Industrial Control Systems (ICS) are frequently used in manufacturing and critical infrastructures like water treatment, chemical plants, and transportation schemes. Citizens tend to take modern-day conveniences such as trains, planes or tap water for granted without considering the critical systems involved for their operations. Interrupting these industries could lead to disastrous consequences, leading to financial losses or even costing human lives. For that reason, researchers have been actively investigating the threats targeting ICS. In this paper, the authors propose a mechanism of attack detection and mitigation for attacks focusing on the input memory of Programming Logic Controllers (PLCs). To help investigate this concept, a testbed that models a clean water supply system was built using components and technologies currently used in the industry. The mechanism supporting attack detection and response for the input memory is implemented within the PLC itself as part of its programming. The mechanism of response involves three different techniques: optimised datablocks, switching between control strategies and obtaining the sensor readings directly from its analogue channel. The results demonstrate the feasibility of the proposed approach along with the effectiveness of each response mechanism.

工业控制系统（ICS）经常用于制造和关键基础设施，例如水处理，化工厂和运输计划。公民倾向于将现代便利设施（例如火车，飞机或自来水）视为理所当然，而无需考虑其运营所涉及的关键系统。中断这些行业可能导致灾难性后果，导致财务损失，甚至造成生命损失。因此，研究人员一直在积极研究针对ICS的威胁。在本文中，作者针对编程逻辑控制器（PLC）的输入存储器提出了一种攻击检测和缓解攻击的机制。为了帮助研究这个概念，使用当前行业中使用的组件和技术构建了一个模拟清洁供水系统的测试平台。支持对输入存储器进行攻击检测和响应的机制是在PLC本身内部实现的，这是其编程的一部分。响应机制涉及三种不同的技术：优化的数据块，在控制策略之间切换以及直接从其模拟通道获取传感器读数。结果证明了该方法的可行性以及每种响应机制的有效性。在控制策略之间切换，并直接从其模拟通道获取传感器读数。结果证明了该方法的可行性以及每种响应机制的有效性。在控制策略之间切换，并直接从其模拟通道获取传感器读数。结果证明了该方法的可行性以及每种响应机制的有效性。