create a bottle count

hi there to all.new to the forum enjoy reading some of the threads.i have a filler using a micro board so i have no acess to changing controlls.it uses an infeed sensor to start the whole control.this input must be high for more than 2 seconds in order for the head to dive.the problem i have is if there is a false trigger or bottle stuck in front of the sensor the systems see it as all okay although no bottles at filling head,thus product drops to ground.my solution was to take the input to external plc ,then do a count function which inturn would be the input of the board.problem is that after each complete count i am reseting the input to the board which has a negative effect on the throughput of the machine.how can i with sensors start a count and if not completing count in this case 6 bottles to interupt the controls.all inputs to the board is N/O

I guess that this is a filler with the bottles entering in a line. Six bottles normally move under six filler tubes. A sensor is upstream a couple of bottles back from the ones which are in the filler. When it sees that the row of bottles has stopped moving (I assume it turns off between bottles as they pass in front) it then begins the filling process.

You want to place a similar sensor on the output of the machine so that the six filled bottles which are exiting the machine make it in a similar fashion. When six have been seen then you will allow the upstream sensor to send its signal to the micro board.

Assuming that the upstream eye circuitry is not doing a count of its own (which it probably isn't if it allows filling when the bottles have not moved) then this should work. You will need to monitor the signal which releases the bottles. The beginning of it would be a reset. When six transitions have been seen then the output, which probably should go to a relay unless the PLC has isolated relay outputs, will turn on. It would then wait for the release signal to transition on again.

What small PLC do you have in mind? It would only need two inputs and one output. Or do you have spare capability in a nearby controller?

bradlet said:

i have a filler using a micro board so i have no acess to changing controlls.it uses an infeed sensor to start the whole control.this input must be high for more than 2 seconds in order for the head to dive.the problem i have is if there is a false trigger or bottle stuck in front of the sensor the systems see it as all okay although no bottles at filling head,thus product drops to ground.my solution was to take the input to external plc ,then do a count function which inturn would be the input of the board.problem is that after each complete count i am reseting the input to the board which has a negative effect on the throughput of the machine.how can i with sensors start a count and if not completing count in this case 6 bottles to interupt the controls.all inputs to the board is N/O

Click to expand...

Because of the negative impact problem I would try this.

Leave the original input to the machine unaltered (unless this is how you reset it). Instead monitor and interrupt the outputs. Install some interposing relay contacts in between the machine outputs and the actuators. If you sense a problem with your own sensors and the machine starts to fill, interrupt the interposing relays, reset the machine, and do what ever you need to do (alert the operator, stop conveyor, ect.).

thanks
i went with the option of intervention