How To Use Pid Instruction - Mitsubishi Electric MELSEC iQ-F FX5 User Manual

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)
PVn: Measured value in sampling at this time
L: Filter coefficient
PVnf-1: Measured value in previous cycle (after filter)
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)
Ladder diagram
FBD/LD
EN ENO
s1 d
s2
s3
Setting data
■Descriptions, ranges, and data types
Operand Description
(s1) Device number storing the target value (SV)
(s2) Device number storing the measured value (PV)
(s3) Device number storing PID parameters
(d) Device number storing the output value (MV)
■Applicable devices
Operand Bit
X, Y, M, L, SM,
F, B, SB, S

(s1)

(s2)

(s3)

(d)
*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).
Command input
9 PID CONTROL FUNCTION
56
9.3 How to Use PID Instruction
(s1) (s2) (s3) (d)
Word
T, ST, C, D, W, U\G
SD, SW, R
*1
 
*1
 
*1
 
*1
 
PID (s1) (s2)
Structured text
ENO:=PID(EN,s1,s2,s3,d);
Range
-32768 to +32767
-32768 to +32767
1 to 32767
-32768 to +32767
Double word Indirect
Z LC LZ
  
  
  
  
(s3) (d)
Output value (MV)
Parameters
Measured value (PV)
Target value (SV)
Data type Data type (label)
16-bit signed binary ANY16
16-bit signed binary ANY16
16-bit signed binary ANY16
16-bit signed binary ANY16
Constant
specification
K, H E
  
  
  
  
Others
$
 
 
 
 