User`s manual

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MELSEC-Q
3 DATA USED FOR PROCESS CONTROL INSTRUCTIONS AND HOW TO
SPECIFY DATA
3 DATA USED FOR PROCESS CONTROL
INSTRUCTIONS AND HOW TO SPECIFY DATA
3.1 Process Control Instructions and Data Configuration
This section explains the data structure (data flow) used for process control instructions.
(a) Configuration when using loop tag
1) The loop units have common storage areas that show the control information. This
collection of common information is called a loop tag and the storage memory is called
the loop tag memory.
2) By monitoring the loop tag, you can monitor and tune the loop (control unit).
Block diagram
Process
control
instruction
Operation
constant 1
Block
memory 1
S.IN S.PHPL S.2PID S.OUT1
Output
Input
Output
Input
Output
Input
Output
Loop tag memory
Process
control
instruction
Process
control
instruction
Process
control
instruction
Operation
constant 2
Block
memory 2
Operation
constant 3
Block
memory 3
Operation
constant 4
Block
memory 4
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