This site provides information about process control, particularly the PID control algorithm, controller tuning, cascade control, ratio control, and other topics.
PID is the control algorithm most often used in industrial control. It is implemented in industrial single loop controllers, distributed control systems (DCS) and programmable logic controllers (PLC).
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Buy and download my eBook: The
PID Control Algorithm: How It Works, How To Tune It, and How to Use It. 2nd ed.
62pp |
 Most major credit cards accepted.Get more details, buy, and download |
| ControlSim The PID controller and process simulator based on MS Excel spread sheets. $45.00 | Most major credit cards accepted. Get more details, buy, and download |
Questions and answers
Periodically I publish a question and answer. The questions come from e-mail to john@jashaw.com, are posted on various forums such as control.com or the sci.engr.control news group, or the forum on www.jashaw.com. The answers are those I have provided either on the forum or by e-mail. Often the questions and answers are rewritten to make them more generally applicable. Several questions may be combined into one general question, therefore names will not.usually be used.
How is the controller action affected if the valve is Air to Close (Fail Open)? NEW!
Difference between series and parallel derivative and integral
Derivative on process rather than error
Proportional vs. Proportional-reset for level control.
Reset windup and the problems it can cause.
Best scan time for loops.
Velocity and Full Value forms of the PID algorithm.
Interactive and non-interactive integral and derivative.
Fail safe level switch connections.
What is the "standard" PID equation? Gain affects all terms?
What are the benefits of realistic 3-D graphics for operator interface?
Should derivative be used on temperature loops?
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Information about the PID algorithm:
Tutorial on the PID control loop and tuning (in 6 parts)
This tutorial describes the PID control algorithm, how it works, and how it is
tuned.
Brief
Explanation of the PID control algorithm
A brief version of the tutorial.
Suggested Code
for the PID Algorithm
Two suggestions about how to implement the PID algorithm in digital form.
Information about more complex strategies;
Override Control
When there is some other measurement that must be constrained, forcing the output of a
controller to follow another controller's output.
Cascade Control
A short explanation, with diagrams, of cascade control and the details of its
implementation.
Ratio Control
A short explanation, with diagrams, of ratio control and the details of its
implementation.
Control Views
News, articles, and comments from the world of process control.
Working for yourself
Information about consulting, contracting, and self employment.
Know someone interested in PID control? Click here to Email them a link to this site.
Dealing with Uncertainty in Process Design: Monte Carlo Simulation.
Information about apartments in Ballantyne, South Charlotte, NC Click Here!
Thousand Acre Swamp Hike Schedule
A schedule of the 2006 public hikes at Thousand Acre Swamp in Penfield, NY
Also of interest:
Control Engineering Information, my new site.
Process
Measurement and Control Forum for discussion of all aspects of process measurement and
control,
The sci.engr.control news group has discussions of interest to control engineers. Google
groups: sci.engr.control
Buy books on control topics. I have a list of
books I recommend for reference and for learning about control.
| ControlSim The PID controller and process simulator based on MS Excel spread sheets. $45.00 | Click here to get more details, buy, and download |
Buy and download my eBook: The
PID Control Algorithm: How It Works, How To Tune It, and How to Use It. 2nd ed.
62pp |
Most major credit cards accepted. Get more details, buy, and download |
