ST_ParameterSetsPID

Overview

Type:	Structure
Available as of:	V1.0.1.0

Description

The Structure ST_ParameterSetsPID provides five different PID parameter sets.

Structure Elements

Name	Data type	Description
stDefault	ST_PID	Default parameter set: rKp = 2, rTn := 200, rTv := 0, rTd = 0
stCustom	ST_PID	User-defined parameter set. This parameter set provides the PID parameters specified by your application.
stSlow	ST_PID	Parameter set for slow control. This parameter set provides the conservative variant of the parameters determined by auto-tuning. These parameters should reduce the overshoot.
stMedium	ST_PID	Parameter set for medium control. This parameter set provides the medium variant of the parameters determined by auto-tuning.
stOffensive	ST_PID	Parameter set for aggressive control. This parameter set provides the aggressive variant of the parameters determined by auto-tuning. These parameters should reach the set point faster. However, a greater overshot for the process value must be taken into account.

NOTE: If auto-tuning was successfully executed, the PID parameter sets for stSlow, stMedium, or stOffensive are filled in automatically.

NOTE: The determined parameters are not saved permanently. This means, that these parameters need to be reinitialized after a controller power cycle. The application needs to handle them, for example, saving into a file or declaring as retained.

The PID parameter calculation takes into account the current cycle time of the system. A re-execution of auto-tuning is required if the cycle time was changed.

The derivative (rTv) and damping (rTd) will not be calculated after auto-tuning has finished. These parts of the PID control need to be set by the application.