Modbus Protocol Research Articles

Proposed Modbus Extension Protocol and Real-Time Communication Timing Requirements for Distributed Embedded Systems

The general evolution of fieldbus systems has been variously affected by both computer electrical engineering and science. First, the main contribution undoubtedly originated from network IT systems, when the Open Systems Interconnection model was presented. This reference model with seven layers was and remains the foundation for the development of numerous advanced communication protocols. In this paper, the conducted research resulted in a major contribution; specifically, it describes the mathematical model for the Modbus protocol and defines the acquisition cycle model that corresponds to incompletely defined protocols in order to provide a timestamp and achieve temporal consistency for proposed Modbus Extension. The derived technical contribution of the authors is to exemplify the functionality of a typical industrial protocol that can be decomposed to improve the performance of data acquisition systems. Research results in this area have significant implications for innovations in industrial automation networking because of increasing distributed installations and Industrial Internet of Things (IIoT) applications.

Securing industrial control systems: Developing a SCADA/IoT test bench and evaluating lightweight cipher performance on hardware simulator

This paper addresses the critical need for enhancing security in Supervisory Control and Data Acquisition (SCADA) networks within Industrial Control Systems (ICSs) to protect the industrial processes from cyber-attacks. The purpose of our work is to propose and evaluate lightweight security measures to safeguard critical infrastructure resources. The scope of our effort involves simulating a secure SCADA/IoT-based hardware test bench for ICSs, utilizing Modbus and MQTT communication protocols. Through case studies in remote servo motor control, water distribution systems, and power system voltage level indicators, vulnerabilities such as Denial of Service (DoS) and Man-in-The-Middle (MiTM) attacks are identified, and security recommendations are provided. To execute our work, we deploy lightweight ciphers such as Prime Counter & Hash Chaining (PCHC) and Ascon algorithm with Compression Rate (ACR) for secure information exchange between the plant floor and the control center. Evaluation of these ciphers on Raspberry Pi focuses on execution speed and memory utilization. Additionally, a comparison with the AGA-12 protocol standard for SCADA networks is conducted to underscore the efficacy of the proposed security measures. Our findings include the identification of SCADA network vulnerabilities and the proposal of lightweight security measures to mitigate risks. Performance evaluation of the proposed ciphers on Raspberry Pi demonstrates their effectiveness, emphasizing the importance of deploying such measures to ensure resilience against cyber threats in SCADA environments.

Research on the key techniques of composite processing of EDM and vibration ultrasonic drilling

PurposeUtilizing electrical discharge machining (EDM) to process micro-holes in superalloys may lead to the formation of remelting layers and micro-cracks on the machined surface. This work proposes a method of composite processing of EDM and ultrasonic vibration drilling for machining precision micro-holes in complex positions of superalloys.Design/methodology/approachA six-axis computer numerical control (CNC) machine tool was developed, whose software control system adopted a real-time control architecture that integrates electrical discharge and ultrasonic vibration drilling. Among them, the CNC system software was developed based on Windows + RTX architecture, which could process the real-time processing state received by the hardware terminal and adjust the processing state. Based on the SoC (System on Chip) technology, an architecture for a pulse generator was developed. The circuit of the pulse generator was designed and implemented. Additionally, a composite mechanical system was engineered for both drilling and EDM. Two sets of control boards were designed for the hardware terminal. One set was the EDM discharge control board, which detected the discharge state and provided the pulse waveform for turning on the transistor. The other was a relay control card based on STM32, which could meet the switch between EDM and ultrasonic vibration, and used the Modbus protocol to communicate with the machining control software. FindingsThe mechanical structure of the designed composite machine tool can effectively avoid interference between the EDM spindle and the drilling spindle. The removal rate of the remelting layer on 1.5 mm single crystal superalloys after composite processing can reach over 90%. The average processing time per millimeter was 55 s, and the measured inner surface roughness of the hole was less than 1.6 µm, which realized the micro-hole machining without remelting layer, heat affected zone and micro-cracks in the single crystal superalloy.Originality/valueThe test results proved that the key techniques developed in this paper were suite for micro-hole machining of special materials.

