Mitsubishi Electric MELSEC iQ-R Series, Programming Manual

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10 PID CONTROL INSTRUCTIONS
10.1 Overview
PID control procedure
Create a program for PID control following the procedure below. (Devices are used in the procedure.)
Programming procedure
PID control data change
Setting PID control data
Set PID control data in a word device.
PID operation (exact differential)
Executing the PIDINIT(P) instruction
Execute the PIDINIT(P) instruction.
PID operation (inexact differential)
Executing the S(P).PIDINIT instruction
Execute the S(P).PIDINIT instruction.
Registering PID control data
The PID control data set in the word device is
written to the CPU module.
Setting an initial processing flag value
Set an initial processing flag value in I/O data.
Set value (SV) change
Setting a set value (SV)
Set a set value (SV) in I/O data.
Manipulated value (MV) calculation
mode change
Manual mode
No (Automatic mode)
Selecting an automatic mode
Set 1 (automatic mode) to the manual/automatic
selection area in I/O data.
Yes (Manual mode)
Selecting a manual mode
Set 0 (manual mode) to the manual/automatic
selection area in I/O data.
Reading/setting the process value (PV)
Read out data from the A/D converter module,
and store it in I/O data.
Setting a manual manipulated value (MV
MAN
)
Set a manual manipulated value (MV
MAN
) in I/O data.
PID operation (exact differential)
PID operation (inexact differential)
Execute the PIDCONT(P) instruction.
Executing the PIDCONT(P) instruction
Executing the S(P).PIDCONT instruction
Execute the S(P).PIDCONT instruction.
Performing PID operation
PID operation is performed in accordance with the
PID control data and I/O data set in the word device.
Outputting the manipulated value (MV)
Read out the calculated manipulated value (MV),
and write it to the D/A converter module. The calculated manipulated value (MV) is stored in I/O data.