Introduction to PID tuning with Ziegler-Nichols method (rule based variation) In this section, we’ll tune a PID with the Ziegler-Nichols Method. This will be a rule based variation. Previously, we discussed a trial and error based method. Recall that we increased Kc until the loop was unstable. At this point, Read More »
Introduction to PID Feed Forward PID Feed Forward allows you to immediately compensate for a change before Proportional, and Integral have a chance to act. It does this by BIASing the control variable. For example, consider a tank where we need to maintain a constant level. As soon as we Read More »
Introduction to Cascading PIDE (Enhanced) In this section we’ll discuss Cascading PIDE (Enhanced). We’ll set this up using the simulator. We’ll need two simulation units with a 1000uF capacitor across the PV of the flow simulator. Be sure to wire the PV of the flow simulator to the CV of Read More »
Introduction to Tuning the Simulator with an Enhanced PID (PIDE) Instruction There are a few things to keep in mind when tuning the simulator with the Enhanced PID (PIDE) Instruction. First of all, the PIDE uses Function blocks. You will need to make sure you have activated the Function Block Read More »
Introduction to Setting up the PIDE Instruction In this section, we’ll be Setting up the PIDE Instruction for use with our simulator. We’ll simulate a flow control process. To begin with, we’ll leave the simulator settings at default. Be sure to wire the CV from the simulator to an analog Read More »
Introduction to Cascading PID with ControlLogix Cascading PID is when one controller writes to the setpoint of another controller. The controller writing the setpoint is the master controller. Likewise, the PID instruction the master writes to is called the slave controller. Keep in mind that we’ve already set up the Read More »
Intruduction to Tuning a Simulator with the PID Instruction (using ControlLogix) In the previous section, we set up the PID instruction in ladder logic. We created a Task, a Program, and a Routine. Not only did we set up the configuration, but also the scaling. At this point, we are Read More »
Introduction to Ladder Logic for the PID Simulator (ControlLogix Processor) After you set up your main variables, we can configure Ladder Logic for the PID Simulator. I would recommend setting up a periodic task. We can place our PID logic in this task. This will guarantee the execution time of Read More »
Introduction to Setting up the PID Simulator When setting up the PID simulator, we will need to make a few connections. Also, we need to test the values to get our raw low and raw high. We will use these values for scaling. To build your own simulator, check out Read More »
Introduction to PID Terminology PID Terminology is essential to understanding how PID works. For this reason, we’ll go through various terms you will see when reading about PID. In short, PID itself stands for Proportional, Integral, and Derivative. Basically, the purpose of PID is to hold analog values at a Read More »
