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Smart city automated level crossings integrate IoT sensors, AI, and V2X to optimize traffic management, enhance rail safety, enable predictive maintenance, and deliver real-time monitoring via 5G, edge computing, and SCADA platforms.

What Are Smart City Automated Level Crossings?

Systems using IoT, AI, and sensors to automate rail-road gates, boost safety, reduce delays, and optimize city traffic.

✅ Adaptive control via AI, V2X, and edge analytics

✅ Integrated SCADA with remote monitoring and diagnostics

✅ Fail-safe design with SIL-rated controllers and redundant sensors

Around the world, railway tracks pass through villages, towns, cities and metropolises which creates the problem of ubiquitous Level Crossings as they transect roads, highways, etc. The real-time train data, collected through Global Positioning System (GPS) satellites can be used to calculate critical distance to a level crossing. A sensor (receiver) keeps polling the approaching train data and actuates a motor that closes the gate of an unmanned LC.

Case Study – Indian Railways and problems with its LCs

Since the past few years, Indian Railways (IR) has been making strides in the realm of digital technology. Being the largest employer in the world, means managing a mammoth workforce and movement of passengers every day, equal to the population of Australia. Unfortunately, this includes running trains and transporting goods on a stagnated infrastructure of railroads. Both manned and unmanned Level Crossings, cause several accidents. The manned LCs, that have an operator, to pull the gate, are unreliable and often lead to delays for public, that wants to get from one side of the railway track to another.

Solution - Data from satellites

Taking advantages of advancements made in the field of satellite communications technology, Indian Railways has started using Global Positioning System data for running its trains. It collects the actual data as received from the satellites and links it to mobile phone applications and its web portal where travelers can find the running status of a train, they are interested in. This gives any user, information, such as speed, last station passed, time to reach the selected destination (approx.) and whether if the train is running late or at the right time.

Building Blocks of the proposed system – PLC and its FBD

A Programmable Logic Controller, or PLC, Fig. 1, is like a mini computer used for industrial automation everywhere around us. These controllers can automate a specific process, machine function, or even an entire production line. They can be made to calculate positions and take actions based on the status. The PLC receives information from connected sensors or input devices (thru the Input Modules), processes the data (in its Processor), and triggers outputs (connected to the Output Module) based on pre-programmed parameters. Depending on the inputs and outputs, a PLC can monitor and record run-time data, automatically start and stop processes, generate alarms if a machine malfunctions, and more. Programmable Logic Controllers are a flexible and robust control solution, adaptable to almost any application. For field deployments, reliable controller-network interoperability relies on industrial automation communication standards that govern data exchange between sensors, PLCs, and supervisory systems.

Fig. 1 - A Programmable Logic Controller consisting of a Power Supply, CPU and input and output modules.

Modern PLCs are programmed using Functional Block Diagram (FBD). They were introduced by IEC 61131-3 to overcome the weaknesses associated with textual programming and ladder diagrams. An FBD network, Fig. 2, primarily comprises interconnected functions and function blocks to express system behavior. Function blocks were introduced to address the need to reuse common tasks such as AND gate, OR gate, counters, and timers at different parts of an application or in different projects. A function block is a packaged element of software that describes the behavior of data, a data structure and an external interface defined as a set of input and output parameters. A function block is depicted as a rectangular block with inputs entering from the left and outputs exiting on the right. Key features of function blocks are data preservation between executions, encapsulation, and information hiding. Engineering teams can accelerate safe commissioning by leveraging PLC training courses that focus on FBD practices, diagnostics, and lifecycle maintenance.

An FBD is a program constructed by connecting multiple functions and function blocks resulting in one block that becomes the input for the next. Unlike textual programming, no variables are necessary to pass data from one subroutine to another because the wires connecting different blocks automatically encapsulate and transfer data.

A function block is not evaluated unless all inputs that come from other elements are available. When a function block executes, it evaluates all its variables, including input and internal variables as well as output variables. During its execution, the algorithm creates new values for the output and internal variables. Outputs of function blocks are updated because of function block evaluations. Changes of signal states and values therefore naturally propagate from left to right across the FBD network.

Fig. 2 - Functional Block Diagram (FBD) used to program a PLC. Complex mathematic operations are performed by simple functions in steps, deriving outputs from one or multiple inputs.

Automated LCs

The GPS data collected from satellites can be used for supplementary applications using simple systems integration technologies to improve a city’s infrastructure. In municipal deployments, integrating these feeds with a building automation system enables coordinated signaling, energy use, and roadway messaging across adjacent facilities.

