How many different basic elements exist in control logic?

• A. Six
• B. Four
• C. Five
• D. Seven

Answer: (A)

Control logic is built from six basic building blocks that cover sensing, decision-making, timing, counting, state retention, and action. Sensors provide the input signals from the environment. The decision logic evaluates these signals to determine if the current conditions meet the required criteria. Timers introduce delays or control time-based sequences. Counters track how many times a condition occurs or how many items pass, triggering actions after a set count. Memory holds the current state so the system can maintain behavior across cycles. Outputs or actuators carry out the chosen action to affect the physical process. Together these six elements—sensing, decision logic, timing, counting, memory, and actuation—form the core structure of control logic. Therefore, there are six basic elements.