Q 2(a) Generally speaking the sequence of the rungs in a ladder logic programme is not important. Why is this the case? Give a simple example to explain your answer Q2(b) What is interlocking with respect to ladder logic programming and what type of programming does this relate to? Q 2(c) A single industrial robot serves to load and unload four different machines on demand. The industrial robot has its own controller, but overall a programmable logic controller provides supervisory control. While all four machines are running, the robot waits in a ready position that is sensed by the robot input 00. Whenever a machine completes a cycle, it automatically signals to the robot that it needs unloading and reloading. The input signals from the corresponding machines are 01. 02. 03. 04. If the robot is not busy with another machine it will service the requesting machine immediately, restart that machine and return to the ready position all under command of its own controller. But if the robot is busy the requesting machine will have to wait. If several machines are waiting, the order in which they are dealt with is irrelevant. The outputs relating to servicing the corresponding machines are, 21, 22, 23, 24. When the robot has finished servicing a machine, the request input is then turned off automatically. Construct a ladder logic diagram to control the robot. Q 2(d) How does the ladder logic change if the machines are serviced in preference according to the order 01 being the most important, 04 being the least important? Note: once the robot begins servicing a machine it finishes the task before moving on to another. Q 2(0) Give three examples of how you incorporate safety features into the design of an automated system