Resources -> PID Controllers:

Is there an Industry Standard for PID Controllers?

One day, a plant engineer, replaced his ageing PID controllers. Even though he used all the same settings on the new controllers, the retrofitted loops went dramatically unstable when placed in Auto mode.

He tried to tune these PID controllers using exactly the same technique with which he had tuned the old ones. The loops seemed to get more unstable.

This all too common situation is the result of two manufacturers using completely different PID algorithms.


Believe it or not, there are no adhered to industry standards that define how a PID controller should work, what algorithm it uses and what the various configurable constants should be called.

The result is that you can upgrade a PID controller to a new model or manufacturer, copy the exact P, I and D settings over, and end up with a completely out-of-control process.

We live in a world where all vendors implement the PID control algorithm with different degrees of simplicity and functionality.

This means that it is essential to first identify and then understand the controller type you are tuning.

The variations that we need to identify, because they will affect the tuning, are summarized in this table:



pid tuning algorithms


That means that there are 3 x 2 x 4 x 2 = 48 different combinations of units and algorithms that any one controller can use!

What are the chances that when PID loop tuning, the controller you are using has the same units and algorithms as the next guy? A bit less than getting green on the roulette table!

practical pid tuning


This means, of course, that you have to know:

And then convert the tuning constants to your algorithm and your units.


The PID Tuning Blueprint walks you step-by-step through:



And the upgraded 'pro package' version of the toolkit lets you use PID Simulation to make any learners' mistakes at your desk, not on the plant!