Counting the same part over& over

Hello again
I could use a little help(or a lot depending on who you ask)
I have a rotary filler with 72 valves each valve has a vent tube.I am trying to figure out the best way to count this vent tube every rotation of the filler to make sure it is still there.
I would like to use a captive sensor for detection.

Would just a counter coupled with a timer work?

Say that if the counter does not count 72 pieces within a certain amount of time (slowest time for 1 revolution) send a single to stop the filler.This would also need to be reset every time the filler stops.

Or do I need to have an encoder hooked up for this to get a accurate count every time.

Before I try to do this I want to make sure I am on the right path.

Any and all suggestion will be appreciated
I will be using the ClicK PLC or A SLC 500

If possible I would use two sensors. One would trigger for each filler with the other being positioned to detect the vent tube. I the filler sensor turns on and the vent tube detector is not on then there is a problem. That way you would know fairly quickly.

I have a rotary filler with 72 valves each valve has a vent tube.I am trying to figure out the best way to count this vent tube every rotation of the filler to make sure it is still there.

Click to expand...

A quick dumb question: Are the 72 valves with vent tubes part of the rotary filler mechanism (my assumption), or on the other hand is the product handled by the rotary filler?

If the valves and vent tubes are mounted on the rotary filler, why would there be some vent tubes missing?

+1 for Bernie's suggestion. I'm a believer in positive proof whenever possible and using two sensors, both of which must sense "part-present" for your "good" condition, is just that. One other thing I would add is verification that both sensors are not sensing as the filler rotates between positions. This validates that the sensors are not blocked and that you can trust everything up to, but not necessarily including, your last "part-present" detection.

Steve

Lancie1
Yes the parts are mounted to the filler. The vent tube is within the filling valve. The reason the tubes get dislodged is the operators are too lazy to walk around to the back of the machine and clear the bottle jam. They would rather poke at from the front until it comes free. And in doing so the seal between the vent tube and the filling valve is compromised .When the filler makes another rotation and a new bottle is in the vale with the now improperly seated vent tube the pressure from the filling process blows the vent tube from its seat and into the bottle. AND THIS IS A BIG PROBLEM. It takes a long time to go through each and every bottle until you find the vent tube. I thought about getting rid of the lazy employees, and then I realized I would be the only one left.

bernie
The 2 sensor set up makes sense (he he)
I will try to get this to work using Steves advice also making sure no other detections are happing except for what I want detected.

Bring them both into PLC inputs to Timer instructions, and trap the duration and overlap time of each during normal operation. You may then reduce the debounce time very tight for quick response and set fault timers with a very little bit of leeway for I/O timing variations and expected acceptable wear..

I would also work on bottle jam issue this is the root cause of your problem! No bottle jams no vent tube issues! I would also put in sensors for backup. You could also incoperate an air blast at bottle jam area....solenoid with pushbutton then compressed air fires to dislodge jam....depending on how you are conveying bottles to filler, lets say you are using blowers to convey bottles you could icrease blower speed then decrease blower speed to free jam automatically via logic. The more you can take it of operator hands the better.

This is what I have so far.
Does it look like it should work.
Thanks for any input

vf816,

Try this.

Vaughn, your missing-tube detector is clever and original, and should solve the problem.

milldrone
Thanks for the help.I dont quite understand it at first glance.I will look at it more to see what you are doing.I am not that good at programming yet still learning.(slowly)
PS Thanks for your help on my last problem you and bernie saved the day.
Did my attempt look like it could work?