Micromod MOD: Modcell 2050R Users Guide - Manual (Page 163)

IB-23C650
TUNING
AUTOMATIC TUNING
Automatic tuning (autotune) is an on-demand user activated feature which
automatically calculates either PI or PID response values based on process
reaction during an autotune cycle. This is accomplished by manipulating the
controller output to effect a periodic response by the intended process. The
autotune cycle requires 6 process oscillations to determine the tuning
parameters. The controller output and a typical process response are as
shown in Figure 18. After successful completion of the autotune cycle,
calculated response values are entered into the control algorithm calculations
and the controller is operational in the automatic mode with the new values.
The parameter values may be observed and/or changed in the TUNE MENU.
Automatic tuning is not applicable to dual output (heat/cool) or on-off control.
Figure 18. Typical Process Variable and Controller Output
Response During Autotune Execution
Setup Procedure
In order to use the autotune feature, it must be enabled in the BASE CFG
MENU. The procedure in Table 13 explains various rules and guidelines
which apply to the autotune setup. Autotune setup also requires user input to
define certain operating parameters and constraints. Table 13 provides a
detailed description of each of the five setup parameters.
157