Honeywell EXCEL 5000 User Manual page 190

ALPHABETIC REFERENCE
PID Operation
PID Schematic
Internal Parameters
74-5577–33 (US)
EN2B-0184 GE51 R0518 (Europe)
For more information on PID operation, see the PID Operation section following this
description of the inputs, outputs, and internal parameters.
Inputs Two analog inputs, where:
X = Controlled variable, for example, room temperature sensor.
W = Reference variable, for example, room temperature setpoint.
You can enter the reference variable (W) as a parameter (engineering unit index
number and value).
Output One analog output (Y). The output is the correcting variable that maintains the
setpoint (reference variable). The output is usually a controller output signal that
repositions an actuator.
The following schematic illustrates the formulas used in the PID controller:
The internal parameters dialog box defines the proportional, integral, and derivative
terms as well as minimum and maximum output values that limit the positioning
signal (Y). For additional information, see the PID Plus section.
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EXCEL CARE CONTROL ICONS