Figure 1 shows The process involves pumping fluid from tank A to tank B. L1 Inputs فلم Stop Start PS1 PS2 PS3 PS1 Tank A Pumb PS2 PS3 Tank B The operation of the process can be summarized as follows: ■ Before starting, PS1 must be closed. When the start button is pushed, the pump starts. The button can then be released and the pump continues to operate. When the stop button is pushed, the pump stops. PS2 and PS3 must be closed 5 s after the pump starts. If either PS2 or PS3 opens, the pump will shut off and will not be able to start again for another 14 s.