What component triggers the LAST step in the time-driven sequence?

The component that triggers the LAST step in the time-driven sequence is the status of the timers, specifically TIMERS[1].DN. In programmable controller systems, timers are essential elements used to control the timing of operations. The DN (Done) bit of a timer indicates that the timer has reached its preset time and, consequently, has completed its counting period.

When you are working with a time-driven sequence, the logic typically relies on the timing of events. TIMERS[1].DN signifies that the events associated with that particular timer have finished executing. In this context, once this timer has completed its designated time duration, it sends a signal that triggers the last step in the sequence, thus facilitating controlled and sequenced operations as designed in the program.

The other options, while they may have a role in the overall process, do not specifically indicate the completion of the timing sequence that leads to the last step. PB1 typically refers to a push button which might start an action but does not necessarily indicate that the timing step has completed. Pumps P1 and P2 represent physical outputs that could be controlled during the process but, again, do not serve as the completion indication necessary for reaching the last step in a time-based sequence. Therefore, understanding