Development of a prototype to evaluate and monitor energy efficiency aiming at power quality 4.0

In research and development projects, the need to implement prototypes to speed up the development and delivery process is paramount, offering tools to validate scenarios and anticipate challenges. The aim of this research is to experimentally develop a prototype for monitoring electrical power systems using a gateway that converts MODBUS-RTU communication protocols to TCP, providing useful information for technicians and managers of a company in the Manaus Industrial Estate (PIM) in the field of reflective tapes. To achieve this goal, it was necessary to specify the technical requirements for panel assembly and communication via MODBUS, acquire and research materials in accordance with the technical specifications and technological requirements, implement the monitoring system with an IMS Controller for reactive power compensation, and configure and parameterise the MODBUS protocol via the RTU to TCP converter. The prototype is expected to be able to take accurate measurements and, in the data acquisition process, obtain readings of electrical quantities such as: voltage per phase; current per phase; power factor per phase; active power per phase; reactive power per phase; apparent power per phase; frequency; voltage THD and voltage harmonics. The prototype must act intelligently to drive the capacitor bank to control and monitor reactive power. The development of the prototype included crucial stages such as the specification of technical requirements, the acquisition of suitable materials, and the implementation and configuration of the system. The specification ensured that the components were aligned with the project objectives, while the procurement of materials ensured the quality and efficiency of the system. The implementation of the Automatic Reactive Power Compensation Controller was vital for reactive power compensation and the configuration of the MODBUS protocol ensured precise communication between the components. To summarise, this project demonstrates the importance of prototypes in technological advancement, offering practical and efficient solutions for industry. The prototype developed to monitor electrical power systems through a MODBUS-RTU to TCP protocol converter gateway represents a significant advance, providing essential data and contributing to informed decision-making, improving the performance and management of the company's energy resources.

Real-Time Monitoring of Cable Sag and Overhead Power Line Parameters Based on a Distributed Sensor Network and Implementation in a Web Server and IoT.

Based on the need for real-time sag monitoring of Overhead Power Lines (OPL) for electricity transmission, this article presents the implementation of a hardware and software system for online monitoring of OPL cables. The mathematical model based on differential equations and the methods of algorithmic calculation of OPL cable sag are presented. Considering that, based on the mathematical model presented, the calculation of cable sag can be done in different ways depending on the sensors used, and the presented application uses a variety of sensors. Therefore, a direct calculation is made using one of the different methods. Subsequently, the verification relations are highlighted directly, and in return, the calculation by the alternative method, which uses another group of sensors, generates both a verification of the calculation and the functionality of the sensors, thus obtaining a defect observer of the sensors. The hardware architecture of the OPL cable online monitoring application is presented, together with the main characteristics of the sensors and communication equipment used. The configurations required to transmit data using the ModBUS and ZigBee protocols are also presented. The main software modules of the OPL cable condition monitoring application are described, which ensure the monitoring of the main parameters of the power line and the visualisation of the results both on the electricity provider's intranet using a web server and MySQL database, and on the Internet using an Internet of Things (IoT) server. This categorisation of the data visualisation mode is done in such a way as to ensure a high level of cyber security. Also, the global accuracy of the entire OPL cable sag calculus system is estimated at 0.1%. Starting from the mathematical model of the OPL cable sag calculation, it goes through the stages of creating such a monitoring system, from the numerical simulations carried out using Matlab to the real-time implementation of this monitoring application using Laboratory Virtual Instrument Engineering Workbench (LabVIEW).

Design of wireless transmission system for intelligent agricultural greenhouse data acquisition based on modbus communication protocol

Abstract Traditional agricultural greenhouses rely too much on manual labor and have a poor ability to adjust the key factors that affect crop growth, such as temperature, humidity, and illumination, resulting in low production efficiency and unstable product quality. Based on the MODBUS communication protocol, a set of intelligent agricultural greenhouse data acquisition wireless transmission systems is designed in this paper. Intelligent instruments, sensors, wireless transmission equipment, and smart control equipment (PLC) have been introduced in agricultural greenhouses. These sensors and instruments automatically collect data and wirelessly transmit it to the intelligent control system in the control room, which is located a few kilometers away. The intelligent control system processes the data and generates various control instructions which are then transmitted to the executive mechanism in agricultural greenhouses for implementation. We complete automatic adjustment of temperature, humidity, illuminance, and other parameters and operations. The intelligent, large-scale, and unmanned agricultural greenhouses are realized. It greatly improves the production efficiency and product quality of crops.

