Hi.

I have a flowmeter with puls output, abt 930 pulses per liter.

I have managed to arrange the total volyme, with counter and it´s quite simple, but i also want the momentary flow every minute.

And there I have a slight problem because the momentary flow or rate needs to be "erased or updated" otherwise the momentary flow will not change so much when time have passed on to long.

Im using a mathematic instruction and a timer, but sometimes when it resets, the mathematic instruction calculate it as a overflow because there´s no values yet. 

The counter is set to 1 with 10 pulses, easier during simulation.

Does someone have a solution on this one? 

ixo65

Here is a possible solution.

She works to 30473 pulses per minute, or about 507 Hz.

A small note..
The text in the code refers to making a sample every 10 seconds, but the code (threshold trigger & math instruction) makes sampling every 1s. Personally I would go for the idea of sampling every 10 seconds.

The flowmeters output is 930 pulses per liter, but maybe i will change it to 4500pulses per liter (you could insert a cone to the flowmeter to change the values and make it more sensibel)

The application is for a petrol Engine in a boat so the flow may vary, from 3 l/h to maybe 140 l/h

Thank you ixo65, hopefully I will try it this weekend :-D 

And then i will use a counter for the total volyme.

Why didnt i thought of a threshold trigger...

Almost forgot, its a logo 8 with fast input, 12/24v :-D 

Hi and thanks for the program! 

One question that came up when testing the program. When I simulate at 175Hz I would expect to get 140 l/h, but the program shows 139,8 l/h. Would I get the same result with a flow meter or only in simulation mode? whats the reason for it and is there a way to go around it? 

BR