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Hierarchical Levels Industrial Networks align device, control, and enterprise layers across PLCs, SCADA, MES, and ERP, using fieldbus, Ethernet/IP, and Profinet to ensure deterministic control, real-time data, cybersecurity, and scalable OT-IT integration.

What Are Hierarchical Levels Industrial Networks?

Layered OT networks linking devices, control, and enterprise systems for real-time, deterministic, secure automation.

✅ Defines device, control, and enterprise layers in OT/ICS

✅ Maps PLCs, HMIs, drives, and sensors to appropriate network tiers

✅ Ensures determinism, redundancy, and EMC-compliant cabling practices

The industrial automation systems can be very complex, and it is usually structured into several hierarchical levels. Each of the hierarchical level has an appropriate communication level, which places different requirements on the communication network. Figure 1.1 shows an example of the hierarchy of an industrial automation system. For a broader overview of protocols and trends, industrial automation communication resources explain how hierarchy influences network design across levels.

Industrial networks may be classified in several different categories based on functionality - field-level networks (sensor, actuator or device buses), control-level networks (control buses) and information-level networks. Organizations adopt these layers to gain measurable efficiencies, and the benefits of industry networks include improved interoperability, uptime, and lifecycle support.

We primarily use sensor and actuator buses to connect simple, discrete devices with limited intelligence, such as a photo-eye, limit switch, or solenoid valve, to controllers and computers. Sensor buses such as ASI and CAN are designed so information flow is reduced to a few bits and the cost per node is a critical factor. Selecting cabling, interfaces, and gateways depends on understanding industrial network components that shape reliability, diagnostics, and scalability.

Field level

The lowest level of the automation hierarchy is the field level, which includes the field devices such as actuators and sensors. The elementary field devices are sometimes classified as the element sublevel. The task of the devices in the field level is to transfer data between the manufactured product and the technical process. The data may be both binary and analogue. Measured values may be available for a short period of time or over a long period of time.

For the field level communication, parallel, multiwire cables, and serial interfaces such as the 20mA current loop has been widely used from the 

past. The serial communication standards such as RS232C, RS422, and RS485 are most commonly used protocols together with the parallel communication standard IEEE488. Those point-to-point communication methods have evolved to the bus communication network to cope with the cabling cost and to achieve a high quality communication. Comparisons of copper, fiber, and wireless media, along with signaling and topology choices, are covered in transmission methods for industrial networks to help match performance with environmental constraints.

Field-level industrial networks are a large category, distinguished by characteristics such as message size and response time. In general, these networks connect smart devices that work cooperatively in a distributed, time-critical network. They offer higher-level diagnostic and configuration capabilities generally at the cost of more intelligence, processing power, and price. At their most sophisticated, fieldbus networks work with truly distributed control among intelligent devices like FOUNDATION Fieldbus. Common networks included in the devicebus and fieldbus classes include CANOpen, DeviceNet, FOUNDATION Fieldbus, Interbus-S, LonWorks, Profibus-DP, and SDS.

These characteristics also underpin infrastructure applications such as rail crossings, where distributed sensors and controllers coordinate safety logic, as seen in smart city automated level crossings that rely on deterministic messaging.

Nowadays, the fieldbus is often used for information transfer in the field level. Due to timing requirements, which have to be strictly observed in an automation process, the applications in the field level controllers require cyclic transport functions, which transmit source information at regular intervals. The data representation must be as short as possible in order to reduce message transfer time on the bus.

Control Level

At the control level, the information flow mainly consists of the loading of programs, parameters and data. In processes with short machine idle times and readjustments, this is done during the production process. In small controllers it may be necessary to load subroutines during one manufacturing cycle. This determines the timing requirements. It can be divided into two: cell and area sublevels.

Cell Sublevel

For the cell level operations, machine synchronizations and event handlings may require short response times on the bus. These real-time requirements are not compatible with time-excessive transfers of application programs, thus making an adaptable message segmentation necessary.

