As a key facility in water conservancy construction and management projects, pump stations play a vital role in urban drainage, flood prevention, water diversion, and supply. Since the 1990s, with advancements in IT technology and the vigorous development of the water conservancy sector, the level of automation in pump station operations has steadily improved. This has led to significant enhancements in both pump station technology and management practices, paving the way for the adoption of unmanned monitoring and management systems—technologies that are increasingly being implemented overseas. As a result, these innovations have achieved remarkable outcomes in reducing manpower while boosting efficiency. In this transformative process, pump station computer monitoring systems have become indispensable. Modern monitoring systems now enable comprehensive, centralized data collection across the entire pump station, along with automated control of primary and auxiliary equipment, remote control and adjustment capabilities, and real-time information transmission. These features not only ensure the safe, reliable, and cost-effective operation of pump stations but also serve as a robust safeguard for their optimal performance.

　　Leveraging cutting-edge information technology, the hydraulic automation system has entered a new stage of development—both in terms of its architecture and functionality. To keep pace with evolving market dynamics, hydraulic automation must evolve into an integrated system that combines computer technology, control systems, communications, networking, and power electronics. This advanced system boasts a leading-edge hardware design, an open software platform, and robust application capabilities, ensuring seamless, round-the-clock operation of pump stations while effortlessly meeting the demands of future business growth.

　　The pump station automation solution based on Nanjing University Aoto's NA-series PLC has become one of the top choices for computer monitoring systems in pumping stations within the water conservancy industry.

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

　　Currently, the pump station's computer monitoring system adopts an open, hierarchical, distributed network architecture, consisting of a station control level and local control units. System-level equipment primarily utilizes common networking technologies such as Ethernet or FDDI fiber-optic ring networks, connecting high-performance microcomputers, workstations, and servers. At the field level, where the controlled equipment is located, PLCs or intelligent local control units are more commonly employed. These local units are then linked via fieldbuses to lower-level smart I/O devices, smart instruments, and remote I/O systems, forming the local control subsystem. This subsystem seamlessly integrates with the plant-level system, creating the entire control system.

　　As functions and technologies such as safe production and computer systems continue to expand, the requirements for the core controller capabilities of on-site control subsystems in computer monitoring systems have also become increasingly demanding. When selecting a core controller at the on-site control level, powerful PLCs have become the preferred choice for most systems. However, commonly used general-purpose PLCs from overseas often face various challenges: for instance, they lack dedicated SOE modules; their output circuits are simplistic, making them prone to false operations under strong interference; their communication expansion capabilities are limited; and their debugging processes are inconvenient and lack intuitive interfaces. Therefore, the next-generation PLCs must not only address industry-specific needs but also deliver significantly enhanced functionality compared to conventional foreign-made general-purpose PLCs.

　　Overall, the pump station's computer monitoring system requires a PLC with robust reliability, specialized functionality, and scalability—only then can we ensure that investments in computer monitoring systems within the water resources industry not only meet current and future needs but also remain fully safeguarded. The solution based on the NA400 PLC significantly enhances the automation capabilities of hydropower plants, making them more powerful and dependable. As a key member of Nanda Aoto’s NA series of intelligent programmable controllers, the NA400 leverages cutting-edge advancements and innovative concepts from the industrial control sector. It draws upon the proven strengths of leading international PLC technologies, aligning closely with today’s latest trends in PLC development. Moreover, the production process incorporates state-of-the-art manufacturing techniques and features a meticulously crafted, refined aesthetic design—guaranteeing a truly refreshing experience for you.

　　The NA400's main features are as follows:

　　■ High-performance monitoring (CPU) module: The CPU module employs embedded technology compliant with the international standard IEEE P996.1, featuring a Pentium-class processor with a main frequency of 300 MHz or higher; it also includes a large-capacity solid-state drive and ample memory. The software utilizes a real-time, multitasking embedded operating system. This premium hardware and software configuration equips the CPU module with exceptional data processing, computational, and communication capabilities, significantly enhancing its intelligence.

　　■ Fully Intelligent I/O Modules The I/O modules are fully intelligent—beyond simply completing data acquisition tasks, they can also process the collected data. Additionally, they feature self-diagnostic capabilities, ensuring more stable operation even in the harsh conditions of industrial environments, while effectively minimizing the impact of interfering signals on data collection.

　　■ The open, standardized communication network provides 10M/100M Ethernet interfaces and supports the Modbus/TCP protocol. Multiple PLCs, along with monitoring software and host computer systems, can be integrated to form a plant-level local area network.

　　■ Powerful serial communication functionality: The serial communication module provides 4 standard RS-485 communication interfaces, each serial port supporting programmable settings.

　　■ The advanced fieldbus network utilizes CANbus for internal communication, offering fast data rates, strong interference resistance, and easy scalability.

　　■ Flexible and reliable dual-machine hot-standby redundancy solution supports dual CPU modules, dual Ethernet connections, and a seamless hot-standby setup—enabling real-time data backup for enhanced control reliability. No programming required; maintenance-free operation guaranteed.

　　■ The convenient and practical on-site human-machine interface features a serial communication interface compatible with touch screens, supporting the Modbus communication protocol. It can be directly connected to various touch screens without requiring additional auxiliary devices or the need to develop custom communication drivers—making integration exceptionally straightforward.

　　■ Flexible modular configuration: I/O modules, CPU modules, and power modules can be installed at any position on the backplane. In a dual-unit setup, the CPU modules can even be mounted on separate backplanes, offering greater flexibility, convenience, and reliability in your applications.

　　The economic and flexible system configuration of the NA400 intelligent programmable controller offers a cost-effective and practical system setup solution, primarily demonstrated in:

　　▲The extended I/O module doesn’t require a dedicated expansion module—simply connect the extension cable to the expansion backplane, significantly reducing system costs.

　　▲The powerful CPU module features an Ethernet interface, helping users save on the cost of Ethernet modules.

　　▲The serial communication module features 8 standard RS232/RS485 interfaces and can be easily expanded, offering enhanced functionality while significantly reducing the cost of communicating with field-based smart devices.

　　▲In a dual-CPU hot-standby redundancy system, there’s no need to incur software and hardware costs associated with components like hot-standby modules, making the system more reliable and its configuration more cost-effective.

　　▲ The output module employing password-lock technology ensures that control outputs neither malfunction nor fail to respond, thanks to its advanced password-secured switching mechanism.

　　▲The SOE event sequence recorder provides SOE event sequence recording functionality with a resolution of up to 1 millisecond.

　　▲The GPS standard clock interface features a built-in GPS time source, requiring no setup or programming—simply connect it to your device for accurate time synchronization.

　　NAPro is a user-friendly, yet powerful programming software that supports not only traditional programming methods such as ladder diagrams, instruction lists, and structured text, but also a visual programming language—Sequential Function Chart (SFC) programming. Moreover, programs written in different languages can seamlessly call each other. Notably, SFC programming makes it exceptionally easy for beginners—even those with no prior programming experience or who have never learned another programming language—to quickly get the hang of it.

　Sequence Control Diagram

　　Programming language

　　Currently, the computer monitoring system based on the NA400 series PLC provides pump stations with a flexible, powerful, and reliable solution. The system boasts comprehensive functionality, high levels of software and hardware standardization, and fully meets the requirements for "unmanned operation" (minimal staffing) at pump stations—enabling workforce reduction while boosting efficiency. As a result, it has achieved remarkable success and can now be widely applied to large-, medium-, and small-scale hydraulic automation projects of various types.