Omron CJ1G-CPU series, Programming Manual

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Basic Concepts Section 2-1
3. An input bit must always be inserted before and never after an output in-
struction like an output bit. If it is inserted after an output instruction, then
a location error will occur during a Programming Device program check.
4. The same output bit cannot be programmed in an output instruction more
than once. If it is, a duplicate output bit error will occur and output instruc-
tion programmed first will not operate. The results of the second rung will
be output.
5. An input bit cannot be used in an OUTPUT instruction (OUT).
6. The total number –1 of LD/LD NOT instructions minus one indicating logi-
cal starts must match the total number of AND LD and OR LD instructions
connecting the instruction blocks. If they do not match, then a rung error
will occur during a Programming Device program check.
7. An END(001) instruction must be inserted at the end of the program in
each task.
• If a program without an END(001) instruction starts running, a program
error indicating No End Instruction will occur, the ERR/ALM LED on the
front of the CPU Unit will light, and the program will not be executed.
• If a program has more than one END(001) instruction, then the program
will only run until the first END(001) instruction.
0002
01
0000
00
0000
03
0000
04
0000
01
0002
01
0000
00
0000
00
(Output bit)
(Output bit)
0000
00
(Input bit)
Example
LD A 3
OR B
LD C
OR D
AND LD
2
LD E
OR F
AND LD
OUT G
A
B
C
D
E
F
G