Modbus Extension Server Implementation for BIoT-Enabled Smart Switch Embedded System Device.

The industrial control and automation sector has invested in the development and standardization of new wireless (WirelessHART, ISA 100.11a, and WIA-PA) and wired (Profibus/Profinet, Modbus, and LonWORK) solutions aimed at automating processes to support standard monitoring and control functions from the perspective of addressing critical applications, as well as those integrated within the Building Internet of Things (BIoT) concept. Distributed data acquisition and control systems allow modern installations to monitor and control devices remotely. Various network protocols have been proposed to specify communication formats between a client/gateway and server devices, with Modbus being an example that has been widely implemented in the latest industrial electrical installations. The main contribution made in this paper concerns the completion of the Modbus Extension (ModbusE) specifications for the server station in the classical Modbus communication architecture, as well as their implementation and testing in an STM32F4 kit. A general-purpose control architecture is proposed for BIoT sector, comprising both intelligent touch switches and communication protocols of which the Modbus protocol is used extensively for the monitoring and control part, especially between clients, smart switches, and devices. The specific contributions concern the presentation of a scientific and practical implementation of improved specifications and their integration as software modules on ModbusE protocol server stations. A client station with a VirtualComm USB PC connection is also implemented in the lab to test the operation of the proposed server with specific Modbus applications.

Solar-Powered Smart Buildings: Integrated Energy Management Solution for IoT-Enabled Sustainability

The increasing demand for energy-efficient and sustainable solutions in the building sector has driven the need for innovative approaches that integrate renewable energy sources and advanced control systems. This paper presents an integrated energy management solution for solar-powered smart buildings, combining a multifaceted physical system with advanced IoT- and cloud-based control systems. The physical system includes a heat pump, photovoltaics, solar thermal panels, and an innovative low-enthalpy radiant wall and ceiling, providing self-sufficient heating and cooling. The control system makes use of advanced IoT and communication engineering technologies, using Modbus, HTTP, and MQTT protocols for seamless interconnectivity, monitoring, and remote management. The successful implementation of this solution in an average-sized model house in Paris and a deep energy retrofit of a semidetached single-family house in Oviedo, northern Spain, demonstrates increased energy efficiency, improved thermal comfort, and reduced environmental impact compared with conventional alternatives. This study illustrates the potential of integrating solar energy, IoT, and communication technologies into smart buildings, contributing to the global effort to reduce the environmental impact of the building sector.

Improvement of a mine’s ventilation test bench, using industrial communication and open-source microcontrollers.

This paper shows the results of optimizing a test bed used to simulate parameters related to Underground mines ventilation. The data acquisition card was changed for an Arduino microcontroller; likewise, some sensors were changed for more precise ones, and a sensor was adapted to measure relative humidity, dry temperature, and heat index. The measurements will continue to be observed using the LabVIEW software and complemented by an industrial communication system, the Modbus protocol. This protocol increases the data transmission speed of Ethernet. With the improvement of the system, the precision in the parameters (Pressure, temperatures, relative humidity, concentration of methane gas, Voltage, current) increases, and ultra-fast data transmission is guaranteed.

Artificial Intelligence for the Classification of Plastic Waste Utilizing TinyML on Low-Cost Embedded Systems

BCG's implementation of the economy makes Thailand more environmentally conscious. The consolidation policy encourages consumers to eliminate single-use plastics using the 3Rs. This article introduces a solution to reduce plastic waste drastically using artificial intelligence. Utilizing a low-cost Arducam Pico4ML embedded device and TinyML, a plastic waste classifying system prototype is developed for plastic bottle segregation. The grayscale image datasets of PET, HDPE plastic bottles, and unknown objects are adjusted in the image pre-processing state and utilized to create trained models using MobileNetV2 convolutional-based neural network algorithms. Effective feature extraction and model training are performed on the Edge Impulse platform, and the trained model is exported to an embedded device using the optimized compiler. A further RS485 Modbus communication protocol feature enables integration with a programmable logic controller (PLC). The validation results of the trained model indicate a classification performance of 100% accuracy. Based on the average precision results, it is notable that the trained model can recognize the most common waste with an average accuracy of over 90%. The minimum classification rate of the MobileNetV2 quantized model is 249 milliseconds. It is also implemented in low-cost embedded devices for real-time plastic waste classification using fewer processing resources (185.4K ROM and 88K RAM). The findings exhibit sequential contributions that satisfy the criteria for classifying plastic bottles and the machine's integration capacity. These outcomes are anticipated to foster social shifts in behavior and enhance public awareness about plastic waste management.

