Controllers, Controller Schemes and Modes, Final Control Element PART 1 of 2

Set Point

The predetermined desirable operational state of a process; a reference point for the controller.

Process Error

The deviation of the actual process variable from the set point; the controller's goal is to minimize this deviation.

Control Valves and Regulators

Components responsible for manipulating process conditions based on control signals, executing physical changes in the process.

Direct Acting

A configuration where an increase in the input signal results in a corresponding increase in output.

Reverse Acting

A configuration where an increase in the input signal leads to a decrease in output, often used in safety-critical systems.

Gain

The degree of output response relative to input change, typically expressed as a ratio.

Proportional Band

The range of input change that results in a full change in output, usually expressed as a percentage.

Split Range Control

A control system that uses multiple valves or actuators controlled by the same controller for complex process efficiency.