In order to achieve the communication requirements in this level, local area networks have been used as the communication network. After the introduction of the CIM concept and the DCCS concept, many companies developed their proprietary networks for the cell level of an automation system. The Ethernet together with TCP/IP (transmission control protocol/internet protocol) was 

accepted as a de facto standard for this level, though it cannot provide a true real-time communication. Similar patterns appear in buildings, where building automation systems integrate HVAC, lighting, and security over IP while reserving real-time tasks for specialized buses.

Many efforts have been made for the standardization of the communication network for the cell level. The IEEE standard networks based on the OSI layered architecture were developed and the Mini-MAP network was developed in 1980s to realize a standard communication between various devices from different vendors. Some fieldbuses can also be used for this level.

Area sublevel

The area level consists of cells combined into groups. Cells are designed with an application-oriented functionality. By the area level controllers or process operators, the controlling and intervening functions are made such as the setting of production targets, machine startup and shutdown, and emergency activities.

We typically use control-level networks for peer-to-peer networks between controllers such as programmable logic controllers (PLCs), distributed control systems (DCS), and computer systems used for human-machine interface (HMI), historical archiving, and supervisory control. We use control buses to coordinate and synchronize control between production units and manufacturing cells. Typically, ControlNet, PROFIBUS-FMS and (formerly) MAP are used as the industrial networks for controller buses. In addition, we can frequently use Ethernet with TCP/IP as a controller bus to connect upper-level control devices and computers.

Information level

The information level is the top level of a plant or an industrial automation system. The plant level controller gathers the management information from the area levels, and manages the whole automation system. At the information level there exist large scale networks, e.g. Ethernet WANs for factory planning and management information exchange. We can use Ethernet networks as a gateway to connect other industrial networks. At this level, analytics platforms often drive energy KPIs, and advanced energy management strategies leverage network data for optimization and demand response.

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What is building automation? An integrated BAS/BMS using sensors, PLCs, and SCADA to control HVAC, lighting, power distribution, VFDs, and safety systems, improving energy management, demand response, monitoring, reliability, and analytics.

What Is Building Automation?

A BAS/BMS that controls electrical systems for efficiency, safety, and performance.

✅ Controls HVAC, lighting, and power via PLCs, sensors, and actuators

✅ Enables energy management, demand response, and load shedding

✅ Integrates SCADA, metering, and VFDs for reliability and safety

What is Building Automation?

Building automation is crucial in creating sustainable, efficient, and comfortable living and working environments. By incorporating advanced technologies like IoT and data analytics, building automation systems can optimize energy consumption, enhance occupant comfort, and promote cost-effective building management. As technology continues to evolve, building automation's potential benefits and applications are set to expand further, making it an essential aspect of modern building design and operation. For foundational context on how organizations plan, monitor, and optimize consumption, consult this energy management primer that aligns with modern building objectives.

Building automation refers to the centralized building control system for various systems, such as heating, ventilation, air conditioning (HVAC), lighting, security systems, and other related subsystems. The main objective of a building automation system (BAS) is to optimize energy consumption, enhance the comfort of occupants, and ensure that the building operates efficiently and cost-effectively. A concise primer on system architectures and typical functions is provided in the building automation system overview, which clarifies scope and capabilities.

A BAS comprises interconnected components and subsystems, including sensors, controllers, and user interfaces. Sensors measure temperature, humidity, and occupancy, while controllers use this information to regulate various building systems, such as air conditioning and lighting. User interfaces enable facility managers and authorized personnel to monitor and adjust system settings as needed. To understand how setpoints, scheduling, and feedback loops are orchestrated, explore energy management controls guidance that illustrates controller strategies.

One of the primary benefits of building automation is its ability to reduce energy consumption and enhance energy efficiency for building owners. A BAS can optimize energy usage and minimize waste by continuously monitoring and adjusting building systems based on real-time data. For example, automated control of lighting and HVAC systems can help maintain optimal temperature and lighting levels while conserving energy when spaces are unoccupied. This leads to lower utility bills and a reduced carbon footprint. These practices are often formalized within building energy management systems frameworks that standardize analytics and reporting.

Building automation also promotes cost-effective building management system by reducing maintenance and operational costs. A well-designed BAS can detect and address potential issues before they escalate into expensive problems, allowing facility managers to maintain building systems and extend their life expectancy proactively. Additionally, building automation control can help maximize the productivity and comfort of building occupants by maintaining a consistent and pleasant indoor environment. When aligned with enterprise objectives, broader energy management systems can integrate with BAS workflows to coordinate maintenance and savings.

