GE PACSystems RX7i

Chapter 7. PID Built-In Function Block
344 PACSystems* RX7i, RX3i and RSTi-EP CPU Programmer's Reference Manual GFK-2950C
7.1 Operands of the PID Function
7.1.1 Operands for LD Version of PID Function Block
Parameter
Description
Allowed Types
Allowed Operands
Optional
(????)
Instance Variable name of the PID
Parameter Block array, which contains user-
configurable and internal parameters,
described in Reference Array for the PID
Function. Uses 40 words that cannot be
shared.
WORD
R, L, P, W
and symbolic
No
SP
The control loop or process set point. Set
using process variable counts, the PID
function adjusts the output control variable
so that the process variable matches the set
point (zero error).
INT, BOOL array
of length 16 or
more, Constant
All except S, SA, SB,
and SC
No
PV
Process Variable input from the process
being controlled. Often a %AI input.
INT, BOOL array
of length 16 or
more
All except S, SA, SB,
and SC, and
constant
No
MAN
While Power Flow is received, the PID
function block is held in manual mode. If no
Power Flow is received the PID function
block is in Auto mode.
Power Flow
NA
No
UP
While Power Flow is received, the Manual
Command is increased by 1 each user
configured Sample Period.
Power Flow
NA
No
DN
While Power Flow is received, the Manual
Command is decreased by 1 each user
configured Sample Period.
Power Flow
NA
No
CV
The control variable output to the process.
Often a %AQ output.
INT, BOOL array
of length 16 or
more
All except %S and
constant
No