Carwash project

[upstudent]

This is the first time that I have looked at this site and I thoght that I would give it a try. I have a problem, I'm currently in a PLC's class and my Prof, is not teaching us anything. He just gives us the projects and expects us to figure them out. I not asking for all the answers, But I'm looking for alittle help. So if anyone would like to help me, it would be greatly appriciated. I need to get though this class so I can graduate in December.


I listed my project below.

Thanks for anyones help


UPstudent


Carwash 1
I. Objective
You have the automatic carwash as listed below. Write a PLC program to automate the
carwash. Be sure to thoroughly document your program.

II. Specifications
You have an automatic carwash that has five sections. It has an initial rinse, a wash, a
final rinse, a wax and a dryer section. The car is driven into the car wash until the stop
light comes on.
You have in input (I:1/0) that goes high when the car reaches the appropriate spot. You
also have inputs at the entrance point to each section - initial rinse (I:1/1), wash (I:1/2),
final rinse (I:1/3), wax (I:1/4), dryer (I1/5) and one at the exit (I:1/6). Additionally you
have a master control switch (I:1/11).
Your outputs are a stop light/sign (O:2/0) that tells the driver he is at the proper position.
A wash in use sign (O:2/11) that should be on anytime there is a car in the wash (only one
car at a time is allowed in the wash). The motor (O:2/10) that pulls the car through the
wash. The rinse pump that pumps the rinse water (O:2/1). The rinse valve (O:2/2) the
directs the rinse water to the initial rinse if it is activated or the final rinse if it is not
activated. The wash pump (O:2/3) that pumps water for the wash cycle. The wax pump
(O:2/5) that operates the wax cycle. The dryer motor (O:2/4) that turns on the fan for the
dryer section.
Your job is to develop a fully documented PLC program that will turn on the stop light
when the car is in the proper position and turn on the motor to pull the car through the
wash. Each section should activate only when the car is in that section. The motor of
course has to be on the entire time the car is in the wash to pull the car through and should
turn off when the car exits. Also the wash in use sign should be on the entire time the car
is in the wash. You also need to make sure nothing operates unless the master control
switch is activated.
** Note that each section is longer that any vehicle allowed in the wash - in other words
you cannot have multiple position sensors on at the same time (i.e. I:1/1 and I:1/2). Each
section needs to operate as long as any portion of the vehicle is in that section.

 

[glaverty]

No one is going to give you the answers. Show what you have done and ask specific questions about things you are having problems with. Also do a search on this site for "Car Wash", this has been discussed before.

 

[T-Moulder]

Give it a go!

UpStudent -

I beg to differ - your instructor has given you quite a bit of information. Unless you need help with the absolute basics (Normally-Open / Closed contacts, coils and timers), you've got everything you need here.

I've been doing controls for 10 years now, and have been handed a number of requests with less detailed specs than this

Grab your book, take a shot, and then show us what you come up with. Then we'll be happy to help debug.

TM

 

[jrwb4gbm]

Here's a hint to get you started.
Set up an empty program ladder. Put just the first output you want to control on a rung by itself. Next, put on that rung the first input you need that makes the output change. Test that on your PLC until you get the desired results.
Continue adding inputs that affect that output. Test each additional change using all the on-off combinations of the inputs.

The hardest part of programming is defining what needs to happen and when, the instructor has already defined that.

Good luck.

 

[rsdoran]

http://www.patchn.com/b4programming.htm