Standard
Rll Instructions
5–96
Standard RLL Instructions
Program Control Instructions
Program Control Instructions
The For and Next instructions are used to
execute a section of ladder logic between
the For and Next instruction a specified
numbers of times. When the For
instruction is enabled, the program will
loop the specified number of times. If the
For instruction is not energized the section
of ladder logic between the For and Next
instructions is not executed.
For / Next instructions cannot be nested.
The normal I/O update and CPU
housekeeping is suspended while
executing the For / Next loop. The program
scan can increase significantly, depending
on the amount of times the logic between
the For and Next instruction is executed.
With the exception of immediate I/O
instructions, I/O will not be updated until
the program execution is completed for
that scan. Depending on the length of time
required to complete the program
execution, it may be necessary to reset the
watch dog timer inside of the For / Next
loop using the RSTWT instruction.
A aaa
FOR
NEXT
Operand Data Type DL05 Range
A aaa
V memory V All (See page 4–28)
Constant K 1–9999
For / Next
(FOR)
(NEXT)
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