Help needed

hi guys, a total noob at plc who is in need of some homework at school.

So the way we look at homework here is that the help you get is directly proportional to the effort that you show when you present your need. Posting your assignment without showing what you have done so far on your assignment will get your nothing (except maybe a few comments like this)

Make an attempt at your assignment. Show your work. Ask specific questions where you need clarification or don’t understand a concept and you will get help.

The assignment was distributed more than a month ago and is due tomorrow. You have had plenty of time to get working on it. What have you done so far? Please don't tell us you're just starting now.

At least the instructor got it right.... :site:

Sources of information to
support you with this
Assignment

www.PLCs.net - Online PLC Tutor

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geniusintraining said:

At least the instructor got it right.... :site:

Click to expand...

This homework is so unrealistic, manager/bosses ask you to review PLCs... *you go and learn all of this info get pros/cons and set to go*.

Manager/bosses already make decision based on whatever sales pitch makes them feel warm and comfy. (My current life, nobody on-site has any experience with a new system they installed.)

www.PLCs.net - Online PLC Tutor

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Hang on until I find the pre-prepared instant solution from the database....oops!

Best of luck in finishing your assignment for tomorrow...

This assignment looks incredibly useful as a introduction to PLC hardware and functionality.
Also the kind of assignment I would loathe in my school days and perhaps leave unfinished.

The good news is, I'm soon to be starting as a plc lecturer at a local college.
That will be the end of unitary and modular.

After teaching for many years this question is a time waster.
This would be a great exercise after they have programmed disparate PLCs.

Sounds like a terrible assignment.

Typically vague question on a BTEC… not moved on much from when I did my HNC. I do recommend that W.Bolton book though, it was useful when I was at college, and it’ll have all the buzzwords they’ll be looking for in it.

It says they want to upgrade their existing control system, but then doesn’t give any indication as to what that might currently be.

The lecturer will no doubt be following this thread - Hi there!

I doubt there are any marks associated with the actual process description, it’ll be all based on PLC knowledge, so I don’t see any harm in some basic info on pumping etc. On this course it’s unlikely the students can even visualise a water treatment application

For the pumping one: You would expect a pair of pumps that pump out of a tank which is constantly filling up with waste water - when the level gets high a pump is switched on and pumps it down into a sewer or maybe another tank. So in its simplest form you’d have a high level switch and a low level switch to stop and start the pump. Some systems run with an analogue 4-20mA signal from an ultrasonic level - so you might want to think about how that might be better than simple switches, and what you might be able to do with the analogue signal in the PLC? Notice also mentioned there are two pumps usually - so the second one is used for if the first one fails. Think about how that might be controlled by a PLC. This is often called a duty/standby arrangement - but sometimes they are configured as a duty/assist pair - so think about what that might be about and how might you control that kind of setup

So the above isn’t an answer for your assignment, you just need to understand that that’s what you’re probably controlling. Start off discussing how you’d control it in its simplest form, and then run onto how you could improve it with extra functionality. Choose a couple of manufacturers from the big 4 in the uk and compare parts (Schneider, Mitsubishi, Rockwell or Siemens)

I could have easily answered your actual question, but as others have said - you wouldn’t learn anything that way…

Andy