The LC has a sensor (receiver) which keeps polling the approaching train data continuously from the satellites. The receiver sends this information to a Programmable Logic Controller, which calculates the "critical distance to the crossing" (difference, based on coordinates) The FBD can be designed using a comparator that compares real time position input to a pre-set value (say 300 ft.). It shall then proceed to calculate the difference of these 2 values. If this value is zero, then the output should become 1, which means that the train is now in the crossing envelope and the gates need to be shut. This output feeds the motor starting circuit. An important thing to note here are the factors influencing this calculation such as, the speed of the train and its distance away from the crossing envelope. Another parameter affecting this calculation is the width of the road, across the railway track. For wider roads, crossing envelope is more, on both sides of the road, which leads to the crossing envelope’s pre-set value to be more (than 300 ft.). While for narrow roads the crossing envelope pre-set value can be set to a lesser margin (less than 300 ft).

Making use of the several digital outputs available at the output module of the PLC, extra functionalities that can be added to the PLC circuit may include a horn sound, to alert the public near the crossing and a stop (RED) or go (GREEN) light. The power supply for this system is derived from Uninterruptible Power Supply (UPS) system with a battery unit, See Fig. 3. Integrating the UPS and load profiles into an advanced energy management strategy can optimize battery sizing, charging windows, and lifecycle costs.

Fig. 3 – GPS based Automated Level Crossing for Railroads

As the train, approaches the crossing, the gate will be closed, stopping the traffic on the road, until the train has moved away from the crossing envelope on the other side of the road.

When the train has gone out of the critical distance, using real time polling from GPS, the PLC will run its FBD again. The FBD will now not have a zero output but a positive value as the difference of the pre-set value (300 ft. in our example) and the current coordinates of the train is a positive number. After running this sequence for 2 minutes, and finding a positive number in the output of the FBD, it can open the gate by reversing the motor. This restores movement of road traffic.

Have more data? Use it for automation

The PLC can be programmed to detect and transmit alarms for faults in cases such as when the Motor does not start or the Battery units are low on the charge and need replacement. During such situations, PLC can send this information thru a wireless signal to the nearest control center, Fig.3. A Rail Infrastructure Operations & Maintenance (O&M) app or website could collect all this data and send out maintenance personnel to look after the equipment periodically thereby enhancing the life of the LC unit. A Central Control Operator (CCO) screen, Fig. 4, can display erroneous behavior of any equipment. The development of interface between the PLC and CCO requires detailed engineering and sound knowledge of communications. Choice of media and protocols should consider the available transmission methods in industrial networks to balance latency, range, and resiliency.

Fig. 4 – A sample Central Control operator screen shows the health of all the equipment. It is very important to keep monitoring the real-time status of critical infrastructure so necessary action can be taken subsequently.

At the control-center side, architects should map data paths to the hierarchical levels of industrial networks so alarms, control, and historian traffic are segregated appropriately.

Advantages aplenty

Railway Operators have a responsibility towards everyone, from the travelers on the trains and stations to people using its infrastructure elsewhere. Automated LCs will prevent accidents. This system is faster, as often guards at LC tend to shut the gates 10 to 15 minutes before the approach of the train, causing loss of valuable time of the public. Being a satellite based system, it is bound to be very precise and accurate. It will also save money as the need for guards to be present at such crossings will be eliminated. Beyond safety, standardized connectivity delivers measurable ROI through the benefits of industry networks such as improved uptime, easier scaling, and vendor interoperability.

Way forward

As various Railway Operators around the globe, look for ways to keep themselves functional and profitable, all railway crossings should be converted to automatic type, removing the need for a guard to be present 24x7. This solution can be a lynchpin to a digital revolution. Within a city’s limits, such automated LCs will enable transition towards a smart city and smart transport initiatives. Railway Operators must realize the importance of the data that they generate and put it to several innovative uses that makes people’s life easy.

Kshitij Saxena received his BTech in electrical and electronics engineering from Vellore Institute of Technology (2008) and MS in electrical engineering from University of Southern California (2010).

                He is currently working as a Senior Traction Power Engineer at WSP Oakland, USA. Previously he has worked with Bombardier Transportation and Pennsylvania Transformer Tech Inc.

                Mr. Saxena is an Engineer in Training from Pennsylvania and is a PMP. He’s passionate about Mass Transit & Renewable Energy.

