Hello, I am an absolute amateur with minimal experience. Could someone help me create a simple program for measuring flow, I can't do the correct conversion of frequency to liters per minute.

Data from the flow meter: Pulse characteristics: 68 Hz (Q – 150 l/min), 34 Hz (Q – 75 l/min), 2 Hz (Q – 5 l/min); F = 0.45 * Q

I'm sorry, but I did it almost the whole weekend and unfortunately I can't do it. I know that for an experienced person it's about a two-minute job.

Please help.

Thank you

The conversion factor of 0.45 is incorrect.
Maximum frequency = 68 Hz
Maximum flow rate = 150 l/min

68 ÷ 150 = 0.4533333333

And the LOGO! can't evaluate frequencies. In addition, the LOGO!'s standard digital inputs don't process 68 Hz. That would only be possible with a LOGO! that has fast counting inputs.

I have this logo with the marking: 6ED1052-1MD08-0BA2

Try this.

Thank you very much, you are really kind. I would probably never have managed to do that calculation.

I would like to ask you one more thing. How did you proceed with that calculation? I would like to have an idea for the next time I come up with something so that I don't have to bother anyone.

Thank you very much.

68 Hz equals 150 l/min.
1 Hz equals (150 l/min ÷ 68).

So:
150 l/min divided by 68 multiplied by the current frequency value.

That's the complete, straightforward formula.

Thanks for the explanation, now I feel like a total *** :-D

Yes, sometimes it's like that...

You can't see the forest for the trees.