Tag Archives: pid loop

Click PLC PID Instruction and Autotuning using Factory IO

A PID (Proportional, Integral, and Derivative) control is possible with the Click PLC. The Click Programming Software version 2.50 now includes PID. This features 8 full-featured control loops with an easy graphical user interface (GUI). PID will run on all of the Ethernet-enabled Click PLCs.
We will be using this PID along with a Factory IO scene to demonstrate PID control and Autotuning using our Click PLC.

Here are some references on PID control:
PID without a Ph.D. By Tim Wescott
Understanding PID in 4 minutes
PID Control – A brief introduction
PID Controllers Explained
Who Else Wants to Learn about On-Off and PID Control?
Our Factory IO scene will be controlling the level of water in a tank. PID will be used to maintain the level based on a dial pot knob on the control panel. Let’s get started! Keep on Reading!

Productivity 1000 Series PLC PID Ramp Soak Instruction

PID Ramp Soak Instruction
The purpose of a ramp soak instruction is to make gradual, controlled changes in temperature (Ramp), followed by a temperature hold (Soak) period.
We will be using our Proportional-Integral-Derivative PID Instruction that we looked at last time to apply the ramp/soak instruction.

Using the immersion heater in a cup of water to keep the temperature at a constant value, we will be adjusting the profile of the temperature as we increase the set point (Ramp) and hold that set point for a predetermined time. (Soak)

We will be modifying our existing program from our PID loop instruction. Let’s get started. Continue Reading!

Productivity 1000 Series PLC PID Instruction

PID Loop (PID) Instruction (Auto Tuning)
A Proportional-Integral-Derivative algorithm is a generic Control Loop feedback formula widely used in industrial control systems. A PID algorithm attempts to correct the Error between a measured process variable and the desired setpoint by calculating and then outputting a corrective action that can adjust the process accordingly and rapidly, to keep the Error to a minimum.

The following links will explain the PID instruction.
https://www.csimn.com/CSI_pages/PIDforDummies.html
http://www.ni.com/white-paper/3782/en/
https://en.wikipedia.org/wiki/PID_controller
We will be using an immersion heater in a cup of water to keep the temperature at a constant value. Using the Productivity Suite software we will perform an autotune on our PID instruction.

Our immersion heater will be controlled through a relay using time proportional control from our PID output. Let’s get started. Continue Reading!