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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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PLC training courses build automation skills in ladder logic, SCADA, HMI, and motion control, with hands-on programming on Siemens and Allen-Bradley platforms, diagnostics, IEC 61131-3 standards, safety, and commissioning best practices.

What Are PLC Training Courses?

Programs teaching PLC programming, SCADA, HMI, and industrial automation with hands-on labs and commissioning.

✅ Ladder logic, function blocks, and IEC 61131-3 programming

✅ Siemens TIA Portal and Allen-Bradley RSLogix labs

✅ Fault finding, I/O wiring, safety, and commissioning

Our PLC training courses are designed to help students keep abreast of the latest PLC technologies and techniques available for industrial automation. These courses offer an excellent opportunity for students to ask specific questions and exchange ideas relating to their own applications. For context on modern plant connectivity, see the overview of industrial automation communication standards used in training.

Our PLC training courses are intended for experienced users and will give them greater knowledge of enhanced PLC functionality. Participants also review the benefits of industry networks to understand how network design impacts reliability.

We have three PLC training courses:

Before selecting a pathway, it helps to understand the hierarchical levels of industrial networks that underpin PLC architectures.

PLC Basics Training

PLC Training Basic - Our 12-Hour (2-Day) live online instructor-led industrial automation course is designed to instruct electrical control professionals on how to successfully integrate a PLCs into actual day-to-day industrial electrical processes. The course not only deals with the hardware and software, but all the surrounding systems that must be compatible to achieve a safe and reliable control system. This PLC Training Basic course is generic in nature and applies to all PLC types and manufacturers. We also examine key industrial network components so attendees can better integrate field devices.

PLC Training - Intermediate

PLC Training - Intermediate - Our 12-Hour (2-Day) live online instructor-led industrial automation course is designed to instruct electrical control professionals on how to successfully integrate a PLC into actual day-to-day industrial electrical processes. It not only deals with the hardware and software, but all the surrounding systems that must be compatible to achieve a safe and reliable control system.  The curriculum compares common transmission methods in industrial networks to guide protocol selection.

PLC Training Course - Advanced

In the advanced module, we connect control strategies to advanced energy management concepts for measurable performance gains.

Our 12-Hour (2-Day )Advanced PLC Training Course is designed to give students a basic understanding of Programmable Logic Controllers and how PLCs function. This Advanced PLC training course will not make students PLC experts but rather give them a basic understanding of the PLC, the PLC’s functionality and limitations. The PLC training seminar is generic in nature and applies to all types and manufacturers. Case studies include applications like smart city automated level crossings where safety and uptime are critical.

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Energy management enhances power systems via smart grid controls, demand response, load forecasting, SCADA, and IoT sensors to improve energy efficiency, peak shaving, power quality, and renewable integration across industrial and utility operations.

What Is Energy Management?

Energy management is the control of electrical loads and assets to optimize efficiency, reliability and cost.

✅ Predictive load forecasting and peak shaving strategies

✅ SCADA/EMS integration with IoT sensors and analytics

✅ Demand response, power quality, and DER coordination

Energy management (EM) is a crucial practice today, as it helps businesses and individuals reduce their carbon footprint, save money, and contribute to a more sustainable future. By incorporating key elements such as efficiency, demand response, building automation, audits, smart grid technology, HVAC optimization, conservation, renewable energy, monitoring, and analytics, a comprehensive EM program can lead to significant savings and environmental benefits. As the world continues to face the challenges of climate change and dwindling resources, EM will remain an indispensable tool for creating a more sustainable and efficient future. For organizations starting out, an energy management program can provide a structured roadmap for setting goals and tracking performance.

Energy management is crucial for several reasons. First, it helps reduce carbon emissions and the overall environmental impact of energy use. Second, it saves money by lowering costs and making facilities more energy efficient. Third, EM practices contribute to businesses and organizations' long-term sustainability and competitiveness. Modern energy management systems offer centralized dashboards and automated alerts that help sustain these gains over time.

Building automation is one of the primary ways energy management systems improve efficiency in buildings. These systems utilize sophisticated technology to control and optimize energy use in various systems, such as heating, ventilation, air conditioning (HVAC), lighting, and security. By automating these systems, buildings can operate more efficiently and effectively, reducing waste and saving on costs. For broader context, guides on building automation fundamentals can help teams understand integration points with HVAC and lighting controls.

Energy management in industrial facilities requires a combination of best practices, including implementing EM systems, regular audits, and data analytics. By monitoring and analyzing data, asset managers can identify areas of inefficiency, implement targeted improvements, and track the success of their energy management strategies. As operations mature, adopting advanced energy management practices can unify analytics, forecasting, and optimization across multiple facilities.

