
106
When the execution condition is OFF, ORW(43) is not executed. When the
execution condition is ON, ORW(43) logically OR’s the contents of I1 and I2
bit-by-bit and places the result in R.
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
15
00
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1
1
0
1
1
1
0
1
1
1
0
1
1
1
0
1
15
00
15
00
I1
I2
R
Example
ER:
Indirectly addressed DR word is non-existent. (Content of
*
DR word
is not BCD, or the DR area boundary has been exceeded.)
EQ:
ON when the result is 0.
3-7-32
STEP DEFINE and STEP START-STEP(04)/SNXT(05)
B: Control bit
Output bits, work bits, DR, LR
Ladder Symbols
Definer Data Areas
STEP(04) B
STEP(04)
B: Control bit
Output bits, work bits, DR, LR
SNXT(05) B
Control bits within one section of step programming must be sequential and
from the same word.
STEP(04) uses a control bit that is either an output bit, a work bit, or a bit in
the LR or DR area to define the beginning of a section of the program called
a step. STEP(04) does not require an execution condition, i.e., its execution
is controlled through the control bit. To start execution of the step, SNXT(05)
is used with the same control bit as used for STEP(04). If SNXT(05) is ex-
ecuted with an ON execution condition, the step with the same control bit is
executed. If the execution condition is OFF, the step is not executed. The
SNXT(05) instruction must be written into the program so that it is executed
before the program reaches the step it starts. It can be used at different loca-
tions before the step to control the step according to two different execution
conditions. Any step in the program that has not been started with SNXT(05)
will not be executed.
Once SNXT(05) is used in the program, step execution will continue until
STEP(04) is executed without a control bit. STEP(04) without a control bit
must be preceded by SNXT(05) with a dummy control bit.
Execution of a step is completed either by execution of the next SNXT(05) or
by turning OFF the control bit for the step. When the step is completed, all of
Description
Flags
Limitations
Description
Instruction Set
Section 3-7