Consider the control sequencer of Figure 9-26. Describe how each of the following faults will affect the operation.

(a) The I3 input of the MUX is shorted to ground.

(b) The connections from sensors 3 and 4 to the MUX are reversed.

Figure 9-26

Transcribed Image Text:

Start pulse T Reset T Q₂ +5 V PRE CLKO CLA K E₂ Ē₂ E. A₂ A₁ 3-line-to-8-line decoder 74HC138 A Q₂ ō PRE JQ₂ CLKO CLR K ACTUATORS Fillvalve 1 Fill valve 2 Drain valve 1 Drain valve 2 Mixer Heater Pump Inverting amplifiers for driving actuators PRE J CLKO CLR K A₁ PHYSICAL PROCESS S₂, lo 4 12 bg la b Sp S₁ S₂ E A₂ Timar Haler Eight-input multiplexer 74HC151 JA₂ Z Se Tamp SENSORS Tank 1 full Tank 2 full Tank 1 empty Tank 2 empty Mix time over Up to temp.. Main tank empty Normally LOW sensor outputs will go HIGH to indicate completion of step