Mitsubishi Electric melsec q03ud(E)cpu - Stand-By Type Program

CHAPTER2 SEQUENCE PROGRAMS
1
2
3
4
5
6
7
8
2.3 Settings When Program is Divided 2.3.3 Stand-by type program
2 - 21
2.3.3 Stand-by type program
(1) Definition
Stand-by type program is executed only when its execution is requested.
This type of program can be changed to any desired execution type by a sequence program
instruction.
(2) Application
(a) Program library
Stand-by type program is used as a program library, a collection of subroutine programs and/or
interrupt programs, and managed separately from a main routine program.
Multiple subroutine programs and/or interrupt programs can be created and managed in a single
stand-by type program.
(b) Program type change
Stand-by type program is used to create and store programs available in all systems. Only required
programs will be executed.
For example, a program preset as a stand-by ("Wait") type program in the PLC parameter dialog
box can be changed to a scan execution type program and executed in the sequence program.
Figure 2.24 Program library using a stand-by type program
P100
I0
P100
I0
Scan execution type program Scan execution type program
Stand-by type program
Main routine
program
Main routine
program
Subroutine
program
Interrupt
program
Subroutine
program
Interrupt
program