Programmable Logic Controller Control Research Articles

StructuredFuzzer: Fuzzing Structured Text-Based Control Logic Applications

Rigorous testing methods are essential for ensuring the security and reliability of industrial controller software. Fuzzing, a technique that automatically discovers software bugs, has also proven effective in finding software vulnerabilities. Unsurprisingly, fuzzing has been applied to a wide range of platforms, including programmable logic controllers (PLCs). However, current approaches, such as coverage-guided evolutionary fuzzing implemented in the popular fuzzer American Fuzzy Lop Plus Plus (AFL++), are often inadequate for finding logical errors and bugs in PLC control logic applications. They primarily target generic programming languages like C/C++, Java, and Python, and do not consider the unique characteristics and behaviors of PLCs, which are often programmed using specialized programming languages like Structured Text (ST). Furthermore, these fuzzers are ill suited to deal with complex input structures encapsulated in ST, as they are not specifically designed to generate appropriate input sequences. This renders the application of traditional fuzzing techniques less efficient on these platforms. To address this issue, this paper presents a fuzzing framework designed explicitly for PLC software to discover logic bugs in applications written in ST specified by the IEC 61131-3 standard. The proposed framework incorporates a custom-tailored PLC runtime and a fuzzer designed for the purpose. We demonstrate its effectiveness by fuzzing a collection of ST programs that were crafted for evaluation purposes. We compare the performance against a popular fuzzer, namely, AFL++. The proposed fuzzing framework demonstrated its capabilities in our experiments, successfully detecting logic bugs in the tested PLC control logic applications written in ST. On average, it was at least 83 times faster than AFL++, and in certain cases, for example, it was more than 23,000 times faster.

Programmable logic controlled lithium-ion battery management system using passive balancing method

Advancements in electric vehicle technologies and the widespread adoption of electric vehicles have brought energy storage systems to the forefront. However, efficient and secure utilization of energy storage systems requires Battery Management Systems (BMS).BMSs are typically designed with power electronics, electronic cards, integrated circuits, and auxiliary hardware components. Nevertheless, BMSs designed with such microcontrollers can only control a limited number of battery cells and constrained current values. Furthermore, employing a separate controller for each battery pack exacerbates these issues.In this study, a Programmable Logic Controller (PLC) - based BMS proposal for lithium-ion batteries has been presented, aiming to address the challenges in existing BMSs. The developed system is a passive balancing BMS comprised of controller PLC modules and auxiliary hardware. The Ladder Diagram (LD) programming language was employed for programming the PLC.In the conducted research, the voltage levels of the cells comprising the battery pack were monitored, and a passive balancing method was employed to equalize the cell voltages. Passive balancing has been applied to cells with voltage values of 2.70 V, 2.40 V, and 2.80 V using the minimum reference voltage cell balancing method to equalize the voltage levels. The output voltage has been balanced according to the maximum reference charge voltage set at 6 V through the maximum reference charge voltage balancing method. Additionally, a cooling circuit was integrated into the system to safeguard the Battery Management System (BMS) against thermal hazards. The developed PLC controller and algorithm can effectively control multiple battery packs with a single controller and operate at higher current values. This advantage allows the PLC-controlled BMS to have a broader control capacity. The presented test results indicate the successful performance of the PLC-based BMS.

Development of PLC-Based Hardware Test-Bench Prototype for Solar-Wind-Battery-Based Microgrid System’s Control Algorithm Validation

Programmable Logic Controllers (PLCs) are gaining traction in microgrid operation due to their real-time deployment, reliable and robust operation, and fast response, even in harsh environments. Recognizing the critical need for robust and reconfigurable microgrid control and operation, this research proposes a hardware test-bench prototype using the Reconfigurable Allen-Bradley—Micro820/2080-LC20-20QBB PLC to demonstrate control algorithms aiming for efficient control, energy management, and resilient microgrid automation. The design and construction of a prototype controller test bench, along with the PLC configuration, wiring diagrams, and control logic, constitute the significant contributions of this research. The proposed controller test bench’s performance is evaluated through similar condition simulations in the presence of disturbances induced by the reduced contributions of renewable energy sources, such as solar and wind. The results illustrate the effectiveness of the developed control algorithm implemented in the proposed controller, ensuring the stable operation of the microgrid. Consequently, this work advances the simulation-based validation of microgrid control algorithms and provides insights into the practical application of a PLC-based hardware test bench under various environmental conditions.

