Gain_Pid Data Type; At_Param Data Type - Allen-Bradley Micro800 General Instructions Manual

Chapter 20
Proportional Integral Derivative (PID) instruction
Parameter
DirectActing
ProportionalGain
TimeIntegral
TimeDerivative
DerivativeGain
Parameter
Load
Deviation
Step
ATDynamSet
ATReset
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GAIN_PID data type

The following table describes the GAIN_PID data type.
Data type Description
BOOL The type of acting:
• TRUE - direct acting (output moves same direction as error). That is, the actual process value is greater
than the SetPoint and the appropriate controller action is to increase the output (For example: Chilling).
• FALSE - reverse acting (output moves opposite direction as error). That is, the actual process value is
greater than the SetPoint and the appropriate controller action is to decrease the output (For example:
Heating).
REAL Proportional gain for PID (>= 0.0001).
REAL Time integral value for PID (>= 0.0001).
REAL Time derivative value for PID (> 0.0).
REAL Derivative gain for PID (> 0.0).

AT_Param data type

The following table describes the AT_Param data type parameters.
Data type Description
REAL Load parameter for auto tuning. This is the output value when starting AutoTune.
REAL Deviation for auto tuning. This is the standard deviation used to evaluate the noise band needed for AutoTune.
REAL Step value for AutoTune. Must be greater than noise band and less than ½ Load.
REAL Waiting time in seconds before abandoning auto tune.
BOOL The indication of whether the output value is reset to zero after an AutoTune sequence:
• TRUE - resets output to zero.
• FALSE - leaves 0utput at Load value.
Rockwell Automation Publication 2080-RM001D-EN-E - February 2015