PLC (Programmable Logic Controller) is a digital control device used in industrial automation systems to manage machinery and production processes. It reads input data from sensors, processes it based on pre-programmed logic, and sends control signals to actuators. Thanks to its flexibility, durability, and programmability, it is widely used across various industries.

PID (Oransal–İntegral–Türevsel) kontrol ise; sıcaklık, basınç, hız gibi fiziksel büyüklükleri sabit bir değerde tutmak için kullanılan matematiksel bir geri besleme algoritmasıdır. PID kontrol, sistemin istenen hedef değere ulaşmasını ve bu değerde kararlı kalmasını sağlar.

These systems are often used together to provide automated and precise control over industrial processes. For example, in maintaining furnace temperature, motor speed regulation, or controlling pressure in a tank, a PLC runs a PID algorithm to stabilize the process.

Security Perspective

PLC and PID systems are critical components of industrial plants and security vulnerabilities can lead to serious consequences such as production stoppage, equipment failure, loss of control and human safety risk. In particular, network-based threats can cause manipulation of systems with unauthorised access and process sabotage via SCADA. As in the case of Stuxnet, these systems are important targets for cyber attackers.

Recommended Security Measures

• UTM (Unified Threat Management) Appliances: Deploy devices that combine multiple functions like intrusion detection, malware blocking, and content filtering in one hardware unit.
• UPS for Power Continuity: Protect critical controllers with uninterruptible power supplies (UPS) to avoid outages or electrical surges.
• Industrial Firewall Devices: Use hardware-based firewalls specifically designed for PLC networks to block unauthorized external data traffic.
• Environmental Surveillance Systems: Install cameras and motion detectors in PLC environments to monitor unauthorized physical access.
• Managed Switches for Data Isolation: Use VLAN-capable managed switches to physically separate the management network from the control network.