Agricultural well irrigation control system
Communication mode selection
At present, the communication modes of underwater automatic monitoring system at home and abroad γmainly include ultrashort wave, short message, PSTN fixed telephone and GPRS wireless data tran×smission mode. All kinds of communication methods ha¥ve their advantages and disadvantages. This system uses GPRS communication mode as main channel£ and GSM short message communication as auxiliary channel networking mode.λ
The monitoring station uses self reporting, self reporting and confirming working £system to collect water level data. Usually the monitoring data acquisition termin∑al station in micro power duty state, GPRS communication terminal, the water level sensor in λthe power-off state, when the set time (1 hours) will automatically enter the working s↑tate data acquisition terminal monitoring station, and turn the power GPRS communication tδerminal, water level sensor, water level sensor monitoring ™station for stable work after the water level data acquisition and the d←ata recording and timing write memory, if the condition is satisfied ∏to send data, monitoring station to initiate GPRS diali<ng, establish a PPP connection monitoring station registration, and then send the collected datβa of water level.
system function
The system is a real-time operation system for data acquisition, storage, transmission and proces₽sing of water level / depth data, and has real-time data query, stati stics, analysis, and graphical representation of the results. Afte✔r the completion of the system, the following functions can be realized:
1) system working standard: self reporting, self reporting, confirming, answering, work★ing system networking.
2) system communication uses GPRS dual mode to send data to the cen≤ter.
4) all stations are more than 256K of memory recor↑ding and automatic power-off data protection function. Via a laptop or PDA λportable 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 net work.
6) system can timely understand the monitoring center station o$f 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 gro×undwater automatic monitoring system, and the monitoring data can be browsed by the rel&evant 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 u↓p 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 storaΩge, statistics, report display and printing and process analysis, such as dynamic water level / depεth 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 maximi↓ze 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 c¶onfigured in the field with a portable computer.
14) the system is scalable and can easily increase and decrease the number of stations and the nu<mber of sensors. The modification work will be operated by password management, and the s₽ystem 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 ac≤quisition cycle, encryption cycle, threshold control, etc., to control the de←nsity of data communication.
2) monitoring power consumption control mechanism
The unique soft and hard power down technology greatly reσduces the power consumption of the monitoring station,& and prolongs the service life of the sensor, communication equi✘pment and battery.
3) battery charging and discharging protection mechan€ism
Integrated battery charging and discharging function can avoid battery damage and gr≥eatly reduce the cost of operation and maintenance in the future.
4) the communication mechanism of self reporting, self reporting confirmation and πcentral calling
By setting parameters to select the monitoring station to work in different communication modes, t•he monitoring system can achieve a good balance between com'munication 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 groundwate≥r resources data reorganization, and further improve the reliability of monitoring data.
System technical index
The system can complete the collection, processing and for₽warding of the whole system real time data in 5 minutes.
The system operates at low power consumption, and the solar cell configuration has the ca∞pability of resisting continuous rain for more than 20 days.
The error rate of data transmission channel is less thσan 1 x 10-5.
The average patency rate of the system is greater tεhan 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 acqui✔sition and storage level / depth data is sent to the two grade center through the communicatio£n network. The station is generally composed of water level sensor, data acquisition device, comm∏unication 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 monitorin×g terminal (RTU with the GPRS communication module, 10AH lithium batte♦ries), 5W solar battery board, a bracket and a float type water level gauge, cable pεrotection box (or real observation wells etc).
Composition form of self reporting / answering typ✘e 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, dat¥a acquisition, storage and transmission function, the integrated structure, ha♦s the characteristics of small volume, convenient installation, sta♠ble performance, simple operation, low cost, outstanding, is a very suiΩtable for the national conditions of our country, the aut®omatic monitoring system of water resources of the te★rminal 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 b∞egan) 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, πeasy to operate, free maintenance;
8, micro power consumption, in the absence of sunlight or sol←ar panels damage, can work for 2 months;
9, large capacity FLSH memory, support rewritable;
10 、 bidirectional communication under low power consumpti←on 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 anβd wave environment.
This series of instruments are designed and manufact£ured according to the national standard GB/T11828.1-2002. The instrument levεel rate, surge serious environment, with good accuracy and stability, especially suitable☆ for hydrological station and reservoir station, dam station, hydropower stati↔on, remote station use.
This series of equipment by the absolute value of encoding type water l∑evel sensor, float, suspension, counterweight and other compo≈nents, 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 an♠d 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 diame↕ter 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
