PLC Programming

Iainkw4x

Hi I'm a Mechanical Engineering student looking for help with a project. I need to program a Festo PC30 module for a training rig.

The operation is:

PB pressed,
arm goes down,
claw closes,
arm goes up,
jib moves left,
arm goes down,
claw opens,
arm goes up,
jib moves right.

Any help would be most appreciated.

Into The Blue

Iainkw4x wrote: »

Hi I'm a Mechanical Engineering student looking for help with a project. I need to program a Festo PC30 module for a training rig.

The operation is:

PB pressed,
arm goes down,
claw closes,
arm goes up,
jib moves left,
arm goes down,
claw opens,
arm goes up,
jib moves right.

Any help would be most appreciated.

Where are you stuck?

Iainkw4x

I think the operation goes B+C+B-A+B+C-B-A-

but my lecturer told me you cant have the same output in the program twice so I was wondering how do I write a program then?

DublinDilbert

Iainkw4x wrote: »

I think the operation goes B+C+B-A+B+C-B-A-

but my lecturer told me you cant have the same output in the program twice so I was wondering how do I write a program then?

Your instructor is correct, you don't want to turn on an output at multiple points in the program.

Do you have limit switch inputs to detect the various cylinder positions? or do you have to use timers?

I assume your using ladder? What PLC type?

There's a couple of ways to program this, in my opinion you should use state based programming. You use internal relays to track what state the system is in. Your sequence itself has 8 states, possibly 9 if you've to wait for a start button to be pressed.

If you look up state based programming in Kevin Collins book:- http://runplc.com/wp-content/uploads/Books/plcprogramming.pdf

This will tell you how to write a state based program in ladder.