So, I am a sophomore in high school and know nearly nothing about PLCs. The system goes like this (this is how far I've gotten). You push start. Cylinder #1 fires. Sensor #1 reads cylinder #1 and activates timer (5 sec). After timer ends, cylinder #2 fires. Another timer begins and resets the cylinders. I need to figure out what i could do on a ladder logic program to loop it to start all over again. I know very little about this so if you could be as simple as possible it would be greatly appreciated. Thank you.

 

With ladder logic if the sequence starts when you hit start, it will start when you hit start again.

That's as much of your homework as I will help with.

Regards
cww

 

This problem can be tackled in a number of ways. Which way is best is a matter of opinion/taste.

To clarify:
1) button pressed
2) cylinder 1 extends
3) x time later, cylinder 2 extends
4) x time later, both cylinders retract
5) wait for start button (or did you want it to resume at step 2?)

Any PLC worthy of the name will have timer instructions. If you look at the language reference for your platform, you can get a feel for how they work. Tinker with them some in a simulator (or a spare PLC if you have access to one).

Check out Ron Beaufort:
http://ronbeaufort.com/boot_camp_experience.htm

He has some sample videos posted that are very helpful, especially for beginners:
http://ronbeaufort.com/sample_lessons.htm

Once you get something, try posting it so others can rip it apart (erm, I mean, offer kind, constructive suggestions...).

 

Yes, I have #1-4 down, all i need is to get it to keep going. Thank you, and if you have any more advice about how to program ladder logic feel free to post, i will go to those links now.