Board Pusher

hello there,
i am facing some programming problem in one of my system.

logic is:

in a roller conveyor there is a limit switch in the middle. so the system should work like- the roller is altime on but when a board is touching the limit the roller will stop and after stopping 2 pusher ( solenoid valve) will push the board to be allign with the conveyor and solenoid will retract it self and roller will start again.

i should mention that i have used NO type limit switch and board will be touching the limit switch all the time because boards very close. so i have used one shot for the limit switch so it will turn on one time with each borad touching it. after that i cant make the cycle to start the conveyor.

any type suggestions is welcome

I'm not sure I understand the question. Does your pusher cycle work properly? If so, then simply disable the conveyor whenever the pusher is cycling.

|      PUSHER                 CONVEYOR

|     IN CYCLE                  RUN

|-------]/[---------------------( )

The conveyor runs when the pusher is NOT in cycle.



-Eric

i know that,,,the way i did


power limit motor
-----/ /------/\/------------0----

so when the limit is off the motor is running. but when the touches the limit it becomes NC and then the motor should stop and at the same time 2 valves activates itself for 1 cycle. and after perform 1 cycle the motor will run again even though the limit is still NC position.

until it gets another board the motor will run..

i hope this might help you.

Hi,

Im not sure if I get the correct picture of what you mean, but the way I understand it you are having problem during the time your 2 pusher is ON then OFF again and the roller restarts to run even when the Limit switch is still active (board still touches the switch). I hope I get it right. By the way, I think you can use the reed/ proximity switch of your pusher (if it has) to inform your system that it has extended & retracted and the roller is okay to run even with an active limit switch on the conveyor. OR you can use a timer & use its contact to inform your system that the pusher has finished & so the roller should run even with an active limit switch.

I think its hard just just create 1 line condition when you want to make exemption.

Hi,

I have attached my program regarding your querry using two reed switches, 1 @ retracted position & the other 1 @ extended position. I hope this could be of help.

Anyway, you can replace the switches with a timer if your cylinder dont have switches.

I hope I get you right.

yes you got the idea...

i have used a timer in my part....

but i am afraid that the pusher will be 'on' all the time ...

stuck...

i have modified it...
please let me know...
thanks

Oh well, in that case I edited my diagram (please see attachment).. I only use 1-shot of the timer T0's contact. I hope this is of any help.

The timer that I use is an ON-delay timer, with time 5s.

what is M1.. i can guess M0 is a bit...nice job though