OPENPLC Sequential Control

This project demonstrates the design and implementation of a PLC-controlled timed light system, showcasing core industrial automation principles. The system is initiated through a start/stop mechanism, with the start button activating the sys_start signal to begin operations. A timer (TON0) counts 5-second intervals, triggering a counter (CTU0) that increments through states (0–3). At each state, an equality block (EQ) compares the counter value (state_led) with preset values to sequentially activate LEDs: green for state 0, yellow for state 1, and red for state 2. The system resets automatically after state 3 to repeat the process. Robust error handling ensures that any invalid counter state or system malfunction triggers an error signal (error), halts the system, and activates a flashing red LED (flash_red_led) to indicate the issue. This project highlights precision in ladder logic programming, state-based control design, and practical error management in industrial systems.