Mitsubishi Electronics FX3G User Manual
476
FX
3S
/FX
3G
/FX
3GC
/FX
3U
/FX
3UC
Series
Programming Manual - Basic & Applied Instruction Edition
16 External FX Device – FNC 80 to FNC 89
16.9 FNC 88 – PID / PID Control Loop
16.9
FNC 88 – PID / PID Control Loop
Outline
This instruction executes PID control which changes the output value according to the input variation.
→ For details, refer to the Analog Control Edition.
1. Instruction format
2. Set data
3. Applicable devices
S
1: This function is supported only in FX
3G
/FX
3GC
/FX
3U
/FX
3UC
PLCs.
S
2: This function is supported only in FX
3U
/FX
3UC
PLCs.
Explanation of function and operation
1. 16-bit operation (PID)
When the target value
, measured value
, and parameters
to
+6 are set and a program is
executed, the operation result (MV) is stored to the output value
at every sampling time
.
Operand type
Description
Data type
Data register number storing the target value (SV)
16-bit binary
Data register number storing the measured value (PV)
16-bit binary
Data register number storing a parameter
16-bit binary
Data register number storing the output value (MV)
16-bit binary
Oper-
and
Type
Bit Devices
Word Devices
Others
System User
Digit Specification
System User
Special
Unit
Index
Con-
stant
stant
Real
Number
Charac-
ter String
Pointer
X Y M T C S D .b KnX KnY KnM KnS T C D
R
U \G
V Z Modify K H
E
" "
P
S1
S2
S1
S2
S1
S1
S2
FNC 88
PID
−
Mnemonic
Operation Condition
16-bit Instruction
9 steps PID
Mnemonic
Operation Condition
Continuous
Operation
32-bit Instruction
S
1
S
1
S
1
S
2
S
3
S
1
D
S
1
S
1
S
1
S
2
S
2
S
3
S
1
D
S
1
S
2
S
3
S
3
D
S
3
Command
input
FNC 88
PID
S
3
S
2
S
1
D
Target value (SV)
Measured value (PV)
Parameter
Output value (MV)