The Internet of Things (IoT) plays a significant role in the development and advancement of building automation. IoT output devices and sensors provide a wealth of real-time data that can be analyzed and leveraged to enhance building performance further. This integration allows for more precise control and monitoring of building systems and the developing of new, innovative energy management and conservation solutions. This data-driven approach enables advanced energy management techniques that support predictive control and optimization.

What is Building Automation?

Building automation is also closely linked to facility management, as both disciplines aim to optimize the operation and maintenance of building systems. By integrating building automation with facility management software, facility managers can monitor and control various building systems more effectively, streamline maintenance tasks, and make data-driven decisions to optimize building performance. Interoperability relies on reliable industrial automation communication methods that allow platforms to share telemetry securely.

The future of building automation technology holds exciting possibilities, including the development of increasingly intelligent and interconnected systems. In addition, advances in artificial intelligence, machine learning, and data analytics will enable BAS to become even more efficient and responsive to changing conditions, resulting in greater energy savings and reduced environmental impact.

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Green energy integrates renewable electricity from solar, wind, and hydro into smart grids using power electronics, advanced inverters, energy storage, and grid automation to enhance reliability, power quality, and low-carbon transmission.

What Is Green Energy?

Green energy is renewable electricity from solar, wind, and hydro, using power electronics, smart grids, and storage.

✅ Power electronics and inverters convert PV DC to grid-synchronous AC.

✅ Smart grids manage variable renewables with SCADA, EMS, and demand response.

✅ Energy storage and microgrids enhance reliability, power quality, and resilience

Green energy, often synonymous with renewable energy, has gained significant attention in recent years as the world seeks to reduce its reliance on fossil fuels, minimize environmental damage, and promote a more sustainable future. This shift towards clean energy resources helps reduce greenhouse gases and air pollutants and plays a vital role in conserving non-renewable resources and promoting efficiency.

There are several green energy sources, each with unique benefits and challenges. Solar energy, one of the most popular renewable sources, harnesses the sun's energy to generate electricity. Solar panels, commonly installed on rooftops or in solar farms, convert sunlight into electricity for homes and businesses. As solar technology advances, solar system installation costs have dropped significantly, making it more accessible to individuals and communities alike. For homeowners, adopting comprehensive strategies is easier when using resources like energy management frameworks that track consumption and optimize production.

Wind energy, another widely recognized green energy source, is generated by converting the kinetic energy of wind into electricity using wind turbines. Large wind farms can produce significant energy, often enough to power entire communities or cities. However, wind power's effectiveness depends on the location and weather conditions, as wind speeds must be sufficient to generate electricity consistently. To mitigate variability, utilities often integrate energy management systems to balance wind output with demand forecasts.

Hydropower, one of the oldest renewable green energy sources, utilizes the movement of water to generate electricity. Dams and hydroelectric power stations convert the potential energy of water stored at a height into electricity, providing a stable and reliable source of energy. However, the construction of dams can lead to environmental concerns, such as habitat disruption and changes to local ecosystems. In facilities adjacent to dams, building energy management systems can tune loads to align with scheduled releases for greater efficiency.

Biomass energy is derived from organic materials, such as plants and animal waste, which can be burned directly for heat or converted into biofuels, such as ethanol and biodiesel. This form of green energy can help reduce waste and greenhouse gas emissions. However, the large-scale production of biomass crops can compete with food production and lead to deforestation. Modern plants deploy energy management controls to maintain combustion efficiency and emissions performance across feedstock variations.

Geothermal green energy taps into the Earth's natural heat by capturing steam or hot water from underground reservoirs to generate electricity. This clean energy source has a minimal environmental impact, but its availability is limited to areas with specific geological conditions. In buildings served by district geothermal, integrating building automation enables coordinated HVAC setpoints and thermal storage strategies.

Green energy offers numerous environmental benefits, such as reducing greenhouse gas emissions, air pollution, and dependence on finite energy resources like coal, oil, and natural gas. By transitioning to renewable green energy sources, we can significantly reduce our carbon footprint and mitigate the effects of climate change. Additionally, green energy technologies can create new job opportunities and stimulate economic growth.

