A mixing vat has an inlet valve, an outlet valve, a mixing motor, and a single level detecting switch (Figure 12.38). Both valves are opened by solenoids. The level switch closes when the vat is full and stays closed until the vat is empty. Draw a PLC ladder logic diagram to do the following:
a. When the start button is pushed, the inlet valve opens until the vat is full.
b. The mixer motor comes on for 5 min.
c. The outlet valve opens until the vat is empty.