Dizajn i razvoj troškovno-efikasne robotske ruke sa robotskim kontrolerom baziranim na PLC-u

To develop a cost-efficient robot arm for a typical pick and place application that can applied in industry, this paper deployed a programmable logic controller (PLC) to control the rotation motion of the robot joints. The main tasks of the PLC controller are to calculate the kinematics, create high-speed pulse outputs for stepper motors, and implement sequence operations for a certain application. Functions are written into subprogram segments. When needed, the main program only turns on the corresponding flag for executing the subprogram. Using the pre-written subprograms, a logical sequence to implement the Pick and Place application is easily implemented and described in this paper. The PLC program is developed to control a SCARA robot with three rotation joins. Stepper motors drive the robot joints. The Delta DVPSV2 PLC is utilized to design the robot controller. This PLC series has four high-speed pulse output pins, which is suitable for this project. Synchronous motion of stepper motors is easily performed using high-speed pulse output commands built into the PLC program. Experimental results of robot arm control have demonstrated the efficiency and accuracy of the developed program. The robot arm's forward and inverse kinematics problems are verified using the simulator on the software. The robot's joints move synchronously as required to perform pick-and-place applications.

Design of Programmable Logic Controller (PLC) on Smart Fertilizer Distribution System

The control system in agriculture is an important study to regulate the application of fertilizers to plants. The control system can use PLC control system which has good system robustness and easy program language. The purpose of this research is to design a simulated fertilizer irrigation system based on a programmable logic controller (PLC) system. The PLC program used is CX-program and the simulator circuit uses Fluidsim simulator. The system components used are the main reservoir, pump, solenoid valve, valve, level sensor, and light indicator. The system is organized by dividing inputs and outputs that are directly integrated into the PLC system. The components are arranged using fluidsim and the PLC control system using CX-Programmer using ladder logic language. The control system integration and system circuitry are connected using KeepServerEX. The output of this system is a successful operation function and a digital system response to the time of the system. From the results of the system response provides a fairly good timeliness so that this irrigation system can be considered in the implementation of fertilizer delivery system

Design and simulation of PLC and HMI-Based control and monitoring system of compressed air application in a pineapple cannery industry

Energy Conservation or ENERCON is the main concern of every industry today. With the advent of new technology installed in the process line, the need to address the conservation of applied energy such as steam, water, electricity, and compressed air are still the core to run an industrial plant. The use of compressed air as a blower is widely used now a day for several benefit compared to running the blowing system with the motor. The system presented in this study is used to automatically switch off the compressed air that serves as a can top blower before printing whenever there are no can detected in the conveyors in a pineapple cannery industry. The cutting off of the compressed air used will result in significant saving in the plant-wide drive on conserving energy. The hardware composition, control system design, software application and simulation of the Programmable Logic Controller (PLC) and Human Machine Interface (HMI) - based monitoring and control system of compressed air are present in this work. The system’s main components are PLC, HMI, Inductive sensors and Directional valves. This paper focuses on the application for a pineapple manufacturing plant but not limited to the compressed air application but for all the industrial utilities mention above.

Automation of Load Electricity Operating System Using PLC (Programmable Logic Controller)

