Buenos días, JCFERNANDEZ74!

I'm sorry but I didn't quite undertand you. Can you be clearer, pease?

The best way to program some math is in SCL. 

Dear Stalincode,

My question is whether it is necessary to use a fast counter for the speed of 25 Hz that I need. I don't think so, but I'd like to ask for your opinion. Then, to calculate the liters per hour based on 1000 pulses per liter and do it in KOP, what would be the fastest way?

Best regards

25hz means 40ms. I think that its not too fast for the PLC, but it depens on your scan time.

If you are programming with Tia Portal, you can introduce SCL rungs in your LAD function or you can also do it with LAD, because it seems to be an easy application, but first of all, you have to know how the external counter works: It's important to know whet you have to start counting and when you have to finish counting. After that, we can make the logic.

Best regards

If you want to use HSC, I've found this topic:

Topic

https://support.industry.siemens.com/forum/es/en/posts/frequency-metering-s7-1200/111353

If you want to make it coded, may be this draft works:

Have a good weekend!

PS: You need an alarm if the value counts is over 80.000 (80 liters) and maybe the 500ms should be changed for 100 ms. You'll need to add a counter reset too.

Thanks a lot for your help Stalincode, I will try this example.

Best regards