Delta DVP-PLC, Applications Manual

Page: 18 / 586

1 Basic Principles of PLC Ladder Diagram
DVP-PLC Application Manual
1-14
OR operation upward is not allowed.
Reverse flow
“Reverse flow” exists in the signal circuit from the
beginning of input to output.
The up-right corner should output first.
Combining or editing should be done from the
up-left to the bottom-right. The dotted-lined area
should be moved up.
Parallel operation with empty device is not allowed.
Empty device cannot do operations with other
devices.
No device in the middle block.
Devices and blocks in series should be horizontally
aligned.
Label P0 should be in the first row of a complete
network.
Blocks connected in series should be aligned with
the upmost horizontal line.