Q$4.$ The Figure below shows a drilling process that needs to be controlled using PLC$.$ The sequence of operation $-$the function description$-$ is as follows:

$1.$ At the beginning of the drilling cycle the Upper Limit Switch is closed

$2.$ The START button starts the drilling cycle $($push button$)$

$3.$ The drill motor M$1$ must start. At the same time, the vertical motor M$2$ must start

to descend the drill

$4.$ The drill will stop at the Lower Limit Switch.

At this time, the vertical motor start to ascend the drill $.$

$5.$ The drill motor must stop just at the upper position. Wait for a new drilling cycle

$6.$ Stop button is optional $($push button$)$

A$.$ List in a table out all input and output devices for this process!

B$.$ Make a ladder logic PLC program for the implementation of the process!