Programmable Logic Controller Block Monitoring System for Memory Attack Defense in Industrial Control Systems

Cyberattacks targeting industrial control systems(ICS)are becoming more sophisticated and advanced than in the past.A programmable logic controller(PLC),a core component of ICS,controls and monitors sensors and actuators in the field.However,PLC has memory attack threats such as program injection and manipulation,which has long been a major target for attackers,and it is important to detect these attacks for ICS security.To detect PLC memory attacks,a security system is required to acquire and monitor PLC memory directly.In addition,the performance impact of the security system on the PLC makes it difficult to apply to the ICS.To address these challenges,this paper proposes a system to detect PLC memory attacks by continuously acquiring and monitoring PLC memory.The proposed system detects PLC memory attacks by acquiring the program blocks and block information directly from the same layer as the PLC and then comparing them in bytes with previous data.Experiments with Siemens S7-300 and S7-400 PLC were conducted to evaluate the PLC memory detection performance and performance impact on PLC.The experimental results demonstrate that the proposed system detects all malicious organization block(OB)injection and data block(DB)manipulation,and the increment of PLC cycle time,the impact on PLC performance,was less than 1 ms.The proposed system detects PLC memory attacks with a simpler detection method than earlier studies.Furthermore,the proposed system can be applied to ICS with a small performance impact on PLC.

Synthesis of Nonlinear Control of Switching Topologies of Buck-Boost Converter Using Fuzzy Logic on Field Programmable Gate Array (FPGA)

An intelligent fuzzy logic inference pipeline for the control of a dc-dc buck-boost converter was designed and built using a semi-custom VLSI chip. The fuzzy linguistics describing the switching topologies of the converter was mapped into a look-up table that was synthesized into a set of Boolean equations. A VLSI chip–a field programmable gate array (FPGA) was used to implement the Boolean equations. Features include the size of RAM chip independent of number of rules in the knowledge base, on-chip fuzzification and defuzzification, faster response with speeds over giga fuzzy logic inferences per sec (FLIPS), and an inexpensive VLSI chip. The key application areas are: 1) on-chip integrated controllers;and 2) on-chip co-integration for entire system of sensors, circuits, controllers, and detectors for building complete instrument systems.

Real Time Control System for Metro Railways Using PLC & SCADA

This paper proposes to adopt SCADA and PLC technology for the improvement of the performance of real time signaling&train control systems in metro railways.The main concern of this paper is to minimize the failure in automated metro railways system operator and integrate the information coming from Operational Control Centre(OCC),traction SCADA system,traction power control,and power supply system.This work presents a simulated prototype of an automated metro train system operator that uses PLC and SCADA for the real time monitoring and control of the metro railway systems.Here,SCADA is used for the visualization of an automated process operation and then the whole opera-tion is regulated with the help of PLC.The PLC used in this process is OMRON(NX1P2-9024DT1)and OMRON’s Sysmac studio programming software is used for developing the ladder logic of PLC.The metro railways system has deployed infrastructure based on SCADA from the power supply system,and each station’s traction power control is connected to the OCC remotely which commands all of the stations and has the highest command priority.An alarm is triggered in the event of an emergency or system congestion.This proposed system overcomes the drawbacks of the current centralized automatic train control(CATC)system.This system provides prominent benefits like augmenting services which may enhance a network’s full load capacity and networkflexibility,which help in easy modification in the existing program at any time.

基于PLC反渗透海水淡化控制系统的设计与开发

针对反渗透海水淡化系统工艺复杂、运维繁琐、对操作人员专业技能要求高的特点,研发了一套反渗透海水淡化控制系统。详细研究整个工艺系统中预处理、反渗透等关键工艺环节的原理及自动控制过程。从系统的硬件设计和软件开发两个方面进行详细阐述。硬件设计方面,根据装置规模和控制需求完成控制系统设备选型。软件开发方面,完成控制器及人机交互界面多套软件的开发。该系统成功应用于高校反渗透海水淡化教学实践课。应用结果表明:该系统设计合理、操作界面简洁方便,在稳定安全运行的同时可实现教学培训、故障处理等目的。该系统在提高海水淡化操作人员专业技能的同时,也对高校创新其他专业的实操培训课程提供了借鉴和技术支撑。

