Fnc 88 - Pid / Pid Control Loop - Mitsubishi Electric MELSEC FX3U Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
16.9 FNC 88 – PID / PID Control Loop
Outline
This instruction executes PID control which changes the output value according to the input variation.
1. Instruction format
FNC 88
PID
2. Set data
Operand type
S
S
1 1
S
S
1 2
S
3
S
D
1
3. Applicable devices
Bit Devices
Oper-
and System User
Type
X Y M T C S D .b KnX KnY KnM KnS T C D R U \G
S S
1 1
S
S
1 2
S S
2 3
S
D
1
: This function is supported only in FX
Explanation of function and operation
1. 16-bit operation (PID)
When the target value
program is executed, the operation result (MV) is stored to the output value
.
S
3
Command
input
FNC 88
PID
Mnemonic
16-bit Instruction
9 steps PID
Data register number storing the target value (SV)
Data register number storing the measured value (PV)
Data register number storing a parameter
Data register number storing the output value (MV)
Digit Specification
/FX
3U
, measured value
S
1
S S S
1 2 3
16 External FX Device – FNC 80 to FNC 89
→ For details, refer to the Analog Control Edition.
Operation Condition
32-bit Instruction
Continuous
Operation
Description
Word Devices
Special
System User Index
Unit
V Z Modify K H
PLCs.
3UC
, and parameters
S
2
D
Output value (MV)
Parameter
Measured value (PV)
Target value (SV)
16.9 FNC 88 – PID / PID Control Loop
Mnemonic Operation Condition
−
Data type
16-bit binary
16-bit binary
16-bit binary
16-bit binary
Others
Con- Real Charac-
stant Number ter String
E " "
to +6 are set and a
S S
3 3
at every sampling time
D
11
12
13
14
15
Pointer
P
16
17
18
19
20
495