However, there are also some drawbacks to green energy sources. For example, intermittency issues can arise with solar and wind power, depending on weather conditions. Moreover, the initial investment for installing renewable energy systems can be high, although costs have decreased recently.

Individuals can contribute to the growth of green energy by installing solar panels in their homes, using energy-efficient appliances, and supporting policies that encourage the adoption of renewable energy sources. The cost of switching to green energy varies depending on the technology, location, and government incentives available.

Emerging trends in green energy technology include advancements in energy storage solutions, such as batteries and hydrogen storage, which can help address intermittency issues. Furthermore, innovations in smart grids and microgrids allow for better integration and management of renewable sources. These improvements are complemented by advanced energy management analytics that forecast loads and orchestrate distributed assets.

Government policies play a critical role in supporting the adoption of green energy. For example, incentive programs, tax credits, and subsidies can help lower the cost of renewable power installations, making them more accessible to consumers. Additionally, regulations and targets for reducing greenhouse gas emissions and increasing the use of renewable sources can drive further investment in green energy technologies. Organizations can accelerate adoption by instituting a formal energy management program that aligns incentives, metering, and continuous commissioning efforts.

Embracing green energy sources is crucial for building a sustainable and cleaner future. By understanding the different types of green energy and their environmental benefits, individuals and governments can make informed decisions to promote adopting green energy solutions.

As the United States and other countries worldwide continue to invest in renewable technologies, the production landscape is rapidly changing. This transition to green energy sources is essential to reducing our reliance on fossil fuels, minimizing the environmental impacts of energy production, and ensuring a sustainable future for generations to come.

Increasing public awareness and education is one way to promote green energy further. By informing citizens of the benefits and potential drawbacks of different renewable sources, we can foster a more informed and engaged public, encouraging individuals to make greener choices in their daily lives.

Community-based green energy renewable projects can also help facilitate the widespread adoption of green energy. These projects, such as community solar gardens or small-scale wind farms, allow individuals who may need more resources or space to install their renewable systems to benefit from clean energy production. In addition, by pooling resources and sharing the benefits, communities can work together to create a more sustainable future.

Advancements in green energy technologies will also play a significant role in increasing the adoption of renewable sources. As researchers and engineers continue to develop more efficient and affordable technologies, the barriers to entry for green energy will continue to decrease. In addition, innovations in materials science, such as the development of more efficient solar cells or improvements in wind turbine design, can lead to significant gains in the performance of renewable systems.

Finally, international cooperation and collaboration will be essential in advancing green energy on a global scale. Climate change and environmental degradation do not respect national borders; thus, a united effort is necessary to combat these challenges. By sharing knowledge, resources, and technology, countries can work together to promote the adoption of green energy and build a more sustainable future for all.

Green energy is an essential component of a sustainable, environmentally responsible future. Investing in renewable technologies, supporting government policies, and engaging in individual and community-based efforts can help drive the adoption of green energy sources and ensure a cleaner, healthier world for future generations. With continued innovation, increased public awareness, and international collaboration, the promise of a green energy revolution becomes more attainable each day.

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Advanced energy management integrates smart grid analytics, demand response, and SCADA/IoT sensors to optimize loads, enable peak shaving, enhance power quality, and coordinate renewables, storage, and microgrids for efficient, resilient electrical systems.

What Is Advanced Energy Management?

A control-and-analytics approach to optimize electrical loads, integrate renewables and storage, and improve reliability.

✅ Load forecasting and demand response reduce peaks and costs.

✅ SCADA, IoT, and EMS enable real-time monitoring and control.

✅ Optimizes power quality, peak shaving, and asset utilization.

Advanced energy management systems involve control systems and processes. Control systems can be as simple as a residential thermostat, to very complex computer controlled systems for multiple buildings, to industrial process control. Their diligence and repeatability can also serve to maintain the savings of project improvements for years, further justifying their existence by providing economic return to the customer. Advanced energy management systems include control technology and control mode categories, basic input and output instrumentation, and the practical need to temper “things possible” with the skill level of the operators who will inherit it. The importance of advanced energy management system controllability and user-friendliness as primary design parameters will be stressed. Industry overviews of energy management systems highlight common architectures and integration paths useful during early design.

