PLCpõhiseid

PLCpõhiseid refers to control systems built around programmable logic controllers (PLCs) to automate machines, lines, or processes. In these configurations, the PLC acts as the central decision maker, coordinating inputs from sensors and status outputs to actuators and field devices.

Typical components include PLC hardware (CPU, power supply, I/O modules), sensors, actuators, HMI (human–machine interface) or SCADA software, and communication networks such as Ethernet, Modbus, Profibus, or Profinet. Programming follows IEC 61131-3 standards and commonly uses ladder logic, function blocks, structured text, instruction list, or sequential function charts.

Common applications span factory automation, packaging lines, automotive assembly, water and wastewater treatment, food processing, and building management systems. PLC-based solutions are valued for deterministic timing, robustness in industrial environments, and ease of modification without a full computer system overhaul.

Advantages include reliability, real-time performance, and modularity through add-on I/O or expansion blocks. Limitations include limited processing power compared to PC-based controls, potential vendor lock-in, and the need for careful software engineering to handle complex interactions. Integration with enterprise IT and cybersecurity considerations are ongoing concerns.

Development typically follows a lifecycle of specification, hardware selection, programming, simulation or testing, commissioning, and maintenance. Safety- and security-related features may drive the use of safety PLCs or layered architectures with separate safety routines and protective interlocks. Standards such as IEC 61131-3 and ISO 13849-1 guide programming practices and risk assessment.