----- Original Message ----- From: "stefan" <stefan.bru...@gmx.net> To: <rrd-users@lists.oetiker.ch> Sent: Friday, July 05, 2013 9:31 AM Subject: Re: [rrd-users] how to calculate the sum of a DS
> Hi Alex, > thank you for your explanation, but now I am little more confused. > my PV controller gives me the power created ( example 400Watt) each 10 > seconds, > so I have 400W/10s. No. It's not 40W every second. It's 400 (on average) Joules every second during 10 seconds. That is: if your device indeed does report in Watt. Also possible (and more likely) is that your device reports energy delivered, for instance in Wh. If you confuse W with Wh, you won't get correct numbers unless by chance. Make sure you understand the difference, and why it is watt multiplied by hour, not divided by hour. > For my understanding I should take the sum of all value (where watt >0) Why the ">0" restriction? We'll get to the rest as soon as you figured out exactly what is reported: energy or power. _______________________________________________ rrd-users mailing list rrd-users@lists.oetiker.ch https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