Jakabaring PLTS on-grid with a capacity of 2 MW operates from 6:00 am to 5:00 pm. At 5:00 pm the PLTS connection to the load will be disconnected and replaced with PLN. If the PLN is off due to damage or during maintenance, a generator that is operated manually will be used. Problems in the process of combining energy sources from Solar Panels to PLN require a power target of up to 10 Kva where if the power is fulfilled then the energy source from Photovoltaic (PV) will be connected to PLN and vice versa. Errors and speed in operation can be minimized by means of automation of the system operating the power supply to the load by using a PLC (Programmable Logic Controller). Optimization as a step to optimize the electricity supply in the PLTS area makes it the first source of power generation that is connected to the load, the second order is PLN if the PLTS has no power output or there is a problem and the third order is generators if PLN and PLTS have no power output. For this reason, a tool is needed that functions to move the power source alternately using a PLC (Programmable Logic Controller) as an ATS (Automatic Transfer Switch) process controller, where the tool will work automatically changing the power source if there is a disturbance that causes it to be unable to supply electricity to the user's load and also as a priority regulator of solar power sources as the main source of electricity to the load. When transferring loads from one source to another with 3 different power sources, it is faster and more effective to use an ATS (Automatic Transfer Switch) with a PLC controller compared to Manual or COS (Change Over Switch).

Development of integrated semi-active adaptive vibration control system for bridges subjected to traffic loads

Nowadays, the fluid viscous damper is the most conventional energy dissipation system implemented in bridge structures to control the vibrations due to traffic loads. However, to effectively protect the bridge against frequent and severer vibrations, it is required to adapt the function of the damper according to the variable traffic loads. In this research, an Integrated Semi-Active Adaptive Vibration Control System is developed for the bridge structures. This control system consists of a Semi-Active Bypass Fluid Damper (SABFD), a programmable logic controller (PLC), pressure transducers, and displacement sensors. Semi-Active Bypass Fluid Damper is a hydraulic cylinder with a pair of external bypass pipes with motorized electric flow control valves which are installed in the middle of pipes to control the flow rate of the fluid. A programmable logic controller (PLC) is implemented to manage the operation of motorized valves according to the movement of the bridge.Therefore, the integrated control system is able to function as a real-time controller during its operation. To develop the control system, the performance of the SABFD device has been assessed through analytical model of the various control valve positions. Then, according to the structure response, a fuzzy control algorithm has been adapted in the PLC controller.Afterward, the prototypes of the SABFD and the PLC controller have been fabricated and a series of cyclic load tests have been conducted by using a dynamic actuator. The outcomes of the numerical analysis and results of the experimental tests revealed that the developed device is capable of generating a wide range of forces during device operation. The developed fuzzy control algorithm is then implemented to the finite element model of the bridge equipped with SABFD, and the results proved that the real-time control system effectively limits the bridge displacements according to the pre-defined fuzzy control rules.

Penyusunan Jobsheet Kendali Motor Servo Berbasis Human Machine Interface

One of the Practice courses for the D3 Electrical Engineering study program at the Electrical Engineering Department is Electrical Machine Control Practice. One of the materials given in this Electric Machine Control Practice is servo motor control. Along with technological developments, in the electrical energy conversion laboratory as a place for Electrical Machine Control Practice, a servo motor control training kit is available using a Programmable Logic Controller (PLC) and Human Machine Interface (HMI). Based on the observations made, the PLC and HMI-based servo motor control training kit does not yet have a manual or jobsheet as a guide for students and lecturers in carrying out practical activities. Therefore, in this study it is proposed to make a servo motor control jobsheet based on PLC and HMI using the Siemen S7 1200 PLC training kit with a Sinamic V90 servo motor driver and HMI TP 700 Comfort. The feasibility of the jobsheet is assessed from the validity, practicality and effectiveness tests with research procedures following the 4D development research method, which consists of the stages of define, design, development and dissemination stages. Based on the results of the tests carried out, the validity test results are obtained in the very valid category, the practicality test results are in the very practical category and the effectiveness test results are in the effective category. So that the jobsheet can be considered feasible to be used as a guide in implementing PLC and HMI-based servo motor control practices.