Artificial Intelligence for the Classification of Plastic Waste Utilizing TinyML on Low-Cost Embedded Systems

BCG's implementation of the economy makes Thailand more environmentally conscious. The consolidation policy encourages consumers to eliminate single-use plastics using the 3Rs. This article introduces a solution to reduce plastic waste drastically using artificial intelligence. Utilizing a low-cost Arducam Pico4ML embedded device and TinyML, a plastic waste classifying system prototype is developed for plastic bottle segregation. The grayscale image datasets of PET, HDPE plastic bottles, and unknown objects are adjusted in the image pre-processing state and utilized to create trained models using MobileNetV2 convolutional-based neural network algorithms. Effective feature extraction and model training are performed on the Edge Impulse platform, and the trained model is exported to an embedded device using the optimized compiler. A further RS485 Modbus communication protocol feature enables integration with a programmable logic controller (PLC). The validation results of the trained model indicate a classification performance of 100% accuracy. Based on the average precision results, it is notable that the trained model can recognize the most common waste with an average accuracy of over 90%. The minimum classification rate of the MobileNetV2 quantized model is 249 milliseconds. It is also implemented in low-cost embedded devices for real-time plastic waste classification using fewer processing resources (185.4K ROM and 88K RAM). The findings exhibit sequential contributions that satisfy the criteria for classifying plastic bottles and the machine's integration capacity. These outcomes are anticipated to foster social shifts in behavior and enhance public awareness about plastic waste management.

Distributed Generation Control Using Ripple Signaling and a Multiprotocol Communication Embedded Device

Remotely performing real-time distributed generation control and a demand response is a basic aspect of the grid ancillary services provided by grid operators, both the transmission grid operators (TSOs) and distribution grid operators (DNOs), in order to ensure that voltage, frequency and power loads of the grid remain within safe limits. The stochastic production of electrical power to the grid from the distributed generators (DGs) from renewable energy sources (RES) in conjunction with the newly appeared stochastic demand consumers (i.e., electric vehicles) hardens the efforts of the DNOs to keep the grid’s operation within safe limits and prevent cascading blackouts while staying in compliance with the SAIDI and SAIFI indices during repair and maintenance operations. Also taking into consideration the aging of the existing grid infrastructure, and making it more prone to failure year by year, it is yet of great significance for the DNOs to have access to real-time feedback from the grid’s infrastructure—which is fast, has low-cost upgrade interventions, is easily deployed on the field and has a fast response potential—in order to be able to perform real-time grid management (RTGM). In this article, we present the development and deployment of a control system for DG units, with the potential to be installed easily to TSO’s and DNO’s substations, RES plants and consumers (i.e., charging stations of electric vehicles). This system supports a hybrid control mechanism, either via ripple signaling or through a network, with the latter providing real-time communication capabilities. The system can be easily installed on the electric components of the grid and can act as a gateway between the different vendors communication protocols of the installed electrical equipment. More specifically, a commercially available, low-cost board (Raspberry Pi) and a ripple control receiver are installed at the substation of a PV plant. The board communicates in real-time with a remote server (decision center) via a 5G modem and with the PV plants inverters via the Modbus protocol, which acquires energy production data and controls the output power of each inverter, while one of its digital inputs can be triggered by the ripple control receiver. The ripple control receiver receives on-demand signals with the HEDNO, triggering the digital input on the board. When the input is triggered, the board performs a predefined control command (i.e., lower the inverter’s power output to 50%). The board can also receive control commands directly from the remote server. The remote server receives real-time feedback of the acquired inverter data, the control signals from the ripple control receiver and the state and outcome of each performed control command.

