project help

[dimitrs 0]

hello everyone i am a student and i have a project to make using plc from siemens....the code isnt the problem,what i lack is experience in real projects for example i wanna run the plc in a transporting tape which categorize the products by height and sends them left or right...its pretty simple but since i lack the experience of the real think i dont know what parameters should i use...for what should i use alarm...what should i make sure not to happen...that kind of stuff...i dont know if i managed to get you the picture..i hope i did and u guys should help a bit understanding those things...thx in advance :D

[kaiser_will 65]

For new controls guys, I suggest flowcharting your application.  A well thought out flowchart can be turned into working code in no time.

All of your questions are encompassed in a good flowchart.

The next suggestion, state machine.  A programming approach that many companies have gone towards is state machine.  Your ladder logic program has a state for every step.

The last suggestion,  it is hard to get other people to do your homework assignment for you.  If you fine tune your questions to specific detail, then you may have luck obtaining the proper response.  Screenshots and spelling out exactly where you are stuck is needed.  Otherwise you are expressing vague generalities.  Engineers do not function in vague generalities.

[dimitrs 0]

well i never asked you to make this project for me....even if you did i wouldnt take it what the point in it what i have to gain? only a grade? to do it what? picture on the wall? i wanna learn...but to learn i need resources and practical education which i lack atm and its not only my fault...anyway here is where i am so far in the project...if u have time read it...i guess u will see there what i truly was trying to ask help for 

S1 : sensor that tell us that cargo is on the thansporting tape and starts it

S2:  when its 1 tells us that cargo is short
S3: when both s2-s3 1 tells us that cargo is high

S4 : when its 1 tells us that cargo is  near the peristrofic transporting tape and so it starts it.

S5 : its the peristrofic transporting tape. it has a little button in the end of it i dont know if u see it but when its 1 depending on the 1 of S2 or S2-S3 moves the cargo to the right or left and starts moving the other way pushing cargo of it.
S6 : when its 1 means that cargo went through so peristrofic transporting tape goes back to its 0 position
S7 : same as S6 (remember cargos can go depending on high left or right)

Q1 : when something goes wrong (which is what i need help for in the 1st place) this motor runs so it can shut down the tapes while it can

The theoritic part or else the "problem" is this :
lets say we have a factory that produces cigarette's and we put them in boxes so we can transport them. we split the categorize of boxes in high and shorts ones depending on how many packet of cigarettes we wanna put it for shipping. we have already secure that boxes go in the transporting tape (near S1) every 15 sec. if the box is high (S2+S3) put the box left (towards S6) if the box is short put it right (towards S7).  if 15sec pass and S1 activates but S6 or S7 havent been activated yet means that cargo stuck somewhere so activate Q1.

thats all i though so far and what i want from you is just give me idea of what might go wrong....so that i could cover almost all the things that would happen....i have some more thought for example if the cargo isn shorter that S2's reach...or it isnt heavy enough to activate S5.... but i havent figure out how to use the 1 and 0 on the other yet so i can work those occasions. so thats what i really wanna ask from you guys...ideas of what could go wrong in a transporting tape. thx :D