Rancang Bangun Pengupas Kelapa Muda Berbasis Progam Logic Controller and Human Marchine Interface

In general, the design of the young coconut peeler machine is to use an induction motor that still uses a manual system to turn the tool on and off, so it is not efficient in the production process of peeling young coconut. The speed of the induction motor can be adjusted by changing the frequency, therefore a Variable Speed ​​Drive (VSD) is needed which aims to regulate the rotational speed of the induction motor. As the controller of the Variable Speed ​​Drive (VSD), the compiler uses a Programmable Logic Controller (PLC). From the description of the background above, a young coconut peeler based on PLC and HMI was designed. This system uses PLC control as a control for variations in the rotation speed of the motor, so that the rotation of the induction motor can be controlled as needed, in this tool an HMI system is applied which functions as an interface display from the operator to the peeler. In this study using 4 stages, namely (1) a needs survey, (2) designing (3) prototypes, (4) testing prototypes. In the trial results, the simulation of the coconut peeler design went well by using low, medium, high speed variations using the human marchine interface as the display of the variable speed button, while the PLC as the control machine.)

DESIGN OF PLC BASED TEMPERATURE CONTROL SYSTEM FOR FOOD STABILITY TEST CHAMBER

A stability test chamber simulates specific environmental conditions and tests a product or material in the manufacturing stage. The tested product or material is then analyzed about its shelf-life estimation related to the state and durability of the product for a certain period. The main parameter that must control accurately is temperature. Programmable Logic Controller (PLC) as an industrial computer control system has been widely used. In this paper, the temperature control system was designed based on PLC and supervisory control and data acquisition (SCADA). The PLC and SCADA would indirectly control the heater. The PLC was feeded from the temperature sensor for real-time temperature inside the test chamber. Received temperature value, compared to the temperature set point. The validation and verification of controlled temperature inside the chamber were also investigated. The system was designed on a miniaturized chamber using commercial PLC and SCADA, Stepper motor, slide regulator, heater, and the temperature sensor PT100. The temperature test point for validation and verification was performed at 35 °C, 45 °C, and 55 °C. The result showed that The PT100 successfully had an excellent response to the temperature test point. The correction value for temperature is as high as 0.6 °C with a deviation of 1 %.

Defeat Magic with Magic: A Novel Ransomware Attack Method to Dynamically Generate Malicious Payloads Based on PLC Control Logic

The Industrial Control System (ICS) is a public facility that provides services to lots of users; thus, its security has always been a critical factor in measuring its availability. Recently, a new type of attack on ICS has occurred frequently, which realizes the extortion of users by invading the information domain and destroying the physical domain. However, due to the diversity and unavailability of an ICS control logic, the targets of such attacks are usually limited to PCs and servers, leaving more disruptive attack methods unexplored. To contribute more possible attack methods to strengthen the immunity of ICS, in this paper, we propose a novel ransomware attack method named Industrial Control System Automatic Ransomware Constructor (ICS-ARC). Compared to existing ICS ransomware, ICS-ARC can automatically generate an International Electrotechnical Commission (IEC) compliant payload to compromise the Programmable Logic Controller (PLC) without a pre-known control logic, dramatically reducing adversary requirements and leaving room for error. To evaluate the attack capability of ICS-ARC, we built a tap water treatment system as the simulation experiment target for verification. The experimental results determine that ICS-ARC can automatically generate malicious code without the control logic and complete the attack against target PLCs. In addition, to assist the related research on future attacks and defenses, we present the statistical results and corresponding analysis of PLC based on Shodan.

Modeling and simulation of electro-hydraulic telescopic elevator system controlled by programmable logic controller

Traditional hydraulic <span>cylinders are widely used in industry as load lifting tools. There is difficulty in employing these cylinders in narrow installation space like building elevators as well as they require a long working stroke, so solving this problem requires using the telescopic hydraulic cylinder instead. This cylinder is a unique hydraulic cylinder design that uses a sequence of decreasing diameters to create a long operating stroke in a compact-retracted form. In this work, the Auto Station software is used to build a telescopic hydraulic cylinder model that includes hydraulic elements such as double-acting hydraulic telescopic cylinders, pump, valves, pipeline, and filter, as well as electrical parts such as programmable logic controller (PLC), push-bottoms, and position sensors. The proposed model is operated by a PLC controller and has three floors with an overall height of around 300 cm for lifting a 100 kg payload. The accuracy and validity of this model in lifting big weights were demonstrated by the analytical findings of characteristic curves for cylinder position and velocity. This model can be used a basic reference to analyze and construct hydraulic cylinders with any number of stages. The findings of simulations reveal that a quick change in pressure due to phase change causes multi-phase vibration.</span>

