Rslogix 500 programming help

Hi guys ,
I know there is so many was to program plc, I'm after the best way to stop an output double triggering,
I was working on a machine last night which I could not get my head around, the application
Is there is a product sensor which is triggering an output but if the product is not in line we get a double trigger I have put a timer in to try and control the trigger it worked better but still get a double trigger, the only way I can see is if I put a hold on circuit and a timer resets it any ideas that could help me , I'm not thinking straight guys thanks stu

Use an ONS before the output
check your help menu for a description

I thought that but osr and ons are greyed out ?

If the sensor and output go ON, OFF, then ON again, then a one-shot BY ITSELF will not solve the problem.

I think that you need tio use a timer to seal-in a clone relay for the maximum length of time that the sensor could see the SAME product. Then use the clone relay to trigger a one shot relay. Then use the one-shot relay to start the output, and a second timer to stop the output.

Testing it with the LogixPro simulator, I turned the I:1/0 sensor on/off 3 times, but the output only came on 1 time for 0.5 seconds. If you want to minimize the program, you can delete the clone relay and simply use T4:0/TT as the trigger for the one-shot.

PS: ONS is only good for MicroLogix PLCs, and OSR must not have anything between it and the output (no instructions or branches immediately before the output).

Import these 3 rungs into your RSLogix program and change the addresses to match your sensor input and product output.

If you XIC your photosensor input to enable a TOF timer, then on the next rung you can use the Timer.DN bit to enable your output.

thanks guys , i will give it a go , thanks again, stu

I think the logic has to depend on how long your output needs to be ON. If your output is to trigger a counter, then 1 scan cycle will be enough. On the other hand, if your output is being used to kick the product out of the machine with a solenoid, then it might need to be on 1/2 second, where your Input might need to be locked in for 1 to 3 seconds, depending on speed of the machine.