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F
Fieldbus
™
OUNDATION
April 2023
Recommended action
Change OUT_SCALE or set values within range.
8.9
Proportional/integral/derivative (PID) function
block
The PID function block combines all of the necessary logic to perform proportional/
integral/derivative (PID) control. The block supports mode control, signal scaling and
limiting, feedforward control, override tracking, alarm limit detection, and signal status
propagation.
Figure 8-12: Proportional/Integral/Derivative (PID) Function Block
•
BKCAL_IN = The analog input value and status from another block's BKCAL_OUT output
that is used for backward output tracking for bumpless transfer and to pass limit status.
•
CAS_IN = The remote setpoint value from another function block.
•
FF_VAL = The feedfoward control input value and status.
•
IN = The connection for the process variable from another function block.
•
TRK_IN_D = Initiates the external tracking function.
•
TRK_VAL = The value after scaling applied to OUT in Local Override mode.
•
BKCAL_OUT = The value and status required by the BKCAL_IN input of another function
block to prevent reset windup and to provide bumpless transfer to closed loop control.
•
OUT = The block output and status.
The block supports two forms of the PID equation: Standard and Series. You can choose
the appropriate equation using the FORM parameter. The standard ISA PID equation is the
default selection.
140
Manual
00809-0500-4881
Emerson.com/Rosemount
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