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System integration for process automation promoted the technologies that were accessed to functions and data of field device, controller, and SCADA system. In addition, the data from filed devices can apply to solve device diagnostic and preventive maintenance. This paper describes the practical technique to configure and implement of control and SCADA system that focus on integration of field device, PLC controller, and SCADA system. The paper presents case study of Allen-Bradley (AB) PLC by using WirelessHART device to temperature control and device diagnostic through SCADA system. PLC’s input/output (I/O) modules are installed that consists of Modbus module, digital I/O module, analog I/O module. In addition, Prosoft configuration builder and Studio 5000 software are new software to build add on Modbus instruction and ladder diagrams, respectively. The experiments perform in case study of temperature control by using Proportional–Integral–Derivative (PID) function in the AB PLC. Wonderware InTouch SCADA software is implemented to monitor the process mimic, trend, and alarm. Moreover, the technique can support the operators and engineers to make decision for process control and devices diagnostic.

At this time, traffic congestion is a problem that many big cities face, especially at intersections. Traffic jams at intersections occur a lot because they are caused by the traffic light regulation system that is not in accordance with the traffic light settings which can be changed at any time. The design of the traffic light simulation control program is deviated by four. The program is made with 4 models, namely the all-light flashing model, the flashing yellow light model, and a different one-way model. The current traffic light regulation mostly uses a fixed time setting system where the lights are set to work on a fixed time basis, regardless of the ups and downs of traffic flow. Therefore, offered a detector system (traffic actuated) by utilizing PLC (programmeble logic controller) as a controller. This research is made a simulation tool with PLC Omron. The working process of this tool is in the form of sending input from sensors installed on the road, where this sensor detects the presence or absence of vehicles.

A miniature conveyor machine assisted by embedded systems and controlled by a programmable logic controller (PLC) has been fabricated with the operating mechanism is based on the detection of two different colors. The objectives of this research are to obtain a miniature machine is controlled by the PLC system, create a ladder diagram-based program structure, and measure the performance of the embedded system. Obtaining the machine is carried out through assembly of the conveyor frame, installation of all devices, and integrated wiring. The programming for the Omron PLC system is based on providing the CX-Programmer 64 bits, establishing algorithms and compiling ladder diagrams, and compiling and uploading processes. The performance measurement includes synchronization conditions between the simulator and the control system, observations of the readings of installed sensors for activating all devices on the output side, and observing the measurement of the filling process time and the installation of bottle caps assisted by the pneumatic system. The results of the performance during the process of filling and installing the lid obtained a success rate of 75%, based on four trials, three successes, and one failure. The general conclusion is that the embedded system that has been built can be used as a simulator for the mechanism of filling liquid into bottles and installing bottle caps, and it is as an implementation of instrumentation and automation processes. &nbsp, Telah dihasilkan sebuah miniatur mesin konveyor berbantuan sistem tertanam terkendali oleh programmable logic controller (PLC) dengan mekanisme operasi mesin berdasarkan kepada deteksi terhadap dua warna berbeda. Tujuan penelitian ini berupa memperoleh sebuah miniatur mesin terkendali oleh sistem PLC, membuat struktur program berbasis ladder diagram, dan mengukur kinerja sistem tertanam. Perolehan mesin dilakukan melalui perakitan kerangka konveyor, pemasangan seluruh perangkat, dan pengawatan terintegrasi. Metode pemrograman terhadap sistem PLC Omron didasarkan kepada penyediaan CX Programmer 64 bit, penetapan algoritma dan penyusunan ladder diagram, dan proses compiling dan uploading. Pengukuran kinerja meliputi kondisi sinkronisasi antara simulator dan sistem kontrol, pengamatan terhadap pembacaan sensor-sensor terpasang untuk pengaktifan seluruh perangkat di sisi keluaran, dan pengamatan terhadap pengukuran waktu proses pengisian dan pemasangan tutup botol berbantuan sistem pneumatic. Hasil kinerja saat proses pengisian dan pemasangan tutup diperoleh tingkat keberhasilan sebesar 75%, berdasarkan empat kali uji coba, tiga kali berhasil dan satu kali gagal. Kesimpulan secara umum, bahwa sistem tertanam yang telah dibangun dapat digunakan sebagai simulator untuk mekanisme pengisian cairan ke dalam botol dan pemasangan tutup botol, dan hal itu sebagai implementasi terhadap instrumentasi dan proses otomasi.

