Figure 13.17b shows a possible solution to Example 13.1.
The first three rungs S1, S2, and S3 are used for control of the indicator lights and the power to the rest of the circuit. Momentary closure of switch 1 PB will energize control relay 1 CR, this in turn will close 1 CR NO contacts and open 1 CR NC contacts.
These contacts will perform the following operations: