User guide

Software
890 USE 108 00 August 2001 57
The following table describes Process Control Function Library (PCFL) (Three-
Nodes) and the Ladder Logic Subroutine Instructions in the Compact Instruction
set.
Instruction Description
Process Control
Function Library
(PCFL)
(Three-Nodes)
AIN Scales raw analog input into engineering units for calculations. E984-258/265/275/285
only
AOUT Calculates signals for analog output modules. E984-258/265/275/285 only
ALARM Handles alarm limits on process variables. E984-258/265/275/285 only
AVER Calculates the average of up to four weighted inputs. E984-258/265/275/285 only
CALC Calculates a preset formula with up to four inputs. E984-258/265/275/285 only
EQN A formatted equation calculator used for equations that have four or fewer variables but
does not fit into the CALC format. E984-258/265/275/285 only
DELAY Builds a series of readings for time-delay compensation in the logic. E984-258/265/275/
285 only
INTEG Integrates over a specified time interval. E984-258/265/275/285 only
LIMIT Limits the input to a range between a specified high and low value. E984-258/265/275/
285 only
LLAG Provides dynamic compensation for a known disturbance. E984-258/265/275/285 only
MODE Sets up a manual or automatic station for enabling and disabling data transfers to the
next block. E984-258/265/275/285 only
ONOFF Controls the output signal between fully ON and fully OFF conditions so that you can
manually force the output ON or OFF. E984-258/265/275/285 only
PID Performs closed loop control. E984-258/265/275/285 only
RAMP Ramps up linearly to a target set point at a specified approach rate. E984-258/265/275/
285 only
RATE Calculates the rate of change over the last two input values. E984-258/265/275/285
only
SEL Compares up to four inputs and makes a selection based upon either the highest,
lowest, or average value. E984-258/265/275/285 only
PI Performs simple PID. E984-258/265/275/285 only
KPID Offers a superset of the functionality of the PID function. E984-258/265/275/285 only
RATIO Provides a four-station ratio controller. E984-258/265/275/285 only
TOTAL Provides a material totalizer for batch processing reagents. E984-258/265/275/285 only
Ladder Logic
Subroutine
Instructions
(Two-Nodes)
JSR Jumps from scheduled logic scan to a ladder logic subroutine