Cilj rada je bio opisati od kojih dijelova se sastoji korištena maketa koja sadrži programabilni logički kontroler Mitsubishi FX5UC i pripadne module. Nakon što su opisani svi dijelovi PLC-a potrebno je bilo objasniti različite načine upravljanja sustavom te implementirati algoritme za upravljanje PLC-om. Prikazano je kako se uz pomoć PLC-a mogu automatizirati procesi. Na kraju rada se demonstrirao rad PLC-a kroz konkretne primjere pomoću pokusa za regulaciju temperature u komori, upravljanje brzinom vrtnje asinkronog motora i upravljanje servomotorom. The aim of the paper was to describe all the parts the used model consists of, which contains a programmable logic controller Mitsubishi FX5UC and associated modules. After all parts of the PLC were described, it was necessary to explain the different ways of managing the system and to implement algorithms for PLC management. It is shown how processes can be automated with the help of a PLC. At the end of paper, the operation of the PLC was demonstrated through concrete examples using experiments for chamber temperature control, asynchronous motor speed control and servomotor control.

A PLC-based embedded device on a miniature conveyor machine for operating a rejection system has been designed and constructed. The research objectives, namely (i) design and manufacture of an integrated system, (ii) making program structure based on a ladder diagram, and (iii) measuring the performance of an integrated system. Integrated system assembled from a miniature of the conveyor machines and belt installation, and installing the dc motor, while the rejection system assembly by placing several sensors, installing stepper motor, and wiring to the PLC system. Programming based on ladder diagram carried out by determining algorithms, compiling the ladder diagram, addressing the input/output, and compiling and uploading the program from PC to PLC. The performance of the integrated system was observed when (a) observation during synchronization, (b) observations of sensor readings while the rejection system simulator is operating, and (c) observation and measurement of the processing time of the rejection arm. Overall results have been obtained in the form of a PLC-based embedded device for the rejection system simulator on observations of the condition of the bottle caps for beverage packaging. Based on the overall observation, the PLC-based embedded device has functioned to operate the rejection system can be implemented at a manufacturing scale. &nbsp, Telah dirancang dan dikonstruksi sebuah embedded device berbasis PLC pada miniatur mesin konveyor untuk pengoperasian simulator sistem rejection. Tujuan penelitian ini, yaitu (i) merancang dan membuat sistem terintegrasi, (ii) membuat struktur program berbasis ladder diagram, dan (iii) mengukur kinerja sistem terintegrasi. Sistem terintegrasi dirakit dari miniatur mesin konveyor dengan pemasangan belt dan motor dc, sedangkan sistem rejection dirakit melalui penempatan sejumlah sensor, pemasangan motor stepper, dan perkabelan pada sistem PLC. Pemrograman berbasis ladder diagram, dilakukan melalui penentuan algoritma, penyusunan ladder diagram, pengalamatan jalur masukan/keluaran, dan penyusunan dan pengunggahan program dari komputer personal ke PLC. Kinerja sistem terintegrasi diamati ketika (a) pengamatan selama sinkronisasi, (b) pengamatan pembacaan sensor saat simulator sistem rejection beroperasi, dan (c) pengamatan dan pengukuran waktu proses lengan rejection. Hasil keseluruhan telah diperoleh dalam bentuk embedded device berbasis PLC untuk simulator sistem rejection pada pengamatan terhadap kondisi tutup botol kemasan minuman. Berdasarkan pengamatan secara keseluruhan, perangkat tertanam berbasis PLC yang berfungsi untuk pengoperasian sistem rejection dapat diimplementasikan pada skala manufaktur.

