Chapter 7. PID Built-In Function Block
GFK-2950C
February 2018
345
7.1.2
Operands for FBD Version of PID Function Block
Parameter Description
Allowed Types
Allowed Operands
Optional
Control
Structure
Variable
Instance Variable name of the PID
Parameter Block array, which contains
user-configurable and internal
parameters, described in
. Uses 40
words that cannot be shared.
WORD
R, L, P, W
and symbolic
No
Function
block solve
order
–
FBD
version
Calculated by the FBD editor. Can be
changed by the user.
NA
NA
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,
SC and constant
No
MAN
When energized to 1 (through a
contact), the PID function block is in
manual
mode. If this input is 0, the
PID block is in
automatic
mode.
BOOL, Power Flow All
No
UP
If energized along with MAN,
increases the control variable by 1 CV
count per solution of the PID function
block.
BOOL, Power Flow All
No
DN
If energized along with MAN,
decreases the control variable by 1
CV count per solution of the PID
function block.
BOOL, Power Flow All
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
Summary of Contents for PACSystems RX7i
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Page 466: ...Chapter 9 Diagnostics GFK 2950C February 2018 451...
