Slc program question

[BOB 0]

Can't figure out how to write  code  for conveyor system.3 conveyors.Tried timers but wouldn't work because parts vary in length.I need to  probably latch each conveyor on and off and reset when full????? Part is placed on conveyor A,It turns on B ,part goes to B it turns on C.Part stops conveyor C at the end by a photo- eye.Next part advances to B and is goes to the to the end of B and photo -eye stops conveyor B.Next part is placed on conveyor A and stops conveyor A by another photo-eye. Conveyor system is now full .At this time an output will halt part placement until a part is removed from conveyor C and the process begins again. Used blocked /clear with timers on each end photo eye and it now works!!!!!!!!!!!           Thanks

[Chris Elston 78]

Can you upload the RSS file to this board? There is an ATTACHMENT feature just above the reply button. Thanks Chris

[Guest Peter Nachtwey]

This is not a SLC question, it is an application question.  I recommend using an encoder so you can keep track of exactly how long and where each part is.

[Guest Steve]

This sounds like a pretty simple application.  I am assuming that each conveyor section has a photoeye at the end of it to detect if a part is at the end of a particular section.   You said that the parts vary in length.  By how much?  Can a part block two eyes at once?  If parts only vary in length a little, I don't see the issue with length.   If I continue to assume that each section has a photoeye, when a part is placed on A, conveyor B turns on and then conveyor A shoudl turn on after B is on.  When the part moves to the eye at the end of section B, then conveyor C should turn on, and A can be turned off (provided no new part has been added).  When the part reaches the end of C, then all sections can be turned off, provided no new parts have been added. I would like to see a simple sketch of layout of the conveyor sections with something on the length of these parts.   I would approach the programming of this by looking at the three conveyor sections as independent stations.  Each section accepts parts and sends out parts.  I have written many conveyor programs.