14.1
Operands of the PID Function
The PID function compares feedback from
a process variable (PV) with a desired
process set point (SP) and updates a
control variable (CV) based on the error.
The PID function uses PID loop gains and
other parameters stored in a 40-word
reference array of 16-bit integer words to
solve the PID algorithm at the desired time
interval.
14.1.1
Parameters of the PID Function Block
Para-meter
Description
Allowed Types
Allowed Operands
Optional
Address
(????)
Location of the PID reference array,
which contains user-configurable and
internal parameters, described in the
section,
later in this chapter. 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
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
When energized to 1 (through a
contact), the PID function block is in
manual mode. If this input is 0, the PID
function block is in automatic mode.
NA
Flow
No
UP
If energized along with MAN, increases
the control variable by 1 CV count per
solution of the PID function.
NA
Flow
No
DN
If energized along with MAN, decreases
the control variable by 1 CV count per
solution of the PID function.
NA
Flow
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
274
GFK-1503E
VersaMax PLC User Manual
For public disclosure
Summary of Contents for VersaMax PLC
Page 16: ...Notes 16 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 38: ...Notes 38 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 50: ...Notes 50 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 92: ...Notes 92 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 112: ...Notes 112 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 224: ...Notes 224 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 292: ...Notes 292 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 316: ...Notes 316 GFK 1503E VersaMax PLC User Manual For public disclosure ...
Page 317: ......