Automotive Industries were aiming at building fully automated machines to obtain increased production without compromising in the quality of the product. Building an automatic machine is one of the most efficient technologies to overcome defects resulted due to trimming process of valve stem seals. The existing system includes semi-automatic machine with punching system results in improper trimming. Hence in order to reduce these defects the system aims at building an automatic trimming machine for valve stem seals used in vehicles. The semi-automatic machine was ended with few defects which affect the product quality. The customer satisfaction is an important factor for industry growth. The system focuses on building a simple machine and control panel design with Programmable Logic Controller (PLC) as the controller. PLC will be most suitable controllers for the automotive industries. PLC was programmed using the CX-Programmer software with ladder logic as the programming language. The operation of the results was also displayed using HMI (Human Machine Interface) screen, which will provide information to the operator about machine production and its status.

A PLC based simulator has been assembled for controlling road traffic at ship line crossings. The objectives of this study include (i) assembling a miniature bridge body, a lift-drop back mechanism for highway traffic at ship crossings, and an operating system based on a programmable logic controller (PLC) and (ii) measuring the performance of the operating system through its presence input-output signal. Assembly with the following stages: (i) implementation of miniature bridge construction; (ii) selection and placement of sensors; (iii) installation of pumps for hydraulic systems; (iv) installation of servo motor assisted latches; (v) installation of traffic control lights and indicators; and (vi) manufacture of operation panels, wiring, and installation of PLC systems. Mitsubishi PLC system programming is based on compiling algorithms and ladder diagrams with GX Works-2 32 bit. Performance measurement includes (i) when synchronization between the operating system and control on the PLC in the form of input from the operation panel and sensors on the input line are processed in the PLC program to produce an output in the form of appropriate and precise control, (ii) when the sensors installed in the system operation has functioned as programmed into the PLC, and (iii) during the process of lifting and lowering the miniature of the bridge body, there is a time difference of 26 seconds with the condition that the lifting time is longer than the time of lowering the miniature bridge body. The general conclusion is that the miniature of the bridge body and the operating system that has been built can be used as a simulator for the existence of a bridge that can be lifted and lowered again as a highway traffic lane at a ship crossing., Telah dirakit simulator berbasis PLC untuk pengaturan lalu-lintas jalan raya pada perlintasan jalur kapal. Tujuan penelitian ini meliputi (i) merakit miniatur badan jembatan, mekanisme pengangkatan-penurunan kembali untuk lalu-lintas jalan raya pada perlintasan kapal, dan sistem pengoperasian berbasis pengontrol logika terprogram atau Programmable Logic Controller (PLC) dan (ii) mengukur kinerja sistem pengoperasian melalui keberadaan sinyal masukan-keluaran. Perakitan dengan tahapan-tahapan: (i) pelaksanaan konstruksi miniatur jembatan; (ii) pemilihan dan penempatan sensor-sensor; (iii) pemasangan pompa untuk sistem hidrolik; (iv) pemasangan palang pintu berbantuan motor servo; (v) pemasangan lampu pengatur lalu lintas dan indikator; dan (vi) pembuatan panel operasi, pengawatan (wiring), dan pemasangan sistem PLC. Pemrograman sistem PLC Mitsubishi didasarkan pada penyusunan algoritma dan ladder diagram dengan GX Works-2 32 bit. Pengukuran kinerja meliputi (i) saat sinkronisasi antara sistem pengoperasian dan kontrol pada PLC berupa masukan dari panel pengoperasian dan sensor pada jalur masukan diproses dalam program PLC untuk dihasilkan keluaran berupa pengontrolan yang sesuai dan tepat, (ii) saat sensor-sensor yang terpasang pada sistem pengoperasian telah berfungsi sebagaimana telah diprogramkan ke dalam PLC, dan (iii) saat proses pengangkatan/penurunan miniature badan jembatan, terdapat selisih waktu sebesar 26 detik dengan kondisi, bahwa waktu pengangkatan lebih lama dibandingkan dengan waktu penurunan kembali miniatur badan jembatan. Kesimpulan secara umum, bahwa miniatur badan jembatan dan sistem pengoperasian yang telah dibangun dapat digunakan sebagai simulator keberadaan jembatan yang dapat diangkat dan diturunkan kembali sebagai jalur lalu-lintas jalan raya pada perlintasan kapal.

