Toshiba 6F3B0253 - Manual (Page 221)

6F3B0253
Basic Hardware and Function
219
7. Instructions
FUN 156 PID3 Pre-derivative real PID
Expression
Input − [ A PID3 B
→
C ] − Output
Function
Performs PID (Proportional, Integral, Derivative) control which is a fundamental method of feed-
back control. (Pre-derivative real PID algorithm) This PID3 instruction has the following features.
•
For derivative action, incomplete derivative is used to suppress interference of high-frequency
noise and to expand the stable application range,
•
Controllability and stability are enhanced in case of limit operation for MV, by using digital PID
algorithm succeeding to benefits of analog PID.
•
Auto, cascade and manual modes are supported in this instruction.
•
Digital filter is available for PV.
•
Direct / reverse operation is selectable.
Execution condition
Input Operation Output
OFF Initialization OFF
ON Execute PID every setting interval ON when
execution
Operand
Name Device Register Constant Index
X Y R S T. C. XW YW RW SW T C D I J K
A Top of input data √ √ √ √ √ √ √
B Top of parameter √ √ √ √ √ √ √
C Top of output data √ √ √ √ √ √
Input data Control parameter Output data
A Process input value PVC B Proportional gain K
P
C Manipulation value MV
A+1 A-mode set value ASV B+1 Integral time T
I
C+1 Last error e
n-1
A+2 C-mode set value CSV B+2 Derivative time T
D
C+2 Last derivative value D
n-1
A+3 M-mode MV input MMV B+3 Dead-band GP C+3 Last PV PV
n-1
A+4 MV tracking input TMV B+4 A-mode initial SV ISV C+4 Last SV SV
n-1
A+5 Mode setting MODE B+5 Input filter constant FT C+5 Integral remainder Ir
B+6 ASV differential limit DSV C+6 Derivative remainder Dr
B+7 MMV differential limit DMMV C+7 Internal MV MV
n
A-mode: Auto mode B+8 Initial status STS C+8 Internal counter C
C-mode: Cascade mode B+9 MV upper limit MH C+9 Control interval ∆∆∆∆
t
M-mode: Manual mode B+10 MV lower limit ML
B+11 MV differential limit DMV
B+12 Control interval setting n