easylearningacademy

The washing machine is an example of a  sequential control system.  A system operating with sequential control is one where a number of preset operations are performed in sequence.  The control may be implemented as  event-based,  where the next action cannot be performed until the previous action is completed.  Another mode of sequential control is termed  "time-based",  where the operations are sequenced with respect to time. Example: An example of a time-based sequential control system is shown in the following Figure 1. The pump (fill valve) is switched ON for a particular time to fill enough water into the tank to fill it to approximately the correct level. Following this, the pump is switched OFF.   Figure 1: Time-based sequential control Among these two modes,  event-based control  is intrinsically  more reliable  than time-based control.  An example of an event-based sequential control system is a washing machine. In this system, a number of operations or events h