Omron CS1G/H-CPUxx-EV1 Programming Manual page 82

Basic Concepts
46
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.
0000
00
0000 0002
01 01
4. The same output bit cannot be programmed in an output instruction more
than once. Instructions in a ladder program are executed in order from the
top rung in a single cycle, so the result of output instruction in the lower
rungs will be ultimately reflected in the output bit and the results of any pre-
vious instructions controlling the same bit will be overwritten and not out-
put.
5. An input bit cannot be used in an OUTPUT instruction (OUT).
6. 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.
Section 2-1
0000 0002 0000
03 01 04
(Output bit)
0000
00
(Output bit)
0000
00
(Input bit)
0000
00