基于ControlLogix的PLC冗余控制系统设计

从Rockwell Automation工业控制网络的架构以及组网方式出发,阐述了基于ControlLogix5550控制器的PLC冗余控制系统的实现过程。

基于5G多接入边缘计算的云化PLC系统架构设计与应用

随着工业控制系统对柔性化、扁平化的要求不断提升,以PLC为构建基础的传统工业控制网络在大规模接入、算力提升和部署灵活性方面均受到限制.针对这些问题,融合5G网络和边缘计算技术,设计了基于5G多接入边缘计算的云化PLC系统架构,阐述了该架构的运行机制和所涉及的关键技术;在此基础上,进行PLC系统的云化部署和调试,实现了工业现场、企业数据中心、5G网络和边缘网络的集成;最后,通过在某汽车制造公司产线改造过程中的应用,验证了所提架构的有效性.

基于PLC的气动搬运机械手自动控制系统设计

为提高气动搬运机械手在复杂工厂流水线中的运行效率,该文设计了一套基于PLC的气动搬运机械手自动控制系统。在分析通用气动机械手将物品在不同位点之间搬运的运动流程的基础上,设计了自动控制系统的硬件架构。其中包含了可编程逻辑控制器(PLC)、伺服电机、传感器和交互屏等器件,并根据气动搬运机械手的运动流程,设计了相应的软件控制程序及界面。仿真实验结果证明,所提出的气动搬运机械手自动控制系统可以稳定地完成实验预设的功能需求,自动化程度较高。

基于PLC的滤站自动控制系统设计

针对滤站的污水处理流程,设计基于可编程逻辑控制器(Programmable Logic Controller,PLC)的滤站自动控制系统,并详细阐述该系统的硬件设计、软件设计。通过应用自动控制系统,滤站能够自动完成污水处理流程,缩短人工时间,提高工作效率。

PLC技术在电气设备自动化控制中的应用

阐述PLC技术在电气设备自动化控制中的应用特点,包括可编程、灵活性、可靠性、实时性和可视化界面。探讨PLC技术在开关量控制、闭环控制、顺序控制中的控制应用。

基于PLC的自动测流机器人系统设计

针对当前河道测流存在的效率和自动化程度较低、测量模式单一等问题,提出了一套基于可编程逻辑控制器(PLC)的河道自动测流机器人系统设计与实现方案。该机器人系统由运动系统、采集系统、人机交互以及远程通信四大模块组成。首先,设计了自动测流机器人系统的硬件结构,实现了自动测流机器人在河流轨道上运动、铅鱼收放等功能。然后,开发了基于PLC的测控系统,设计了PLC梯形图和硬件连接方案,实现了自动测流机器人运动控制。最后,自动测流机器人系统通过RS-485通信协议将多传感器采集的数据传输到操控屏,结合4G远程技术,实现了采集数据和操作指令的远程传输。通过现场模拟的采集测试,该机器人系统可实现自动测流、远程操控、故障自检等功能,并提供多种测量模式,满足河道测流的使用需求。该系统的设计为开展智能化河流数据采集的研究奠定了基础。

Research on rapid development platform of PLC control system

In the field of industrial process control,a fast-development platform for programmable logic controller(PLC)systems is designed in order to solve two main problems of rapid development of PLC control system and programmability of controlling software.In the aspect of design,the platform is composed of hardware controlling and software monitoring and is taking industrial computer as the core.Under the Windows environment,the platform establishes the control instruction set,develops the configuration function and visual programming function of the monitoring software and it integrates PLC controller based on Visual Basic software.In order to achieve the function of data monitoring,it has realized the serial communication between computer and PLC by using RS-485 and RS-232 serial ports line communication.The platform designs the intelligent instruction scheduling strategy by studying the encoding and decoding rules of the communication instruction set.It proposes a method for rapidly developing control programs by adopting the expert control mode,which enables clients to develop and modify programs conveniently by importing instructions in a non-coded manner.After experimental testing,the platform is proved successful achieving both the rapid development of PLC control system and the rapid modification of monitoring software.