The following is a very important first statement before any discussion about control hardware: “The type of advanced energy management systems hardware used in optimization is less important than the understanding of the process and of the control concepts that are to be implemented.” The main goal should be to become clear about the process fundamentals and what should happen—then the parts and pieces are just details. This discussion of different available hardware types is a familiar but sometimes laborious and dull part of any controls text. Remember that automatic controls are really nothing more than machines that do for us what we would do ourselves if we had nothing better to do; they do work for us like any other tool, and they are only as clever as the people who craft them. As a complement, primers on energy management controls summarize control modes and device families that support these concepts.

The field of automatic control in advanced energy management systems is similar in that we continually adjust some device to cause a particular measured variable to remain at a desired state. In facilities practice, deploying a building automation system provides the supervisory layer that implements such setpoint maintenance and scheduling.

Examples:

• The need to throttle heating and cooling equipment sized for maximum load that is effectively over-sized at part load conditions. Within building energy management systems these strategies are automated through reset logic and variable speed control for stable part-load operation.

• Varying occupancy, and systems attendant to the occupants (lighting, ventilation). Guides on energy management emphasize occupancy-based control sequences that tie lighting and ventilation to real-time demand.

• Varying product throughput rate through manufacturing facilities. Establishing an enterprise energy management program helps align throughput-driven process controls with measurable performance targets.

• Varying demands, and the need to maintain level or full state for water or fuel reservoirs, feed or coal bins, etc.

• Coordination: Organizing or sequencing multiple processes in a logical and efficient manner is an important aspect of automatic control applications.

• Automation: Human beings can make very good manual controllers because we can think on our feet and consider many variables together, but most control tasks are repetitive and suitable for mechanization. Introductory references explaining what building automation is clarify how routine tasks are delegated to algorithms while operators focus on exceptions.

Automatic operation allows people to provide oversight of advanced energy management system operations and more effectively utilize their time.

• Consistency: Manual control by people can be effective, although we are not all that repeatable and are sometimes forgetful. Using machinery for automatic control adds the improvement of consistent, repeatable operations. The repeatability and consistency feature of automatic control is very important in manufacturing.

• Conservation: Supplemental enhancement control routines can be incorporated to reduce energy use while still maintaining good control. It is important to note that control systems do not necessarily reduce energy consumption unless specifically applied and designed for that purpose.

Advanced energy management automatic controls are useful for basic regulation and quality control of processes and environments. They can also be leveraged for energy savings through optimization. Properly applied, these energy management systems are reliable and cost effective.

From: Energy Management Handbook, 7th Edition, The Fairmont Press

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Building automation system integrates electrical controls for HVAC, lighting, and power distribution, using BMS platforms, PLCs, BACnet/Modbus protocols, IoT sensors, and SCADA to optimize energy management, demand response, safety, and predictive maintenance.

What Is a Building Automation System?

An electrical control system automating HVAC, lighting, and power to improve efficiency, safety, reliability, and uptime.

✅ Integrates PLCs, sensors, VFDs, and switchgear controls

✅ Uses BACnet/Modbus for HVAC, lighting, and metering

✅ Enables energy analytics, demand response, fault diagnostics

In an era of rapidly evolving technology, smart buildings have become crucial to modern infrastructure. With the advent of the Internet of Things (IoT), facility managers are increasingly adopting advanced systems to monitor and control various parts of a building's performance. One such solution is the Building Automation System (BAS), which focuses on improving energy efficiency and occupant comfort and reducing maintenance costs. For an overview of foundational concepts, resources like what is building automation can help contextualize these systems for stakeholders.

The primary purpose of a building automation system is to streamline the operation and management of a building's critical subsystems, such as Heating, Ventilation, Air Conditioning (HVAC), lighting, security, and energy management. In addition, a centralized control platform enables facility managers to optimize resource utilization and respond to changing conditions more effectively. To understand device-level orchestration, guidance on energy management controls clarifies how setpoints and schedules are coordinated across platforms.