Renewable energy sources, such as solar, wind, and geothermal, can be integrated into energy management systems to improve sustainability further and reduce reliance on fossil fuels. For example, a facility may use solar panels to generate electricity during peak sunlight hours, reducing the need for grid-supplied energy and reduce energy costs. Additionally, renewable energy can be used with energy storage systems to provide backup power during high demand or grid outages. Well-designed building energy management systems coordinate on-site renewables with storage and loads to maximize self-consumption and resilience.

An effective EM strategy comprises several key components, including a thorough understanding of use, a commitment to continuous improvement, and a focus on energy-efficient technologies and practices. For example, businesses can implement energy-saving measures, such as retrofitting lighting systems with energy-efficient LEDs, upgrading HVAC systems to more efficient models, and improving building insulation to minimize heat loss. Upgraded energy management controls enable granular scheduling, sensor-driven setpoints, and measurement and verification to prove savings.

Smart grids and demand response play a critical role in EM by enabling a more flexible and responsive approach. Smart grids use advanced technology and real-time data to optimize electricity generation, distribution, and energy consumption. On the other hand, demand response programs incentivize consumers to reduce or shift their energy use during periods of high demand, helping to balance the grid and lower overall costs. When paired with a capable building automation system, demand response signals can trigger coordinated load shifts with minimal occupant disruption.

Audits are an essential part of energy management, as they provide a comprehensive assessment of a building's performance and identify opportunities for improvement. During an audit, an EM professional evaluates the consumption of a facility, typically an office building or industrial plant, and recommends cost-effective measures to reduce use and costs. These recommendations may include upgrading equipment, implementing energy-efficient practices, and addressing inefficiencies in the building's design or operations.

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Benefits of industry networks include collaboration, knowledge sharing, standards alignment, and vendor partnerships that accelerate innovation in electrical engineering, grid modernization, smart manufacturing, and safety compliance across power systems and automation ecosystems.

What Are the Benefits of Industry Networks?

They enable faster innovation, standards compliance, risk mitigation, and scalable solutions through shared expertise.

✅ Accelerates compliance with IEEE, IEC, UL standards and codes

✅ Improves interoperability across SCADA, PLC, and smart grid systems

✅ Enables supplier benchmarking, risk sharing, and joint R&D

Modern control and business systems require open, digital communications. Industrial networks replace conventional point-to-point RS-232, RS-485, and 4-20 mA wiring between existing measurement devices and automation systems with an all-digital, 2-way communication network. Industrial networking technology offers several major improvements over existing systems. With industry-standard networks, we can select the right instrument and system for the job regardless of the control system manufacturer. Other benefits include:

To understand how device-level buses, controllers, and enterprise systems coordinate, resources like industrial automation communication outline protocol choices, latency tradeoffs, and integration patterns. Selecting between Ethernet, fieldbus, and wireless options benefits from comparing transmission methods for industrial networks with respect to determinism, noise immunity, and distance.

• Reduced wiring -- resulting in lower overall installation and maintenance costs
• Intelligent devices -- leading to higher performance and increased functionality such as advanced diagnostics
• Distributed control -- with intelligent devices providing the flexibility to apply control either centrally or distributed for improved performance and reliability
• Simplified wiring of a new installation, resulting in fewer, simpler drawings and overall reduced control system engineering costs
• Lower installation costs for wiring, marshalling, and junction boxes

Delivering these benefits also depends on choosing switches, gateways, and physical media from a well-architected set of industrial network components that match environmental and reliability requirements. Designers often map sensors, controllers, and supervisory systems across the hierarchical levels of industrial networks to balance real-time control with plantwide visibility.

Standard industrial networks offer the capability to meet the expanding needs of manufacturing operations of all sizes. As our measurement and automation system needs grow, industrial networks provide an industry-standard, open infrastructure to add new capabilities to meet increasing manufacturing and production needs. For relatively low initial investments, we can install small computer-based measurement and automation systems that are compatible with large-scale and long-term plant control and business systems. This standards-based approach aligns closely with how a building automation system aggregates HVAC, power, and security data for unified operations. For teams expanding beyond production into facilities integration, understanding what building automation entails helps frame networking requirements and data governance.

As energy costs and sustainability goals rise, leveraging advanced energy management over the same industrial network can drive measurable efficiency gains and carbon reporting accuracy.

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