Anyone know a good quick small algorithm for plc use to control the spacing of containers along a conveyor line using one photoeye and one clutch brake relay.

Pitch control (leading edge/leading edge) four seconds apart.

 

if the spacing is not critical, you can pull a distance between containers by switching to a faster conveyor. Are these filled containers? can you catch them as they leave the filler? they will almost certainly be spaced then.

 

I assume you are dropping the box on a stopped conveyer breaking the photocell beam which then runs the conveyer untill there is space for the next box. Have the breaking beam trigger a delay off tiner through a one shot. As soon as the beam breaks the timer done bit will be enabled and turn off after T. The done bit runs the conveyer.
Simple but it will work if the spacing is not critical.

 

Seems to me like a recipe for destroying the conveyor clutch brake assembly to me if it is used frequently.

Bob Peterson

 

I have a similiar application where spacing is even more critical and am unsucessful finding any feeback. I require a constant distance between packages that arrive via an uncontrolled conveyor. Packages arrive at 403 FPM and i have 3 8 foot longservo controlled conveyors to pull a gap and space them at a 10" gap. This can require speeding up and slowing down of the 3 conveyors. I have encoders as well as photo eyes that i can install. The problem is the formula or calculation to space a package on a moving conveyor.. Any ideas anybody... I appreciate your help!!

 

Is your problem that you need a box every 10 inches, or that they can be no closer then ten inches?

If the latter you can just speed up the last section relative to the previous section so there is always a gap between boxes as they come off the line. if the boxes are the same size, the gap will be the same, or close to it.

If the former, you need to do some thinking, but I would bet you can come up with something based on the speed of the line and the box size, assuming you know the box size.

The people that sold you the sections must have had something in mind for doing this when they sold you the equipment. Why not ask them?

Bob Peterson