A typical BAS comprises three main components: input, controller, and output. Input devices like sensors to measure environmental parameters like temperature, humidity, and light levels. Controllers process this information and use pre-defined algorithms to determine the best action. Output devices, including actuators and relays, then implement these decisions by adjusting various systems, such as modifying the temperature in an HVAC system.

In practice, the data path often feeds into building energy management systems that aggregate trends for analytics and reporting.

There are numerous benefits to implementing a building automation system. First and foremost, it can significantly improve energy efficiency. By monitoring and controlling various systems, including HVAC, lighting, and energy management, a building automation system can ensure that resources are only used when necessary, leading to substantial cost savings. Moreover, intelligent building control system algorithms can identify inefficiencies and take corrective action, enhancing overall performance. When paired with disciplined energy management practices, these optimizations translate directly into measurable Key Performance Indicators.

In addition to improving energy efficiency, a BAS also enhances occupant comfort. By monitoring environmental factors like temperature, humidity, and air quality, the system can always maintain optimal conditions for occupants. Furthermore, many systems allow users to customize their preferences via a user interface, empowering them to create a comfortable environment suited to their needs. Organizations that formalize a energy management program often align comfort objectives with operational targets more consistently.

Another significant advantage of a BAS is its ability to integrate with IoT devices. As the IoT ecosystem expands, more devices and sensors are being developed, providing valuable data for building management. By incorporating this information into the building automation system, facility managers can gain deeper insights into building performance and make more informed decisions. This increasingly connected architecture enables advanced energy management workflows that leverage predictive models and fault detection for continuous improvement.

A wide range of building automation control systems is available on the market, catering to different needs and budgets. These include Energy Management Systems (EMS), which focus specifically on monitoring and controlling energy usage, and Building Management Systems (BMS), which offer a more comprehensive integration of various subsystems. In addition, some solutions provide systems integration capabilities, enabling facility managers to combine multiple systems under a user interface. Choosing among various energy management systems requires assessing scalability, interoperability, and cybersecurity posture for long-term success.

As technology continues to evolve, so will the capabilities of building automation systems. From advanced HVAC control to robust security systems and energy management solutions, a building automation system can potentially transform how buildings are managed and maintained. By implementing these systems, facility managers can achieve significant cost savings, improve occupant comfort, and contribute to a more sustainable future.

A building automation system is essential for modern facility management. They provide centralized control over various subsystems, improving energy savings and efficiency, occupant comfort, and reducing maintenance costs. Furthermore, as the IoT ecosystem expands, these systems are set to become even more powerful, offering deeper insights and more advanced control over building performance. So whether you are a facility manager looking to optimize your existing infrastructure or an architect designing the next generation of smart buildings, embracing the potential of building automation systems will undoubtedly lead to a more efficient and sustainable future.

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Industrial automation communication connects PLCs, sensors, drives, and SCADA via protocols like PROFINET, Modbus, OPC UA, and Ethernet/IP, enabling deterministic control, interoperability, diagnostics, safety, and IIoT data across electrical systems and networks.

What Is Industrial Automation Communication?

Networked real-time data exchange between PLCs, sensors, HMIs, and SCADA using standardized industrial protocols.

✅ Supports deterministic Ethernet (TSN) and legacy fieldbus integration

✅ Enables real-time control, diagnostics, and predictive maintenance

✅ Interoperates via PROFINET, Modbus, EtherNet/IP, and OPC UA

In the early 20th century, process control systems and the manufacturing systems were designed based primarily on the mechanical technology and with analog devices. After the period, the pneumatic control technology and the hydraulic power were introduced. The pneumatic control technology made it possible to control remote systems by a centralized control system. These technologies are still very common.

At the beginning of 1960, a digital computer was for the first time really applied as a digital controller. The term direct digital control (DDC) was used to emphasize that the computer directly controls the process. In the 1960s, the application of a minicomputer was still a fairly expensive solution for many control problems. In the meantime, programmable logic controller (PLC) was developed and it replaced the conventional, relay-based controller, having relatively limited control functions. In addition, many technologies were developed for machine tools and discrete production processes. The numerically controlled (NC) machine tool became to be controlled by computers and the robot was developed in this period.