This study discusses how to design a programmable logic controller (PLC) simulator trainer that can work and simplify human work and fast production. The 3-phase motor control of the water pump machine in the block ice cube is used with the CP1E-N20DR-D Omron PLC with a ladder diagram program designed with the Cx-Programmer computer application, as well as the design of communication media between the machine and the operator using the Cx-Designer software. As for the input / output used, the input is in the form of a level sensor module, the level sensor functions as a liquid barrier 1 and 2. The output is in the form of water pumps 1 and 2, the AC motor functions as filling and forming block ice and moving the ice cubes. Based on the research results, the Trainer Module for this ice block molding simulator is composed of several components that describe the process of making ice cubes by using the appropriate input / output and can work in accordance with the prearranged job descriptions.

The need for automatic beverage vendors is quite high in public places and crowds, which will be more efficient and efficient than the beverage vendors who are human-friendly. This paper discusses the design of an automatic beverage vendor based on a programmable logic controller (PLC). The PLC used for this study is the production of Outseal, which has an Outseal Studio simulation program with a ladder diagram control. This automatic beverage vendor consists of input, process, and output. The primary input of this system is an infrared sensor, and a flow meter sensor to detect the cup's presence and how much juice poured to the cup. The DC motor and pump are the control output. A simulation program demonstrates the effectiveness of this automatic beverage supplier with the Outseal studio.

With the recent advancement in Industrial Internet of Things (IIoT), general programmable logic controllers (PLCs) have been playing more and more critical roles in industrial control systems (ICSs), such as providing local data processing, decentralized control and fault diagnosis. These so called edge-PLCs, directly receive the raw data from sensors embedded in factory equipments, put them into predefined memory space and perform analysis using programs such as the ladder logic. The challenge is how to allocate blocks in the fixed-size memory to different sensors so as to match irregular data flows. In this paper, we try to conduct performance analysis of different partition instances of the memory in the edge-PLC by modeling this problem as a multiple single-server queueing systems. We assume every sensing flow is independent of each other and has its dedicated processer. Changes can be made to partition instances to adapt to the external environment, such as the rising of order numbers or product category switching. Each state of the environment is defined by the finite state Markov chain and arrival of sensing data flows follow the stationary Poisson process. The data in the queue will expire after staying in the memory for a while. The duration of availability and service is modeled as the exponential distribution. The performance measured under different system states are analyzed in the simulation.

In this paper, we study the Gelfand–Cetlin systems and polytopes of the co-adjoint SO(n)-orbits. We describe the face structure of Gelfand–Cetlin polytopes and iterated bundle structure of Gelfand–Cetlin fibers in terms of combinatorics on the ladder diagrams. Using this description, we classify all Lagrangian fibers.

A typical example of discrete event systems (DESs) is a reconfigurable manufacturing system (RMS) whose can be changed and become more complicated during its operation. Thus, an effective tool needs to be developed to create both high- and low-level DES implementation. The ladder diagram (LD) is a common programming method for controlling DESs. Petri nets (PNs) represent the most important graphical and mathematical tool that can be used to provide an integrated solution for the design, modeling, analysis, control, and implementation of DESs. Various types of PN-based LDs are developed for DESs, which have high structural complexity of the LDs. Therefore, an approach that can facilitate the elimination of the LDs’ structural complexity needs to be developed. The main objective of this paper is to develop a two-step approach for LDs implementation for RMSs with dynamic changes. First, a colored resource-oriented Petri net (CROPN)-based algorithm is proposed for a rapid and valid configurations of an RMS. Second, a ladder diagram colored resource-oriented Petri net (LDCROPN) is developed to convert the CROPN into an LD. The developed approach is evaluated using examples in the literature. Moreover, the results demonstrate the effectiveness of the developed approach for LD implementation under RMS specification changes.

