
Notice: Artisan Controls Corporation assumes no responsibility for customers applications or product design. The information and data contained herein is the sole and
exclusive property of Artisan Controls Corporation. Any duplication, misuse, or conversion of this information without the express written consent of Artisan Controls
Corporation is illegal and will result in damages including court costs and attorney fees being assessed against the party misusing this property
Artisan Controls Corporation, 111 Canfield Ave., Bldg B15-18, Randolph, NJ 07869
www.artisancontrols.com
5400 Controller User’s Manual
Table of Contents
Page 17
The PID auto tune in the 5400 controller is a customized Ziegler - Nichols tuning based on the system
performance using relay step / closed loop analysis. The controller uses a setpoint calculated from the
setpoint value entered in the PID Configuration window and then calculates positive and negative offsets
based on that setpoint. The heating output is driven between the high and low percentages, switching back
and forth based on the setpoint and offsets on a thermostatic basis. The auto tune systems runs a total of 6
cycles, 3 to allow the system to stabilize and then 3 to measure the performance of the system and
determine the performance of the system. From these values the Kp, Ki, and Kd constants are calculated.
The closer these percentages are to each other the more accurately the auto tune system can determine
the performance of the environment. On systems with higher heat losses the High percentage needs to be
high in order to get a reasonable change of the temperature from low to high, and conversely highly
insulated systems with low heat loss will need the Low percentage to be lower for the same reason.
PID AUTO TUNING
The High % value can be changed by pressing the
[edit] button which displays a numeric entry
window. The same method is used to edit the Low
% value. The upper window on the right side
displays the real-time output percentage and the
window below is the temperature. The two
percentage values are saved in the non-volatile
memory with the other PID configuration
information to simplify additional auto tuning cycles
for maximum control tuning.
Pressing the [START] button begins the auto tune
process, the Status window displays “Cycling”
during the 3 stabilization cycles and “Measuring”
during the 3 analysis cycles. Once the process is
complete the Auto Tune Results window is
displayed showing the current and new PID
constants along with the calculated system
performance values (Ku & Pu). Press the [USE]
button to save these new values and the controller
returns to the PID Configuration window to allow
these new constants to be tested and/or saved.