Design and Implementation of PLC based Smart Coffee Maker

Automation is preferred in every production and service field to reduce human intervention to achieve high efficiency, reliability and less human effort. In this paper the design of a smart coffee maker is implemented using a Programmable Logic Controller (PLC). The proposed coffee machine includes eight different modes that offer hot drinks ranging from black coffee to white tea depending on the user’s input. Because of its durability and ease of installation and maintenance, the proposed Smart Coffee Maker system includes a PLC controller. Furthermore, the PLC monitors the input on a regular basis, and the actuators utilized in the project, such as the conveyor belt, various valves, and the lamp, are controlled based on the input and custom program downloaded in the PLC to achieve the automation of the coffee making process. Toggle switches are used to select the appropriate mode, while limit switches are used to assure the operation sequence by functioning as a control signal/input to turn the conveyor belt motor ON/OFF. The smart coffee maker technology has been tested in the laboratory and has shown to be effective.

Control System Upgradation with Linear Actuator in Coil Unloading Machine

Abstract: In this paper, we are going to see about the project is to unload the coil for the dispatching process from metal plate to place in thermo coal with the help of linear actuator. The process of coil unloading is automated with the help of HMI, sensors, motors and linear actuator. This process is carried out through ladder logic methodology. The linear actuator application machine process is the machine based on the PLC (PROGRAMMABLE LOGIC CONTROLLER) controller. Earlier PLC controllers are huge programmed size, spare parts are rare, inbuilt programming that could not change as per the requirements and the absolute models which is difficult to learn. The cam shaft mechanism takes over time to assemble the coil position. And also coils pick up and drop step by step process is difficult.To overcome this problem used the advanced PLC controllers model SIEMENS-S7 1200 instead of earlier telemechanic PLC controller because in this SIEMENS-S7 1200 model PLC the HMI is used to display the coil positions.

Design Robot Hand Pneumatic System Simulation Using PLC Control for Mechatronics Learning Applications

The Pneumatic System is a power transfer system utilizing compressed air as an intermediate medium. In conventional operation it is operated fully pneumatically or in combination with electricity (electropneumatic). In recent years it can be combined and controlled with a programmable logic controller (PLC). The operation of the pneumatic system with the PLC control system is carried out by desaign a program with a program language, one of which is the Ladder Diagram accompanied by I/O addressing, then the result design program must be transferred to the PLC as the controller of the pneumatic system in this case the controller. robot hand.
 This study aims to obtain a pneumatic robot hand circuit and a series of ladder diagram programs to control the PLC system in the robot's hand. The results of this research can be used as a reference in designing a pneumatic system with PLC control in the future.

AB PLC Based Intelligent Traffic-Congestion Control System Using Sensor

PLC or Programmable logic controller is used to control a mechatronics system using specific functions. Basic PLC functions such as timing, sequencing, controlling and relaying are to be implemented. The basic programming logic and ladder programming is to be studied and implemented. The intelligent or “Smart Traffic Control” is one which would be able to calculate the vehicle density in a lane at a 4-way crossing and then decide the priority automatically using a program. In practical situations sensors are used to detect presence of vehicles in a lane and calculate the density and sends an interrupt signal to the control unit. In PLC the status of the sensors are checked and certain logical operations are performed to decide which lane is to be serviced first. Under low density condition it would operate sequentially. Ladder diagram is to be developed for the implementation of the same in PLC. Key Words: Programmable Logic Controller (PLC), NO (Normally Open), NC (Normally Closed), R (Red), Y (Yellow), G (Green),

Memory forensic analysis of a programmable logic controller in industrial control systems

