PLC Assignment!!! Please HELP!!!

Hi all...

I have a PLC assignment for my instrumentation class and I'm unsure of a couple questions. If anyone can email some help, that would be greatly appreciated.

QUESTIONS
1. Explain the difference between forcing an input and forcing an output.

2. Explain the basic scan cycle for a PLC and what happens in each phase of the scan cycle.

3. For a basic starter configured to meet industrial standards, explain the sequence events that occur when the start pushbutton is pushed. Include the impact on the scan cycle.

Thanks all!!

Hey there.
The answers to most of your questions are at the top of this forum in the TUTORIALS tab. Please read that and come back with any questions that you don't understand. There is a lot of good info right there.
Regards
Craig

1. ones an input and ones an output

2. It varies from brand to brand

3. I'd use a seperate starter for more robust current handling.

You ought to remove your email address from your post -- spammers actively scan forums such as this for openly posted addresses to spam.

That is, unless you really, really like getting spam email.


Then, do your own homework. I'm sure the answers you're seeking are in the book that you were supposed to read for the class. Either that or the material was covered in the lecture. Usually homework doesn't cover material that hasn't already been presented.