How to make a constant calculation of the remaining length?

Ok, that's what I thought.

I'll just do the calculation every 30 seconds, to make it as accurate as possible;

Now something else, I need an output if the resting value (Aq 600 in graphic) is less than 1000, how can I do that? Don't find a function to compare that value with a solid value...

Thanks in advance

ixo65

In attachment another suggestion.

Instead the length not in cm but in mm.

Counters works with double integers. So is the start value instead 10,000 cm then 100,000 mm.
By a speed of 1.040 m/min is then the difference 17 mm per second. 

 This looks interesting. I guess this will be more accurate?

Now I have to do this 4 times, on the 4 screens.

Problem is that all 4 circuits should have the same Output (Q1) and same red screen (M31).

I can't use them twice? Normally (in Tia) you can do this with markers and an extra line of programming, but here you can't use markers twice too.

Is there a way?

Thanks in advance

Ok yes, sometimes even forgot the most simple things .

But the program will become kind of a spider web 

We work in mm to work as accurate as possible

For the moment, the operators have to give in the length in mm... Should it be possible that they can give it in in metres; in fact they only can see and adjust the first 3 numbers of our mm value? Because it will be to confusing for them.

+ is there a possibility to change that value not only by hand, but also with a second analog input, like a potentiometer?

Thanks in advance