User guide

Temperature Controller iB6 / iB12

6.0 PID Controller Tuning

6.1 Introduction

iB6 and iB12 Temperature Controllers support automatic tuning for control of zones running in

CompuCycle Normal (closed loop) mode.

By default, every iB6 and iB12 controller is configured to execute the Autotune operation the first

time it is powered up, then to disable the Autotune feature, even if Autotune was not successful.

The Autotune operation overwrites any existing proportional band and derivative (rate) parameter

values that were previously configured.

All iB6 and iB12 controllers in a single process should be Autotuned simultaneously, so that

interactions between zones during tuning parallel the interactions expected while the controllers

are in use.

6.2 Procedure for Autotuning

To Autotune:

1) Make sure the controller is in Idle state (only the green C or F LED lit).

2) After configuring any parameters that you want to change from the defaults, enter a setpoint that

is representative of the setpoint you expect to use when the selected zones are in Normal mode

operation.

3) If Autotuning has been attempted in the past, the Autotune feature may be disabled. To force an

Autotune operation, use the Control Config menu to set the PID Autotune parameter to Enable.

4) Cycle the power to the controller.

5) At this point the controller may execute a CompuStep

soft start.

 • Ifyouwantthesoftstarttocontinuetoitsnormalconclusion(recommended),

do not press any buttons.

 • Ifyouwanttoterminatethesoftstart(notrecommended),usethemode

button

to set the selected zones mode to Normal.

Typical Autotune PV Profile

Heat Storage Test

Heat On

Heat Off

Response Test

Starting Conditions Test