Hello DHouston

Thanks for your support
What i need to do is this:
A machine have a optocopller on one part that everytime this part are moving i have one impuls and this impuls i want to count and increment and send the total value to the PC everytime this impuls appears, and this on all 40 machines.
(I don't have control how mutch times and when the impuls appears).
So, i can show in realtime the total count of every machine on the PC

Yes, i mean the RFM12 from http://www.hoperf.com/pro/rfm12.html, or know you other low cost device?

Do you think that the code of the method of your link can work with this?

Thank you again

Regards
Pedro