**PID - Proportional Integral Derivative** Controller

The PID function uses system feedback to continuously control a dynamic process.

The purpose of PID control is to keep a process running as close as possible to a desired set point.

PID Means - Proportional + Integral + Derivative Control

CV = CV § + CV (I) + CV (D)

**Proportional Control**

Proportional Band - A band around SP is defined in percents of PV range.

Proportional error is 100% on the border of PB.

Proportional error is 0% at SP.

P-Control output CV§ value that is in - Direct linear proportion to the size of error value.

Advantages of Proportional Control-

Simple

Easy to implement

Disadvantages of Proportional Control-

Never reach setpoint.

**Integral Control**

Compensate for the proportional control shortcomings.

The integral time set is the ideal amount of time for the process value to reach setpoint.

**Derivative Action**

Derivative Action responds to the rate and direction of change in the error.