Digital Output : MOTOR

START and STOP are momentary contacts.

This circuit (the MEMORY) is the base of most automated sequences. START and STOP may be registers that evaluate to the conditions for starting and stopping MOTOR.

For example :

RULE START=A&B

RULE STOP = A&C’

The above makes B start MOTOR and C stop MOTOR, but neither one work unless A is true.

(see On-Off control with dead-band for another example)

The RULE shown makes the STOP take precedence over the START. You may want START to override STOP. In which case: