Chapter 16 PLC Function ApplicationsC2000-HS
16-18
Ladder diagram
structures
Explanation of commands Command Using Device
Some basic commands,
applications commands
Some basic
commands
Applications
commands
Inverted logic INV N/A
16-4-3 Overview of PLC ladder diagram editing
The program editing method begins from the left busbar and proceeds to the right busbar (the
right busbar is omitted when editing using WPLSoft). Continue to the next row after completing each
row; there is a maximum of 11 contacts on each row. If this is not sufficient, a continuous line will be
generated to indicate the continued connection and more devices can be added. A continuous series
of numbers will be generated automatically and identical input points can be used repeatedly. See
figure below:
The ladder diagram programming method involves scanning from the upper left corner to the
lower right corner. The coils and applications command-computing box are handled in the output,
and the ladder diagram is placed on the farthest right. Taking the figure below as an example, we can
gradually analyze the procedural sequence of the ladder diagram. The number in the upper right
corner gives the sequential order.
Explanation of
command
sequence
X0 X1 Y1 X4
M0
X3
M1
T0
M3
Y1
TMR
T0
K10
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