Looks scary right! On a side note, if you are interested in a more in-depth look into PID and closed loop feedback systems I do highly recommend these two texts, Feedback Control of Dynamic Systems 7th Edition and Control Systems Engineering 7th Edition.īoth are excellent resources, however, one word of warning they do get pretty heavy into the theory behind closed loop feedback and control. The term PID stands for P roportional, I ntegral, D erivative and the complete mathematical algorithm can be broken down into these three constituent parts, namely, the P-term, the I-term and the D-term. Just like any control algorithm with any complexity, the mathematical foundations will prove paramount to our overall understanding.
To explain PID in its entirety we are going to have to dive a little bit deeper into some of the mathematics involved. Different types of processes, having different dynamic time-dependent behaviors require different levels of proportional, integral and derivative controller action to achieve stability and robust response. PID control is by far the most common feedback control algorithm used in industry today.
Before we can dive right into the implementation and configurations necessary to implement a ControlLogix PID controller, I think it will be prudent to review some key concepts regarding closed loop feedback, specifically what PID feedback control is, and what constraints or inherent issues that you are likely to encounter when implementing any real-world PID process.