Q $3($a$)[6$ Marks$]$ Explain how a programmable logic controller $($PLC$)$ controls an automated process in terms of inputs and outputs. Why is the program sequence often irrelevant? Q $3($b$)[4$ Marks$]$ What is the difference between staged programming and standard programming in ladder logic? Q $3($c$)[8$ Marks$]$ Show how to create a memory function in ladder logic with a simple set switch S and a reset switch R$.$ Explain how your ladder logic works. Q $3($d$)[7$ Marks$]$ What adaptation would be required to make the ladder logic for the memory developed in Q$3$c on$-$dominant, i$.$e$.$ where the set function takes precedence over the reset function? Explain how your ladder logic works. $[$End of Question $3]$