Reference no: EM132319879

Programmable Logic Controllers (PLC) Assessment - Practical

Scenario (based on the notes you took whilst interviewing your client):

A small business commissions you to automate their process. Until now, they have operated the rebar straightening, cutting and bending machines, which are all installed level to a roller feeder system, manually. It poses a bottleneck in their (largely manual) construction steel production process, so automating these machines are seen to be a required step in growth of the small business, to a point in future when they can afford to buy automated machines.

In the construction industry, steel is cast into concrete slabs, beams and other structures, to give it the required strength and rigidity. The steel mostly used, is called rebar and is a round, ribbed, heat- treated steel that comes in coils as shown below. They are commonly available in diameters ranging from 10mm to 40mm.

Note - For more detailed for scenario see attached file.

Question -

a) Draw a picture (not to scale) of the complete production line, showing all machines, feed tables, air-operated rejector, sensors, clamps etc. and their relative positions.

b) If the control algorithm is written in Codesys and UINT variables are used to indicate the length of the rebar from the roller-wheel length-sensors discussed, calculate the longest square stirrup that can be formed theoretically. Show your calculations and explain your thoughts used in calculating.

c) Calculate the length of the feed roller tables that are required to produce the theoretical largest square stirrup calculated as above.

d) Do you think that the given equipment shown will be able to automatically produce the largest square stirrup calculated above? Why or why not?

e) What are the dimensions of the smallest square stirrup that can be manufacture by this production line? What constraints the dimension of the smallest stirrup most?

f) What is your prediction regarding the influence of the thickness (diameter) and length (mm) of the rebar on measuring the original length of the rebar from the un-coiling machine, before being braked and cut?

g) What additional instrumentation do you find necessary to complete this project?

h) What additional safety measures would you introduce to safeguard employees and machines in this process?

i) Which IEC61131-3 language is best suited as basis for developing this automation system and why?

j) Is the process as it is described, running at its best productivity? Describe at least two interventions that can enhance productivity of the setup.

k) Specify input and output modules that must be ordered for the PLC that will be used in the automation.

l) Write down assumptions that you feel should be taken into account as your final program is assessed.

m) Now use SFC language as a basis, with ST and LD inserts as is best applicable, to develop a program for automation of this process as optimised in (j) above. Copy / paste all variables and software modules with appropriate headings.

n) Construct a carefully designed, well thought-through visual simulation of this process. Use carefully chosen screenshots to provide enough evidence for the marker, to believe that your automation functions as it should.

o) Do you foresee any technical reasons, apart from your personal preferences, why you should not go ahead with this project? List those reasons if any.

Attachment:- Assignment File.rar