User manual

Basic Instructions
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Syntax of step ladder instruction
SSTP (start step) instruction:
This instruction indicates the start of a process n.
SSTP 1
SSTP 2
SSTP 5
Program
Program
Program
Process 1
Process 2
In a step ladder program, a process n is identified as being from one SSTPn instruction to the next SSTP or
STPE instruction.
No two processes can have the same process number.
The OT instruction can be programmed at the address just after the SSTP instruction.
The SSTP instruction cannot be programmed in sub−program (subroutine or interrupt program area).
The area starting from the first SSTP instruction to the STPE instruction is referred to as the step ladder area.
The programs in this area are all controlled as processes.
Other areas are referred to as ordinary ladder areas.
SSTP 1
SSTP n
STPE
Ordinary ladder area
Ordinary ladder area
Step ladder area
There is a special internal relay that turns on for one scan only when a process on the step ladder starts.
(R9015: step ladder initial pulse relay.) This relay is used to perform operations for only one scan for counter
reset or other such process starts.