基于PLC的豆粕固态发酵温度控制系统设计与试验

为了在豆粕固态发酵过程中给微生物提供适宜的生长繁殖条件,达到良好的发酵效果,对温度变化复杂的发酵环境进行实时的温度监测和控制。采用PLC对发酵罐的温度进行PID闭环控制,设计以37℃为目标值的试验。结果表明,发酵的豆粕中多肽含量、ACE抑制活性在终点时分别达到4.45 g/kg,53.2%,分别比自然发酵状态下提高5.7%和9.92%,温度控制系统有效提高了豆粕发酵产物的质量。研究为面向生产的豆粕固态发酵提供理论基础。

基于PLC的仓库灯光指引系统

基于可编程逻辑控制器(Programmable Logic Controller,PLC)的仓库灯光指引系统,即利用灯光指引位置进行定位。该系统适用性广泛,不仅在仓储行业内使用,还可以应用在其他行业,为提高效率发挥重要作用。设计灯光指引系统可以实现客户端数据采集,客户端和下位机间的数据传输,以及下位机对LED灯进行驱动等功能。最后,系统利用不同灯号的不同颜色,表示不同功能的状态。

Synchro Controller of Radar on FPGA

This paper mainly represents the realization of synchro controller based on the programmable logic devices FPGA by request of HF ground wave radar synchro controller under the instance of making the best of the virtues of FPGA. This design introduces the data communication between PC and synchro controller by PC Bus, which can carry the synchronous signals parameters to RAM of synchro controller, then according to the theory that the result of comparing counter value with signals parameters is the needed wave, we produce all waves HF ground wave radar needs, moreover all waves are produced time-sharing in order to save resources.

PLC辅助下船舶柴油发电机转速控制研究

柴油发电机在运行过程中受到外部扰动时转速的波动幅度增大,影响发电机的输出稳定性和效率,因此,本文提出一种PLC(可编程逻辑控制器)辅助下船舶柴油发电机转速控制方法。根据柴油发电机的基本工作结构,对其各个部件的模型进行构建与分析。通过分析各部件模型得出的参数和特性,从静态与动态2个角度出发,选取船舶柴油发电机转速控制指标,包括静差率、超调量和动态降落。将上述指标与PLC程序逻辑结合,通过监测实时数据来判断当前状态,然后根据反馈信息调节控制参数,有效地控制柴油发电机的转速。实验结果表明,本文方法能够更加快速地调整柴油发电机的转速,并且受到外力扰动时能够迅速调整回归平稳运行状态,保证柴油发电机的长期平稳运转。

Multisim仿真技术在PLC教学中的应用

为打破PLC实验室建设的各项限制,提升PLC课程教学效果,拓宽PLC实验教学内容,提高学生的实践动手能力和创新能力,将Multisim仿真技术应用到PLC教学中。利用Multisim开发虚实结合的PLC实验教学平台,并在此基础上构建了虚实结合的创新型教学体系,探索了Multisim在PLC教学中的应用。教学平台的开发与实施得到了学生的好评,为PLC的实验教学开辟了一种新的路径。

Evaluation of Selected Control Programming Languages for Process Engineers by Means of Cognitive Effectiveness and Dimensions

Different programming languages can be used for discrete, abstract and process-oriented programming. Depending on the application, there exist additional requirements, which are not fulfilled by every programming language. Flexible programming and maintainability are especially important requirements for process engineers. In this paper, the programming languages Activity Diagram, State Chart Diagram and Sequential Function Chart are compared and evaluated with regard to these requirements. This evaluation is based on the principles of cognitive effectiveness and cognitive dimensions. The aim of this paper is to identify the programming language suited best for controlling sequential processes, e.g. thermomechanical or batch processes.

基于PLC控制的包装粮码垛系统设计

为了提高包装粮码垛的自动化程度及节约成本,笔者设计了一款基于PLC控制的包装粮码垛系统。该装置采用机械手与天轨系统相结合的方法,使用齿轮齿条进行传动,采用仿真分析与公式计算对天轨横梁进行强度校核;控制系统采用PLC与制造执行系统(manufacturing execution system,MES)控制相结合的方法,采用Socket通信协议,运用了模块化的编程原理。结果表明:该套系统可以实现全程无人化自动运行,验证了系统的可行性。该套系统在食品包装领域具有一定的实用性和推广性。