A little help in programing or same ideas whould be useful. S5

Hy , so here is my problem.

I what to make a program for a S5 100U PLC, the application consist in rejecting, lets say a blue cube, from a conveyor belt.
I was thinking as follow : the sensor sees the blue cube, a input is made in PLC, which activate a timer (i use a timer because the speed of the conveyor belt is constant and the distance between the conveyor belt and the sensor is 'x' (dose not mater)), and after same time which is equal to the distance travel the blue cube is rejected.
My problem is: if more blue cubes passes the sensor before the firs one is rejected, i think the program will not keep count of first ones, except the last one.

Has anyone any idea to how i should solve this problem.

My experience whit Step 5 is a entry-level .

Thanks in advance for any idea u give me.

My idea for you is to hire someone with experience in this type of control system. Work with this person to learn.

I want to do it myself if possible. I haven't ask for someone to solve my entire program, i wanted just a idea, a 'road' to follow. After hours of searching, someone suggested to use : FIFO buffer (first in first out).

you can use counters, comparators and timers to solve this.
If the counter is 0 when you get the signal enable the first timer, then if a second one passes befor the timer has run out you count up the counter with one and start another timer and when the timer has run out you simply decrease the counter with one and so on.

Hi

So i have partially solve my problem, the solution i have come up whit are :

1. The first one was to move the pusher beside the sensor, so i had to use only a timer ( a easy solution )

2. For the next one, i kept the distance 'x' between the sensor and the pusher, and the speed of the conveyor line constant ( v = ct ), I use counter's, comparators, and timer's, below is an example of the program, i use step 7 because it's easy to use especially the simulator.

3. The 3 one is the hardest for me, because i want to kept count of the line speed, so i have anther input that keep count of the conveyor. To be honest i am stuck, because i don't know what to use, i solve the problem whit multiple cube's that pas the sensor , but don't know how to implement the counter that keep track of the speed

If anyone has same ideas, i will gladly listen

P.S. Thanks ojz0r, for the idea.