In steady-state condition with correct tuning, the error in a PID loop is ideally?

Multiple Choice Questions Automation MCQ
1

Question:

In steady-state condition with correct tuning, the error in a PID loop is ideally?

Options:

A) Maximum
B) Zero
C) Oscillating
D) Negative

View Answer

:white_check_mark: Correct Answer: B) Zero

:magnifying_glass_tilted_right: Detailed Explanation

In steady-state operation with proper PID tuning (including integral action), the error:

Error = SP - PV

is ideally zero.

This means:

  • The process variable (PV) equals the setpoint (SP).
  • No continuous deviation exists.
  • The integral term has adjusted the output to remove any steady-state offset.

:repeat_button: Why Integral Action Matters

In proportional-only control, some steady-state error (offset) remains.
With PID (or at least PI) control, integral action accumulates past error until the deviation becomes zero.

:cross_mark: Why Other Options Are Incorrect

A) Maximum → Indicates large deviation; not steady state.
C) Oscillating → Indicates instability or poor tuning.
D) Negative → Error sign depends on PV vs SP, but steady-state ideally means zero error.

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