
1.OVERVIEW OF PMC B-63983EN/02
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1.4.4.2 Subprogramming and nesting
Function
A conditional call (or unconditional call) is coded in the main program,
and the name of a subprogram to be executed is specified. In the
subprogram, the subprogram name and a ladder sequence to be
executed are coded.
When a conditional call specifying Pn (representing a program name)
is made, a subprogram named Pn is called and executed.
A subroutine name can be assigned by adding a symbol or comment to
Pn.
In the example shown in Fig. 1.4.4.2 (a), the main program calls three
subprograms. These calls are all conditional calls. Subprogram P1 is
named SUBPRO. Subprogram P1 calls subprogram PROCS1
unconditionally.
Fig. 1.4.4.2 (a) Example of subprogramming and nesting