With the more widespread use of digital computers and the associated technologies, industrial communication networks became to be developed with or converted to digital transmission. Proprietary digital communication networks for industrial use started in the 1960s as computers for automation systems were first linked together.

In mid 70s, the first distributed computer control system (DCCS) was announced by Honeywell as a hierarchical control system with a large number of microprocessors. Since its introduction in mid 1970s, the concept of the DCCS spread widely in many industrial automation systems such as power plant control systems, manufacturing systems, etc. The installation of distributed control systems in the newly planned plants or replacement of existing analogue or centralized control systems is presently a common decision of enterprise management. In sectors like power generation, advanced energy management strategies leverage DCS data to optimize load balancing and maintenance planning across units.

The use of local area networks to interconnect computers and automation devices within an industrial automation system has become popular since 1980. The high capacity low cost communication offered by local area networks has made distributed computing a reality, and many automation services. The 

As deployments expanded, many organizations realized that the benefits of industrial networks include lower downtime, scalable integration, and improved data visibility across operations.

industrial automation systems are often implemented as an open distributed architecture with communication over digital communication networks. Achieving high availability requires the right mix of industrial network components such as managed switches, protocol gateways, and ruggedized edge controllers.

It is now common for users connected to a local area network to communicate with computers or automation devices on other local area networks via gateways linked by a wide area network. Similar architectures now extend into transportation, where smart city automated level crossings depend on resilient networking to coordinate sensors, barriers, and central oversight.

As the industrial automation systems becomes large and the number of automation devices increases, it has become very important for industrial automation to provide standards which make it possible to interconnect many different automation devices in a standard way. Considerable international standardization efforts have been made in the area of local area networks. The Open Systems Interconnection (OSI) standards permit any pair of automation devices to communicate reliably regardless of the manufacturer. To plan these interoperable systems, designers often reference hierarchical levels in industrial networks to align plant-floor operations with supervisory and enterprise layers.

Industrial networks span many manufacturing applications. Standard industrial networks using digital communication technologies cover a wide range of manufacturing applications. In many applications, the types of devices and performance determine the type of network. Contrast the needs of two devices -- a proximity sensor used on a conveyor belt compared to a control valve used in a petroleum refinery. The proximity sensor has a single function - to transmit a Boolean on/off signal indicating the proximity of an object. We can accommodate this signal in a few bits of data. Diagnostic information from the sensor is probably limited to a single "health" indicator, which again requires very little data. However, we can expect the control valve to provide very sophisticated control functions and diagnostics, such as number of cycles since last servicing, packing friction, and ambient operating temperature. These parameters can be extremely critical in an environment such as a refinery -- failures can result in dangerous situations and costly downtime. Clearly, the proximity sensor and the control valve have different network requirements. Therefore, different types of industrial networks must address a variety of different needs. We must select the right network to address our specific application requirements.

What is an Industrial Network? By definition, an industrial network requires geographical distribution of the physical measurement I/O and sensors or functional distribution of applications. Most industrial networks transfer bits of information serially. Serial data transfer has the advantage of requiring only a limited number of wires to exchange data between devices. With fewer wires, we can send information over greater distances. Because industrial networks work with several devices on the same line, it is easier to add a new device to existing systems. Comparing fieldbus, Ethernet, and wireless backbones, understanding transmission methods in industrial networks helps engineers match latency, bandwidth, and environmental constraints.

To make all this work, our network must define a set of rules -- a communication protocol -- to determine how information flows on the network of devices, controllers, PCs, and so on. With improved communication protocols, it is now possible to reduce the time needed for the transfer, ensure better data protection, and guarantee time synchronization, and real-time deterministic response in some applications. Industrial networks also ensure that the system sends information reliably without errors and securely between nodes on the network.

For the lower level communication network for industrial automation, the industrial local area network solutions such as MAP are too expensive and/or do not reach the required short response times, depending on the application. The fieldbuses have been, therefore, developed to meet these requirements, and many efforts are now being made to make fieldbus standards for industrial automation applications. The same field-level connectivity principles underpin a modern building automation system where HVAC, lighting, and security integrate reliably across facilities.

Read More: Hierarchical Levels in Industrial Communication Networks

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