Mitsubishi Q2ACPU User Manual page 25

2. OVERVIEW
(3)
(4)
(5)
Selection of program execution type that is appropriate for the control has been
realised.
There are four program execution types to be selected as follows.
(a) Initial execution type
This program type is executed once only when the QnACPU is set to RUN.
(b) Scan execution type
This program type is run continually while the QnACPU is in the RUN status.
This is equivalent to a conventional program that runs from step 0 to END
instruction. It is possible to create subroutine programs and interrupt programs
for this type of program.
(c) Low-speed execution type
This is a program type which is executed only during the surplus constant scan
time (process to preset the program execution time for constant scan time) or
during the set execution time of the low-speed execution program.
(d) Stand-by type
This type of program consists entirely of a subroutine program or interrupt
program.
The SFC language MELSAP3 has been supplied.
With enhancement of step attributes and SFC control instructions, MELSAP3 makes
SFC programming even easier.
A software development environment that improves program productivity has been
realized.
(a) In order to enable the design of structured programs, a file format has been
adopted for programs.
What would conventionally have been a single continuous program can now be
handled in a structured way as a number of files.
This allows for design work to be shared by several designers, and allows
management of programs in accordance with functions, processes, or
designers, etc.
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