Toshiba PROSEC T3H - Manual (Page 53)

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