In industrial control systems (ICS), programmable logic controllers (PLCs) are used to automate physical processes such as nuclear plants and power grid stations, and are often subject to cyber attacks. As in conventional IT domain, the memory analysis of the PLCs can help answer important forensic questions about the attack, such as the presence of malicious firmware, injection of modified control logic (the program running on the PLC), and manipulation of I/O devices (e.g., sensors and actuators). Unlike conventional IT domain, PLCs have heterogeneous hardware architecture, proprietary firmware and control software, making it challenging to employ a unified framework for their memory forensics. For merely extracting artifacts of forensic importance, reverse-engineering the firmware is a tedious task, and the effort needs to be repeated for every PLC model. As a community, a step-wise approach to tackle this challenge is to analyze the memory of specific PLCs, and subsequently find a generic framework applicable to all PLCs. Our work is a step forward in this direction. By following a methodology that focuses on the functional layer of PLCs instead of reverse engineering the firmware, we analyze the digital forensic artifacts available in a common PLC, Allen-Bradley ControlLogix 1756-L61. Before diving into the memory dump, we analyze the PLC control software to create a list of important artifacts that are sure to exist in the PLC memory dump. The approach employs a setup where PLC control software RSLogix-5000 is connected to the PLC, and the memory dump can be obtained as and when needed. We create test cases that sequentially highlight each category of artifacts, followed by an examination of the resultant impact on memory. After attaining the listed artifacts, we employ conventional string and known data searches to extract interesting information present in this PLC's memory. The memory analysis profile, presented as a Python library and shared with the community, can help a forensic investigator to readily extract forensic artifacts from the same model's controller. The adopted approach may help researchers in creating memory profile of other PLCs, and ultimately formulating a generic PLC memory analysis framework.

Engineering Method and Tool for the Complete Virtual Commissioning of Robotic Cells

Intelligent robotic manufacturing cells must adapt to ever-varying operating conditions, developing autonomously optimal manufacturing strategies to achieve the best quality and overall productivity. Intelligent and cognitive behaviors are realized by using distributed controllers, in which complex control logics must interact and process a wide variety of input/output signals. In particular, programmable logic controllers (PLCs) and robot controllers must be coordinated and integrated. Then, there is the need to simulate the robotic cells’ behavior for performance verification and optimization by evaluating the effects of both PLC and robot control codes. In this context, this work proposes a method, and its implementation into an integrated tool, to exploit the potential of ABB RobotStudio software as a virtual prototyping platform for robotic cells, in which real robots control codes are executed on a virtual controller and integrated with Beckhoff PLC environment. For this purpose, a PLC Smart Component was conceived as an extension of RobotStudio functionalities to exchange signals with a TwinCAT instance. The new module allows the virtual commissioning of a complete robotic cell to be performed, assessing the control logics effects on the overall productivity. The solution is demonstrated on a robotic assembly cell, showing its feasibility and effectiveness in optimizing the final performance.

Energy-Saving in Air Conditioners Using PLC Control and the SCADA Monitoring System

The promotion of energy-saving air conditioners (ACs) continues to increase. Therefore, this research proposes the implementation of automatic control and monitoring for AC fan evaporator and compressor speeds using a programmable logic controller (PLC) along with supervisory control and data acquisition (SCADA). The proposed system uses a room-temperature sensor, connected to the PLC and programmed with a ladder diagram. It is connected to a SCADA installed computer for monitoring and data logging. The testing involves three methods: conventional, manual, and automatic PLC-based. Over a four-week period, the conventional method consumed 193.6 kW⋅h, 198.7 kW⋅h, and 206.6 kW⋅h in energy, while the manual method consumed 160.5 kW⋅h, 160.1 kW⋅h, and 161.9 kW⋅h, and the automatic method 150.8 kW⋅h, 152.6 kW⋅h, and 154.8 kW⋅h using the trapezoidal composite rule, Simpson's composite rule, and ordinary methods, respectively. The main research contribution is the provision of an energy-saving system for air conditioners over a long duration using PLC. The PLC-based automatic-to-manual energy savings equate to 6.0%, 5.8%, and 4.4%; whereas 22.0%, 24.0%, and 25.0% for the PLC-based automatic-to-conventional method. Therefore, the PLC-based automatic control is deemed appropriate for electrical energy-saving.