Implementation of PID control loops with S7 1200

In closed-loop control systems, the output value of the control loop always changes according to the set value (desired value for output) and the current value of the process (current state measured by the transducer). In other words, in such a system, the current value of the process is sampled at any time and compared with the set value, and the existing error value is calculated and an output value is sent to the output to compensate for the system error.

Various methods can be used to continuously control the output.
Proportional controller:
In this controller, the output is a coefficient of system error. Proportional controllers are built to solve the problem of frequent disconnections and connections in dual position controllers. By using proportional controllers and gain adjustment, more precision and sensitivity can be created in controlling a process.
Integral controllers:
The output of this controller is its input error integral. An integral controller is a memory controller, meaning that its output is affected by system errors in the past at all times.
Derivative controller:
The derivative controller is only sensitive to error changes and not to its magnitude. In other words, if the error is a fixed value and changes, it will not react to it. For this reason, derivation alone is not used. The derivation operation is suitable for delayed processes. Because error changes are usually a prelude to increasing them, the derivative controller is therefore prepared to correct future errors. That is, the controller has a forward-looking vision.
Proportional-integral controller:
The output of this controller is the sum of proportional and integral operations. In fact, these controllers have proportional and integral controller properties. PI controllers are used in systems where stabilizing the process value at the set point is more important than responding quickly to disturbances.
Proportional controller - derivative:
The output of this controller is the sum of proportional and derivative operations. In fact, these controllers have proportional and derivative controller properties. PD controllers are used in systems where the speed of response to disturbances is considered more than the permanent error correction.
PID controller:
This controller performs proportional, integral and derivative operations on the error signal. The PID controller is used to hold the system output constant at the set point and respond quickly to external disturbances.
Taken from the book of practical training PLC S7 1200 & PROFINET written by Mehdi Tavana Shirvan and Navid Entezari