Exam Question
With reference to control system state what is meant by:
(a) Two step action (6)
(b) Proportional control; (5)
(c) Offset (5)
Class 4 (4th Engineer)
MEKG
📅 Oct 2025
Reference Answer
### (a) Two-Step Action (6 Marks)
Two-step action, also known as on/off or two-position control, is the simplest mode of automatic control. The final control element (e.g., a valve, heater, or pump) has only two possible states: fully ON or fully OFF.
**Principle of Operation:**
* The controller compares the measured Process Variable (PV) to a desired Setpoint (SP).
Two-step action, also known as on/off or two-position control, is the simplest mode of automatic control. The final control element (e.g., a valve, heater, or pump) has only two possible states: fully ON or fully OFF.
**Principle of Operation:**
* The controller compares the measured Process Variable (PV) to a desired Setpoint (SP).
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