As the main facility of water conservancy construction and management projects, the pumping station is responsible for the important tasks of urban drainage and waterlogging prevention and water diversion. Since the 1990s, with the advancement of IT technology and the vigorous development of water conservancy, the automation level of pumping stations in the water conservancy industry has been continuously improved. The pump station technology and management level has been greatly improved, and it has been developed to the monitoring and management of unmanned pump stations abroad, and the results of reducing people and increasing efficiency have been remarkable. In this process, the computer monitoring system of the pumping station plays a vital role. The modern monitoring system can realize the functions of centralized data monitoring of the whole pumping station, automatic control of main and auxiliary equipment, remote control and remote adjustment, and remote transmission of information. It is a reliable guarantee for the safe, reliable and economic operation of the pumping station.

With the help of brand new information technology, the water conservancy automation system has entered a brand new development stage both in structure and function. Water conservancy automation needs to adapt to the new market situation and develop into a comprehensive system integrating computer, control, communication, network and power electronics. It has a leading hardware structure, an open software platform and a powerful application system to ensure that the pumping station can be automatically operated 24/7 and can easily meet the needs of future business development.

The pumping station automation solution based on NA series PLC has become one of the products of choice for the computer monitoring system of pumping stations in the water conservancy industry.

How to build a computer monitoring system with a powerful PLC?

At present, the pump station computer monitoring system adopts an open layered distributed network structure, which is composed of the station control level and the local control unit. Most system-level devices use general-purpose network devices such as Ethernet or FDDI, which are connected to high-performance computers, workstations, and servers. At the site of the controlled equipment, PLC or intelligent local control unit is mostly used. Then it connects with the basic layer of intelligent I/O equipment, intelligent instrument, remote I/O, etc. through the field bus to form the local control subsystem, which is combined with the plant-level system to form the entire control system.

With the expansion of functions and technologies such as safety production and computer technology, the computer monitoring system has also put forward higher requirements for the ability of the local control subsystem core controller. In the choice of the local control level core controller, the powerful PLC has become the first choice of most systems. There are various problems with the foreign general-purpose PLCs currently in common use. If there is no special SOE module. It is simple to open the loop, easy to misoperation under strong interference; poor communication expansion ability. The debugging process is not convenient and intuitive. Therefore, a new generation of PLC must take into account the characteristics of the industry, and can have more powerful functions than foreign general-purpose PLC.

Overall, the computer monitoring system of the pumping station needs PLC to have strong reliability, professionalism, and scalability, so as to ensure that the investment in the computer monitoring system of the water conservancy industry can not only meet the actual and future needs, but also the investment can be fully protected. The solution based on NA400 PLC makes hydropower plant automation more powerful and reliable. NA400 intelligent programmable controller is an important member of NA series intelligent programmable controller family. In the development and development process, it adopted a series of latest achievements and latest ideas in the field of industrial control, summed up the success of foreign PLCs, aimed at the latest development trend of PLCs, and adopted advanced production and processing technology and refined appearance design in the production process . I believe it will bring you a refreshing feeling.

The main features of NA400 are as follows:

■High-performance monitoring (CPU) module The CPU module uses embedded technology that conforms to the international standard IEEE P996.1, Pentium level, and the main frequency is above 300MHz. Large-capacity electronic hard disk and memory. The software uses a real-time multi-task embedded operating system. The high-end hardware and software configuration makes the CPU module have powerful data processing capabilities, computing capabilities, and communication processing capabilities, which can significantly improve the intelligence.

■Fully intelligent I/O modules All I/O modules are intelligent. In addition to completing the data collection task, it can process the collected data. At the same time, it has a self-diagnosis function to ensure more stable operation in the harsh environment of the industrial site. It can also better avoid the influence of some interference signals on data collection.

■The open and standard communication network provides 10M/100M Ethernet interface and supports Modbus/TCP protocol. Multiple sets of PLC and monitoring software and host computer system can form a plant-level local area network.

■Powerful serial communication function Serial communication module provides 4 standard RS-485 communication interfaces, each serial port supports programmable mode.

■The advanced fieldbus network internal communication uses CANbus fieldbus, which has fast communication rate, strong anti-interference ability and easy expansion.

■Flexible and reliable dual-machine hot backup redundancy solution. Support dual CPU module, dual Ethernet, dual hot standby redundancy scheme, real-time backup data, more reliable control. No need to compile any program, maintenance-free.

■The convenient and practical local human-machine interface provides a serial communication interface with the touch screen and supports Modbus communication protocol. It can be directly connected with a variety of touch screens without adding auxiliary equipment or writing communication drivers, which is very simple to implement.

■Flexible module configuration I/O module, CPU module and power module can be installed at any position on the bottom plate. In the case of dual-machine configuration, the CPU module can be installed on different backplanes, making the application more flexible, convenient and reliable.

Economic and flexible system configuration The NA400 intelligent programmable controller provides an economical and practical system configuration solution, which is mainly reflected in:

▲The expansion I/O module does not need to be equipped with a special expansion module, only the expansion cable needs to be connected to the expansion backplane, which reduces the system cost.

▲The powerful CPU module provides an Ethernet interface, which saves users the expense of the Ethernet module.

▲The serial communication module provides 8-channel standard RS232/RS485 interface, which can be easily expanded and has more powerful functions, which greatly reduces the cost of communicating with on-site intelligent equipment.

▲In the dual-CPU hot standby redundant system, there is no need to pay for the software and hardware overheads like hot standby modules, making the system more reliable and economical to configure.

▲Output code lock technology The switch output module adopts output code lock technology to ensure that the control output will not be mistaken or rejected.

▲SOE event sequence recording provides SOE event sequence recording function with a resolution of 1 ms.

▲The GPS standard clock interface has a GPS standard clock interface, no setting and no programming is required, and the device can be directly timed.

Friendly interface and powerful programming software NAPro. In addition to supporting traditional programming methods such as ladder diagrams, instruction lists, and structured texts, the software also supports visual programming language-sequence chart programming. And programs written in different languages can call each other. Especially with sequence chart programming, even beginners who have no programming experience or have never learned other programming languages can easily master it.

　Sequence chart

　　Programming language

Now, the computer monitoring system based on the NA400 series PLC provides a flexible, powerful and reliable computer monitoring system for the pumping station. The system has complete functions and a high degree of standardization of software and hardware, which meets the requirements of "unattended" (less on duty) of pumping stations. Realization of downsizing and efficiency gains has achieved good results and can be widely used in various large, medium and small water conservancy automation projects.