Honeywell Experion PID parameters explained
Honeywell controllers traditionally express proportional action as a proportional band and reset as minutes per repeat. That combination inverts the direction of a change twice over relative to a gain-and-repeats-per-minute system.
On these systems, making a loop more aggressive proportionally means reducing the number, and making integral action faster also means reducing the number. Both are the opposite of what an engineer arriving from a gain-based system would expect, which is exactly why PIDSnap captures the convention once per plant and phrases every instruction accordingly.
Which direction makes the action stronger
On your system a LOWER proportional number means MORE aggressive proportional action. Proportional band is the inverse of gain.
Reset is in minutes/repeat, so a LOWER number means FASTER integral action.
This is the single most consequential thing to get right. Proportional band and gain move in opposite directions, and so do repeats-per-time and time-per-repeat. An engineer who has moved from one system to another and carried the old habit across will make loops worse while believing they are improving them.
- Proportional term: proportional band
- Reset units: minutes/repeat
- Rate units: minutes
- Algorithm form: ideal noninteracting
When a copied set hunts or sits off setpoint
A gain-based set typed onto a Honeywell faceplate as if the band were gain is the usual origin of a loop that hunts on Experion and was stable on the source. Convert first. Offset that will not close is reset too slow, or a valve that will not seat — not a missing derivative.
Honeywell blocks also carry a configured PID deadband: a gap the controller ignores so noise does not move the valve. That is not valve deadband. Measure the flat spot on a reversal before you retune. If it matches the configured gap, the block is doing what it was told.
Why the algorithm form matters
The algorithm form matters because the same three numbers behave differently in each. In the series (interacting) form the derivative term multiplies the proportional-plus-integral term, so changing rate also changes the effective gain and reset. In the ideal (non-interacting) form the three terms are independent of each other but all scaled by gain. In the parallel (independent) form even that scaling is absent — gain does not affect integral or derivative action at all. Moving a tuning set between systems without converting for form is one of the commonest ways a loop that worked on one plant fails on another.
Before you change anything
Confirm the units on the actual controller rather than trusting the platform default. Systems get configured in unusual ways, engineering units get changed during a migration, and a controller imported from another site may carry conventions from there.
The fastest check is to make a small deliberate change and watch which way the loop responds. If it gets more aggressive when you expected less, the convention is not what you assumed.
Questions that come up
Does Honeywell always use proportional band?
It is the traditional convention and remains common, but configurations vary — particularly on newer systems and on controllers migrated from other platforms. Read the units off the faceplate rather than assuming.
What are Honeywell Experion PID parameters?
Proportional band (inverse of gain), reset in minutes per repeat, and rate as derivative time. Reducing band or reducing reset both make the loop more aggressive — the opposite of a gain-and-repeats system.
What are Honeywell proportional band, reset and rate?
Proportional band is the inverse of gain, reset is minutes per repeat, and rate is derivative time. Reducing band or reducing reset both make the loop more aggressive — the opposite of a gain-and-repeats system.
Related
Written by PIDSnap control engineering. Published 2026-08-01, last reviewed 2026-11-06.