Delta MS300 Series User Manual page 685

Chapter 16 PLC Function ApplicationsMS300
16-4-3 Overview of PLC ladder diagram editing
The program editing method in WPLSoft begins from the left busbar and proceeds to the right busbar
(the right busbar is not visible in WPLSoft). Continue to the next row after completing each row; there
are a maximum of 11 contacts on each row. If this is not sufficient, WPLSoft generates a continuous
line to indicate the continued connection, so that you can add more devices. A continuous series of
numbers is generated automatically and you can use identical input points repeatedly (as shown in
the following diagram).
The PLC scans a ladder diagram programs from the upper left corner to the lower right corner. The
coils and application command computing box are handled in the output, and in the ladder diagram
are placed on the farthest right of a rung. Taking the diagram below as an example, we can analyze
the procedural sequence of the ladder diagram. The number in the upper right corner gives the
sequential order.
Explanation of
command
sequence
1 LD X0
2 OR M0
3 AND X1
4 LD X3
AND M1
ORB
5 LD Y1
AND X4
6 LD T0
AND M3
ORB
7 ANB
8 OUT Y1
TMR T0 K10
Figure 16-27
Figure 16-28
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