This account details the design and construction of a sophisticated tracking wheel for the accelerated aging of polymer insulators by subjecting them to surface contamination and high voltage. Automated control of wet-dry cycles is achieved by means of a computer-controlled lift mechanism that operates in tandem with the rotation. The applied voltage is continuously variable and can accommodate insulators of mixed lengths. The design incorporates a fail-safe control system that automates the selected test cycle, provides an intuitive user interface, and integrates multiple safety measures. This is achieved by implementing a programmable logic controller with digital and analog inputs and outputs. An associated ladder logic program automates the actuation of electromechanical hardware while also processing the inputs provided from control hardware, such as limit switches, optical encoders, variable frequency drives, and sensors. A touch-screen human interface module provides feedback and allows the user a means of input. Programmed fault detection, flood sensors, and a trapped key system increase the level of user safety and provide environmental and infrastructure protection.

Programmable Logic Controller (PLC) based process control automation projects are a multiphase task requiring months of planning, specification documentation, design, implementation, debugging, and final commissioning. Debugging real time process control implementation is a three-phase process; logic simulation debugging, field static checkout, and in plant final testing and tuning. This paper briefly discusses the fundamental techniques used in the first two stages of implemented ladder logic debugging [5, 6]. A wastewater treatment facility for the processing of high flow storm rainwater using the Allen Bradley (AB) SLC 500 PLC is used to illustrate the concepts discussed. The rainwater is channeled to two large wet wells, the east wet well and the west wet well. The water is pumped to the river from the two connected wells at constant rate using a predefined process sequence control. Pumping station with multi motors deriving constant speed immersed pumps are used to regulate the discharge water flow and the level in the two wells. Only two pumps are assumed here; one in the east wet well and the other in the west wet well. The motors provide an input discrete signal indicating if the motor is running or not. The motors can also start by activating the Push Button located on the local panel if the AUTO/MAN switch is in Manual. Three float switches are used to provide an accurate indication of the water level at three prespecified critical east / west wet well locations. The Low-Level Float switch triggers the stopping of the running pump. The High-level Float switch triggers the starting of the scheduled pump. If the scheduled pump fails to start within more than 5 seconds, a backup pump is selected and started (not shown in this paper). An alarm must be issued in order to alert the operator of any motor failure. The Very High-level float switch triggers the starting of both pumps. If either of the two pumps fails to start the corresponding alarm is activated by the control. Pumps are scheduled to run according to an operator pre-defined calendar. This input is expected in hours of accumulated total pump run time. The two pumps must alternate while the water level is below the Very High Level and above the Low Level. Cascaded timers are not altered during the time when the two pumps are running. This paper shows the static and simulation debugging an abbreviated version of the typical original system used in wastewater facilities.

Ladder Logics is a programming language standardized in IEC 61131-3 and widely used for programming industrial Programmable Logic Controllers (PLC). A PLC program consists of inputs (whose values are given at runtime by factory sensors), outputs (whose values are given at runtime to factory actuators), and the logical expressions computing output values from input values. Due to the graphical form of Ladder programs, and the amount of inputs and outputs in typical industrial programs, debugging such programs is time-consuming and error-prone. We present, in this paper, a Why3-based tool prototype we have implemented for automating the use of deductive verification in order to provide an easy-to-use and robust debugging tool for Ladder programmers., In Proceedings F-IDE 2019, arXiv:1912.09611

