How to Use the Step Ladder Program Block
Appendix 1
214
To break up a Step Ladder Program, use the STEP command (21). (The default step for the Step Ladder
Program block is the constant operation step STEP00.)
When run/stop command S1 (ITEM008) of the Step Ladder Program block turns ON, STEP00 (constantly
available step) and STEP01 (first step of step sequence) operate. Program execution is made to move to
other steps (also to specified STEPs in other Step Ladder Program blocks) when the input conditions are
satisfied during STEP01.
STEP01 onwards only can also be described without describing STEP00 (constantly available step).
When contact input to stop move to next step switch S2 (ITEM009) in the entire Step Ladder Program block
turns ON, program execution pauses at the currently operating STEP. Output is also held at the current state
at this time. When contact input to S2 (ITEM009) returns to OFF, program execution is resumed from the
STEP that was paused.
Multiple
steps
STEP00
STEP01
STEP02
STEP03
STEP04
ITEM
Command
Operand
011
01 (LOAD)
012
03 (AND)
013
07 (OUT)
ITEM
Command
Operand
014
21 (SP)
01
From here on declared to STEP01
015
01 (LOAD)
016
03 (AND)
017
13 (SET)
A
Move to next STEP02 at
establishment of final input
conditions (execution of SET)
ITEM
Command
Operand
018
21 (SP)
02
From here on declared to STEP02
019
01 (LOAD)
020
03 (AND)
021
13 (SET)
B
Move to next STEP03 at
establishment of final input
conditions (execution of SET)
indicates operation when run/stop command S1
turns ON.