Chapter 7 Programming
7-5
The user program is managed in circuit units. One circuit can describe nine contact points (a-type contact point or b-type
contact point) and seven coils as shown in the figure below.
Figure 7.1 Size of one circuit
Or, one relational box can be described using the width of three contact points. The relational box can be considered as an
a-type contact point that turns on when the conditions in the box are established (Figure 7.2).
Figure 7.2 Example when using a relational box