Omron SYSMAC C20K Operation Manual page 140

Step Instructions
Precautions
Flags
Interlocks, jumps, SBN(92), and END(01) must not be used within step pro-
grams.
Bits used as control bits must not be used anywhere else in the program un-
less they are used to control the step (see example 3, below).
If IR bits are used for control bits, their status will be lost during any power
interruption. If it is necessary to maintain status to resume execution at the
same step, HR bits must be used.
1811: Step Start flag; turns ON for one cycle when STEP(08) is executed
and can be used to reset counters in steps as shown below if neces-
sary.
0000
0100
1811
Address Instruction
0000 LD
0001 SNXT(09)
0002 STEP(08)
0003 LD
0004 LD
0005 CNT
SNXT(09) 1000
STEP(08) 1000
CP
CNT 01
#0003
R
Operands
0000
1000
1000
0100
1811
01
# 0003
Section 5-18
Start
1000
1811
1 cycle
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