Robotic technologies are being used in various sectors for performing different tasks. In these technologies Pre defined actuator control programming techniques are used to perform desired tasks in the selected filed instead of human beings. But, Robotic control programming needs to be changed & reconfigured to change the control action & nature of working. So, there is no reliable technology to avoid reprogramming the robot. So, this paper presents development of artificial replicator to avoid reprogramming the robot for different situations, tasks such as bomb diffusion and sensitive surgery, taking readings from an active volcano or scientific analysis at radiation affected areas. In this proposed work, the wireless flexible gloves (emulator) are designed; which are integrated with flex, accelerometer, force, tilt, temperature sensors & also peltier modules and these sensors’s output are connected to Arduino board & calibrated into the real nature of signal using Arduino programming. This Arduino with Wi-Fi shield communication is used to interact wirelessly with replicator-Robot. The desired control actions are recommended to robot by emulator moments through wearing gloves. The movements of robot hand wrist, fingers, forearm, head, elbow and shoulder can be controlled by advanced version Fx-5U PLC(Programmable Logic Controller).This PLC has the feature of industry internet protocol so emulator can be easily communicated with robot. Melsoft GX-Works-3 programming software is being to develop the algorithm for manipulation of emulator commands to actuator control signals. Here PLC executes actuator control Ladder programming with the speed of 40ns.

The main components and features of a pumping station system are presented in this paper. Based on the formulated requirements, appropriate programmable logic controller and electric drive are selected. The respective input and output signals used are described and a control logic is synthesized. A reduced laboratory model of the pumping station has been developed, on which experimental studies have been carried out to verify the applied control approach.

In this paper, we discuss an approach which allows an attacker to modify the control logic program that runs in S7 PLCs in its high-level decompiled format. Our full attack-chain compromises the security measures of PLCs, retrieves the machine bytecode of the target device, and employs a decompiler to convert the stolen compiled bytecode (low-level) to its decompiled version (high-level) e.g. Ladder Diagram LAD. As the LAD code exposes the structure and semantics of the control logic, our attack also manipulates the LAD code based on the attacker’s understanding to the physical process causing abnormal behaviors of the system that we target. Finally, it converts the infected LAD code to its executable version i.e. machine bytecode that can run on the PLC using a compiler before pushing the malicious code back to the PLC. For a real scenario, we implemented our full attack-chain on a small industrial setting using real S7-300 PLCs, and built the database (for our decompiler and compiler) using 108 different control logic programs of varying complexity, ranging from simple programs consisting of a few instructions to more complex ones including multi functions, sub-functions and data blocks. We tested and evaluated the accuracy of our decompiler and compiler on 5 random programs written for real industrial applications. Our experimental results showed that an external adversary is able to infect S7 PLCs successfully. We eventually suggest some potential mitigation approaches to secure systems against such a threat.

Programmable logic controllers are commonly used in automation systems. Continuously growing demands result in the growth of control program complexity. The classic approach, based on programmatic serial-cyclic execution, results in an unacceptable extension of response time. To overcome long response time massive parallel program execution is proposed. It utilize direct in hardware program implementation in field programmable devices. The paper brings a formal method of representing control programs using flow graphs and enabling single cycle computations. The developed method accepts ladder diagrams (LD) and sequential function charts (SFC), according to IEC61131-3 standard requirements. It is capable of handling logic and arithmetic computations, enabling its hardware mapping. The intermediate form is optimized using flow graph representation and BDDs for analyzing logic dependencies. The BDD representation of logic dependencies enables direct mapping to lookup tables of a selected FPGA family. All the above steps deliver high-performance and direct hardware implementation of the control program given by standard languages. The controller response time is short, predictable, and independent from logic conditions during program execution.

Automated production systems (aPS) are highly customized systems that consist of hardware and software. Such aPS are controlled by a programmable logic controller (PLC), often in accordance with the IEC 61131-3 standard that divides system implementation into so-called program organization units (POUs) as the smallest software unit and is comprised of multiple textual and graphical programming languages that can be arbitrarily nested. A common practice during the development of such systems is reusing implementation artifacts by copying, pasting, and then modifying code. This approach is referred to as code cloning. It is used on a fine-granular level where a POU is cloned within a system variant. It is also applied on the coarse-granular system level, where the entire system is cloned and adapted to create a system variant, for example for another customer. This ad hoc practice for the development of variants is commonly referred to as clone-and-own. It allows the fast development of variants to meet varying customer requirements or altered regulatory guidelines. However, clone-and-own is a non-sustainable approach and does not scale with an increasing number of variants. It has a detrimental effect on the overall quality of a software system, such as the propagation of bugs to other variants, which harms maintenance. In order to support the effective development and maintenance of such systems, a detailed code clone analysis is required. On the one hand, an analysis of code clones within a variant (i.e., clone detection in the classical sense) supports experts in refactoring respective code into library components. On the other hand, an analysis of commonalities and differences between cloned variants (i.e., variability analysis) supports the maintenance and further reuse and facilitates the migration of variants into a software product line (SPL)., JSS: Special Issue on Clone Detection

