Nice way to track pallets on a conveyer?

[PeterW]

My few conveyors is building up.. PeterW Ill take your suggestion and use a internal pulse..

Is this how you usually do it?

(if motor running xxseconds then pulse cnt down section a)??

Virtually all my work is about tracking objects on conveyors, usually with a lot of information with them and with the restriction that items can never be confused.

It depends on what you need, if its just counting how many items then it can be simpler.

You need to ensure that the photo eye cannot 'see through' the pallet, so at all time when a pallet is passing the sensor is blocked.

Then you need to just track the leading edge of the pallet, which means a one shot when the pallet reaches the sensor.

The tracking can be done with single bits in registers or by moving registers, if there's no information being tracked then it can just be '1' = pallet, 'o' = no pallet.

Each 'bit' or 'register' move can be equal to a distance, if the conveyor moves 5 inches per second and the pulse is every 200mS then each pulse = 1 inch, so each movement in your model could be 1 inch.

You'd need to be able to detect the pallet if arrives slightly early or slightly late.

When a pallet is detected at the first photoeye, you can increment a count, when a pallet leaves the last photoeye you decrement a count.

The photoeyes in between, if an unexpected one appears then add one, if an expected one does not appear then subtract one.

You could do this type of counting on each conveyor is required.

If bits, then use Bit shift type instructions if using registers, use table move type instructions.

Only shift items in you model if your conveyor is running.

 

[bara_hence]

PeterW thats a really nice soulution.. The problem for me is that I dont have the data (speeds, etc,etc) and will not have until the machine is supposed to be running and I think ill be making a hen of a feather or how you say it...

The problem for me is that i want to make a nice soulution for them but maybe im just overworking an easy conveyer..

Some more info about the conveyer

The function for the conveyer is just to transport magasines with molds first to the mold insertion then to the mold removal station.. And the conveyor has some features to take into consideration - For example in the first conveyor there can physically be i think 5 magasines and I have three photoeyes.. In the end the conveyer shifts direction and gets carried away by another conveyor section the soulution for this is that the chaindrive is lifted until a magasine reaches the station for shift direction when it gets there the drive is lowered if the other conveyor isnt running.. Then the other conveyer is started and the magasine goes away in the new direction..

While the chaindrive is lowered i can still put new magasines on the infeed conveyer and drive that magasine to the last sensor before the station for direction shift this is for buffering magasines..

Becausse of all this I want to track the magasines sometimes for position and sometimes just for knowing that there is magasines on the conveyer..

All of this could be solved with just timers and maybe I should have taken that direction from the start but now I have already started designing and implementing the functions for this conveyer.. But I really feel like Im doing it overcomplicated the first section with the lift and conveyer and such needed a state diagram to get solved in a nice way but I think that someone more experienced would have solved this both faster and nicer..