A new low‐cost and low‐power industrial internet of things infrastructure for effective integration of distributed and isolated systems with smart grids

AbstractInternet of Things (IoT) has recently become one of the fast‐growing technologies in the world. Integrating existing systems with smart grids still represents a significant challenge arising from the massive cost of upgrading the infrastructure. This paper provides an IoT infrastructure solution based on a newly designed low‐cost microcontroller‐based IoT remote terminal unit (RTU) to integrate new, old, and conventional sites of existing grids with smart grids. The IoT RTU supports Wi‐Fi communication and includes digital/analog inputs and outputs besides the advantage of serial data transmission standard RS‐485 as an industrial field communication (IFC). The Modbus communication protocol is utilized as a serial industrial protocol that can be interfaced over the RS‐485 standard. The advantage of having an IFC protocol integrated into the IoT infrastructure enables to link any supported device and publish the required data to the cloud, besides the ability to add smart metering technologies, which allows Advanced Metering Infrastructure (AMI) in these areas. IoT‐enabled Supervisory Control and Data Acquisition (SCADA) system is integrated with the proposed IoT infrastructure for its advantages of remote monitoring and control. The proposed IoT infrastructure is characterized by proper data security and low power consumption. The IoT infrastructure is simulated with an existing real application for proof of concept, and the results are discussed for different case studies.

Design and Performance Analysis of Monitoring System for Seed Metering and Fertilization of Precision Seeder Based on Photoelectric Sensor

In order to realize accurate monitoring of wheat sowing and fertilization process and ensure efficient and reliable sowing operation, an integrated monitoring system of wheat sowing and fertilization based on variable-distance photoelectric sensor is designed. The monitoring system includes the hardware circuit of STM32F103 lower computer and the human-machine interface of the upper computer touch screen. The hardware circuit of the lower computer is composed of OH-1021 photoelectric sensor, signal shaping and amplifying circuit, encoder speed acquisition module, communication module, central processor, and peripheral circuits. The information of seed fertilizer flow and seed fertilizer shaft rotation is obtained through the reflective photoelectric sensor and rotary encoder respectively to judge the running state of sowing. The information is transmitted to the human-machine interface of the upper computer touch screen of MCGS by means of Modbus communication protocol. In the experimental species, the single seed monitoring accuracy of the monitoring system reaches 98.6%. Compared with the test results of the performance test bench of the seed metering device, the monitoring error of the monitoring system is less than 0.3%, the monitoring error of the replay rate is less than 0.6%, and the monitoring accuracy of the seeding amount is greater than 94%. The simulation results of the seed metering monitoring circuit of the lower computer show that the detection distance of the amplifier circuit to the photoelectric sensor of the seed tube changes by [4 mm, 7 mm]. The communication test results of the upper and lower computers show that the accuracy of data transmission reaches 100%, the monitoring system shows that the accuracy of fault detection exceeds 90%, and the response time of lacking, blocking, and leaking is less than 0.3 s. The monitoring system realizes high-precision monitoring of wheat seed metering and fertilization, which is helpful to improve the quality of wheat planting.

Correction to: a novel method to detect cyber-attacks in IoT/IIoT devices on the modbus protocol using deep learning

Correction to: a novel method to detect cyber-attacks in IoT/IIoT devices on the modbus protocol using deep learning

A novel method to detect cyber-attacks in IoT/IIoT devices on the modbus protocol using deep learning

A novel method to detect cyber-attacks in IoT/IIoT devices on the modbus protocol using deep learning

Real-Time Monitoring of Gas Fields: Prototype at Pt Gamma Energi Pratama Bogor

PT Gamma Energi Pratama is a company engaged in the instrumentation sector. One of the projects undertaken by PT Gamma Energi Pratama is on an oil and natural gas drilling site. The oil drilling process involves a tool called a Gas Jack Compressor originating from the United States. At first, the technician there used the local panel that came with the compressor. But procuring spare parts takes a long time. At the same time, the needs in the field demand to be met immediately. Therefore, the Programmable Logic Controller (PLC) was chosen as a special microcontroller device that can access the compressor via the Modbus Protocol. PLCs can also be connected to Supervisory Control and Data Acquisition (SCADA) applications via Ethernet. This solution monitors data from sensor readings installed on the Gas Jack Compressor. The system is already running with its use only on the local scope. For the development of the system so that monitoring can be carried out in real-time and online, it needs to be linked to flow control devices, database systems, and interfaces for data visualization. Thus, monitoring gas fields can be done in real-time online.

