User’s Manual
51
2. Expanded Functions
2.4.3 Floating point essential PID (FPID3)
FUN 232
FPID3
Floating point essential PID
Expression
Input
─
[
A+1
⋅
A
FPID3
B+1
⋅
B
→
C+1
⋅
C
]
─
Output
Function
Performs PID (Proportional, Integral, Derivative) control which is a fundamental method of feed-back control.
(Pre-derivative real PID algorithm)
The operation of this FPID3 instruction is the same as the PID3 (FUN156) instruction except for dealing data
as floating point data.
Execution condition
Input Operation Output
OFF Initialization
OFF
ON
Execute PID every setting interval
ON when
execution
Operand
Name
Device
Register
Con-
Index
X Y S L R Z T. C. I O X
W
Y
W
S
W
L
W
R
W
W T C D F I
W
O
W
I J K
stant
A
Top of input
data
√
√
√
√
√
√
√
√
√
√
√
B
Top of
parameter
√
√
√
√
√
√
√
√
√
√
√
C
Top of
output data
√
√
√
√
√
√
√
√
√
√
Input data
Control parameter
Output data
A+1
⋅
A
Process input value
PVC B+1
⋅
B
Proportional gain
K
P
C+1
⋅
C
Manipulation value
MV
A-mode set value
ASV
Integral time
T
I
Last error
e
n-1
C-mode set value
CSV
Derivative time
T
D
Last derivative value
D
n-1
M-mode MV input
MMV
Dead-band
GP
Last PV
PV
n-1
MV tracking input
TMV
A-mode initial SV
ISV
Last SV
SV
n-1
Mode setting
MODE
Input filter constant
FT
Integral remainder
Ir
ASV differential limit
DSV
Derivative remainder
Dr
MMV differential limit
DMMV
Internal MV
MV
n
A-mode: Auto mode
Initial status
STS
Internal counter
C
C-mode: Cascade mode
MV upper limit
MH
Control interval
∆∆∆∆
t
M-mode: Manual mode
MV lower limit
ML
MV differential limit
DMV
Control interval setting
n
