The sequencer shown advances its position whenever:
A)S1 makes a false to true transition.
B)S2 makes a false to true transition.
C)the PLC is in the run mode.
D)either a or b.

Question

The sequencer shown advances its position whenever: 
A)S1 makes a false to true transition. 
B)S2 makes a false to true transition. 
C)the PLC is in the run mode. 
D)either a or b.

Quizplus · Accepted Answer

The sequencer will advance its position whenever either S1 or S2 makes a false to true transition. Therefore, the correct choice is either a or b, which is represented by answer choice D. The PLC being in run mode is not relevant to the operation of the sequencer, so answer choice C is not correct.

The Sequencer Shown Advances Its Position Whenever