The Industrial IoT Control Design of Three Phase Induction Motor using Conventional V/F Method

Nowadays, the Internet of Things (IoT) is inseparable from the industrial revolution 4.0 and society 5.0. IoT allows all aspects to be connected at the same time. In industrial processes, the IoT controls the actuator and monitors the behavior system. Industrial IoT (IIoT) connected the Human Machine Interface (HMI) Haiwell C7S with the actuator (Schneider Altivar 12) and the controller (OMRON CP1E-NA20DRA). The communication between the variable speed drive and Haiwell C7S using Modbus protocol is connected with RS485. Schneider Altivar 12 is a variable-speed drive that controls the Induction Motor (IM) rotor speed using the conventional V/F method. The scalar control of IM controls supply frequency and voltage simultaneously. The success parameter of the proposed systems is a rotor speed response and voltage in various supply frequencies. The results show that the 5 Hz supply frequency makes the absolute error of rotor speed response 11.43% for tachometer measurement, 0.67% from VSD data, and 12.67% for rotary encoder measurement. This absolute error will decrease significantly when the supply frequency exceeds 20 Hz, or the rotor speed response exceeds 1200 rpm. The changes in the supply frequency change the voltage's magnitude. The voltage will increase proportionally, along with the increase in supply frequency.

A Continuous Production Apparatus for a Frame-Type Melt-Blown Filter Cartridge with Various Properties and Geometry

Polypropylene (PP) melt-blown (MB) filter cartridges are widely used in many fields requiring water purification, such as households, the food industry, industrial processes, and recycled water filtration. While the demand for filters has gradually increased, the environmental requirements and conditions have become severe. The filters are easily deformed from higher liquid pressure during operation and setup and need to be replaced frequently. With the lifetime of filters shortened, manpower increases to replace filters. Hence, the inner structure of a PP melt-blown filter cartridge is supported by a frame structure to resist higher liquid pressure for enhancing filtration efficiency and lifetime. The filter, known as a “frame-type melt-blown filter cartridge”, does not affect the user’s application environment and equipment. This article focuses on developing continuous production equipment for frame-type melt-blown filter cartridges. The core technology of the equipment is the mechanism design for conveying frame tubes integrated with the MB process. The PP fiber is simultaneously melted and blown on the frame tube, and the frame tube needs to be pushed forward while rotating. This mechanism can independently control the fiber’s rotational speed and push speed. The rotational speed affects the surface density, fiber diameter, and porosity of the melt-blown filter cartridge, and the push speed affects the core diameter and weight of the melt-blown filter cartridge. In addition, there is a frame tube feeding device at the input end of the conveying equipment for continuously carrying the frame tube. Then, the finally formed melt-blown filter cartridges enter the cutting machine to trim a certain length to complete a frame-type melt-blown filter cartridge. The complexity of the operation is simplified by a human–machine interactive interface. A programmable logic controller (PLC) and a LabVIEW human–machine interactive interface are used to dominate the equipment. The Modbus communication protocol is adopted for connecting and communicating between PLC and LabVIEW. The interface can integrate and analyze the process data, including overall equipment effectiveness (OEE), total effective equipment performance (TEEP), loading time, utilization, performance, and yield. The entire production process of the frame-type melt-blown filter cartridge is optimized, and the traditional output of 1000 per day is upgraded to 1300. Overall, the processing speed is increased by up to 30%.

Research on cloud-edge AC Power Monitoring Systems based on MODBUS

With the development of the Internet of Things and automation technology in the industry, the types of equipment in the industrial field are increasing, and the data parameters of the industrial process are gradually becoming complex. It puts forward higher requirements for the system perception layer’s real-time performance, reliability, and maintainability. The original data acquisition architecture is not easy to ensure the reliable transmission and real-time processing of massive industrial data. In order to solve these problems, this paper designs an AC Power Monitoring System. It proposes a cloud edge computing framework based on MODBUS: First, the data is collected and sent to the edge server by MODBUS through the RS485 bus. Second, combined with the advantages of the powerful service capability of cloud computing resources and the low transmission delay of edge computing, the edge side and cloud side will work together. Finally, the functions of data reading, uploading and sending, correction, configuration, and fault alarm are realized. The field operation shows that using a cloud edge computing framework can reduce the processing pressure of cloud computing, reduce network latency and lower requirements for network bandwidth and make the system efficient and safe for collecting and analyzing big data. The cooperation of MODBUS protocol enhances the reliability and practicability of communication. The cloud edge computing system based on MODBUS is easy to design and maintain and is suitable for many monitoring systems, which have high promotion value.