Справочник Пользователя для Mitsubishi Electronics FX5

9 PID CONTROL FUNCTION
9.3 How to Use PID Instruction

Expression for calculating the measured value (after the filter) in sampling at this time
(PVnf)

The value "PVnf" is obtained from the following expression based on the read measured value.
Measured value after filter: PVnf = PVn+L (PVnf-1-PVn)

9.3

How to Use PID Instruction

This instruction executes PID control which changes the output value according to the input variation.
For details on the PID instruction, refer to the following manual.
MELSEC iQ-F FX5 Programming Manual (Instructions, Standard Functions/Function Blocks)

Setting data

■Descriptions, ranges, and data types

■Applicable devices

*1 Only D, SD, R can be used.

Processing details

• Once the target value (s1), measured value (s2) and PID parameters (s3) to (s3)+6 are set and the program is executed,

the operation result (MV) is transferred to the output value (d) at every sampling time. The sampling time is specified by
(s3)

PVn:

Measured value in sampling at this time

Filter coefficient

PVnf-1:

Measured value in previous cycle (after filter)

Ladder diagram

Structured text

ENO:=PID(EN,s1,s2,s3,d);

FBD/LD

Operand

Description

Range

Data type

Data type (label)

(s1)

Device number storing the target value (SV)

-32768 to +32767

16-bit signed binary

ANY16

(s2)

Device number storing the measured value (PV)

-32768 to +32767

16-bit signed binary

ANY16

(s3)

Device number storing PID parameters

1 to 32767

16-bit signed binary

ANY16

(d)

Device number storing the output value (MV)

-32768 to +32767

16-bit signed binary

ANY16

Operand Bit

Word

Double word Indirect

specification

Constant

Others

X, Y, M, L, SM,
F, B, SB, S

U\G T, ST,

C, LC

T, ST, C, D,
W, SD, SW, R

U\G Z

K, H E

(s1)







(s2)







(s3)







(d)







(s1)

(s2)

(s3)

(d)

ENO

Command input

Target value (SV)

Measured value (PV)

Parameters

Output value (MV)

PID

(s1)

(s2)

(s3)

(d)