Rievtech PR-12 Series, User Manual And Programmers Manual

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6.18 Subroutine
6.18.1 Using subroutine
Subroutine is used for program partitioning.When the main program calls subroutine
and performs the subroutine,subroutine executes all instructions to the end.Then,
the system returns to the main program.
Subroutine is used for program partitioning.It helps to read and manage programs. It
also helps to debug and maintain programs.You can use PLC more effectively by using
subroutine.Because all of the subroutine blocks are not scanned when they are not
called.
If the subroutine only references parameters and local memory,then the subroutine
can be moved.In order to move the subroutine,you can not use any global variables /
symbols (I, Q, M, SM, AI, AQ, V, T, C, S, AC absolute address).If the subroutine does
not call parameters (IN, OUT, or IN_OUT) or only uses local variables,You can export
the subroutine and import it into another project.
Conditions of using subroutine:
1.Create a subroutine
2.Define parameters in the local variable table.
3.Call subroutine from the appropriate POU (from the main program or another
subroutine)
Using subroutine does not save or restore the accumulator.