 115mm
