Control Notes

If you design processes or control loops, you might have to come up with reasonable controller settings before you have the chance of doing any tuning. If you are faced with this situation, you could use the table of typical controller settings below to give you more appropriate starting values for a controller.

The table can also be used to validate tuning settings on problem control loops. Sometimes one setting is so far off that simple trial-and-error tuning seems to make no difference. If you compare your controller settings to those in this table, you might find the culprit setting.

Important:

Settings in this table are for information only. Process characteristics can vary widely from the “typical” process, requiring greatly different controller settings. You should always tune a controller according to the actual process dynamics (by doing step tests and applying the appropriate tuning rules) before anyone places it in automatic control mode.

The controller settings are for controllers with the noninteractive algorithm, using controller gain for proportional and minutes for integral and derivative. If your controller has a different algorithm or uses different engineering units, you have to do the appropriate conversions.

If you have any questions or suggestions about the settings, please contact me.

Stay tuned!
Jacques Smuts – Author of the book Process Control for Practitioners