The powerful advantages of programmable logic controller (PLC) dominate the process industries. Scan time of the PLC increases with the number of inputs, rungs added in ladder diagram (LD). Researchers have identified and proved that field programmable gate array (FPGA) is more suitable than PLC for high speed applications. PLC executes the instructions represented through LD. FPGA does not support LD. PLC programmers are not familiar with FPGA programming. This work has developed application software to generate equivalent VerilogHDL code for LD using LabVIEW. Novelty in this work is that each rung is defined using an "assign" statement to ensure concurrent execution of all the rungs. A data acquisition system was created to monitor the digital signals handled by the FPGA. The software was verified with a case study of substances mixing and traffic light control system.

During the maintenance of bearing, it is necessary to solve the disassembly problem of bearing seal covers. In order to improve the working efficiency, a new type of disassembly device of seal covers is designed, which includes three parts: disassembly device, compression device and electrical system. Using Verilog language programming, electrical control part is controlled by PLC. The ladder diagram is drawn by software Botu, and the logical diagram is built by QuartusI. Then the simulation analysis is did by ModelSim and get the waveform diagram. Finally, the Layout wiring diagram is obtained. It is proved that this kind of device can meet the needs of bearing disassembly and maintenance, and have certain application value.

This paper describes a smart parking system using the Ladder Diagram programming language that can be used by students to understand the principles of a process automation. It is an educational platform that gives information about what elements are part of such programs, how to implement them using a programmable logic controller, how to create a Logical Diagram / Organization Chart and simulate the program. This type of application approach fits well due to the reorganization of the educational teaching system that has been a great challenge for many teachers during the pandemic, not only regarding the teaching curriculum, but also regarding teaching methods. Also, because of the constantly growing digitalization, virtual laboratories and electronic learning platforms must become frequent teaching methods, especially in higher education systems.

PLC controllers in today's day are a staple mechanism to control operation of large number of machines and devices in the industry. With their advanced usage, it is increasingly becoming a staple and important part of Engineering. Thus, it is crucial that this knowledge is effectively delivered to students with practical applications. This paper presents a series of laboratory experiments for students to learn and explore the various industrial applications of PLC’s. The control problems in this paper are defined with respect to their applications in different industries such as automotive, steel, oil and electronics. Applications are typical processes that can be observed in these industries such as material conveying, material handling, cutting processes, system control and temperature control. All the problems are solved using Ladder Logic programming on Automation Studio to simulate these processes and provide students with a wholesome learning experience.

Implementation of digital sensor simulation concept for bowl cleaning machine using STL algorithm is presented in this paper. STL algorithm has been generated using three variables and is incorporated in the execution logic of the PLC for the bowl cleaning process. Digital sensors like proximity sensors and limit switches establishes closed loop control system, which governs machine movements. In case of any digital sensor failure, the entire machine goes into hold mode with the propellant bowl being stuck with it. This hinders the failure diagnosis and rectification activities seriously due to safety concerns. Hence, an attempt has been made in this paper for retrieving the bowl cleaning machine to its home position safely in case of digital sensor failure. Thereby, enabling the shifting of propellant bowl to the standby machine. An equivalent simulation network for the proposed algorithm is designed using ladder logic and is analyzed by Karnaugh Map and Boolean algebra. Sum of product expression is derived and is validated by acquiring the status of digital input module for the corresponding channels in response to sensor simulation using S7-315 2PN/DP PLC and WINCC SCADA 7.4. Proposed network performance is validated by plotting the process trends in case of sensor failure scenario.