Mitsubishi Electronics MELSEC-F Manuel D’Utilisation

FX

3G

/FX

3U

/FX

3UC

 PLC User's Manual - Analog Control Edition

PID Instruction (FNC 88)

2 How to Use PID Instruction

FX

3U

-4A
D

-P

NK

          
         

-A

D

P

FX

3U

-4AD

-TC

        

        

   -

A

D

P

PI

D

 In

st

ru

ctio

n

           (F

N

C

 88
)

1. Instruction format

2. Set data

3. Target devices

S : Only available for FX

3U

 and FX

3UC

 PLCs.

Once the target value 

, measured value 

 and PID parameters 

 to 

+ 6 are set and the

program is executed, the operation result (MV) is transferred to the output value 

 at every sampling

time. The sampling time is specified by 

Data register storing the target value (SV)

Binary 16-bit

Data register storing the measured value (PV)

Binary 16-bit

Data register storing PID parameters

Binary 16-bit

Data register storing the output value (MV)

Binary 16-bit

System User

Digit Specification

System User

Special 

Unit

Index

Con-
stant

Real 

Num-

ber

Char-

acter 

String

Poin-

ter

X Y M T C S D .b KnX KnY KnM KnS T

C

D

R U \G

V

Z

Mod-

ify

K H

E

" "

P

S

S

S

32-bit

lnstruction

⎯

Mnemonic Operation Condition

FNC 88

PID

PID

16-bit

lnstruction

9 steps PID

Continuous

Operation

Mnemonic Operation Condition

  S

S

1

S

2

S

3

D

  S

S

1

S

2

S

3

D

S

1

S

1

S

2

S

2

S

3

S

3

S

3

S

3

S

3

D

S

3

S

3

Command

input

FNC 88

PID

S

3

S

2

S

1

D

Target

value

(SV)

Measured

value

(PV)

PID

Parameters

Output

value

(MV)