Problem summing value of number item


I have a problem with one of my items. I have an item of type Number. One an hour i set a double value to this number item using the sendCommand in a rule.

So the item should have 1 double value per hour. I use a rrd4j persistence and I am well aware that the level of detail is reduced over time. Still, I don’t think this should be an issue here.

What I try to do is to sum the values of the last day by doing:
myItem.sumSince(now().minusDays(1), “rrd4j”)

I also log the individual values per hour and the result should be something around 35 but I get a value of 1390…

Does anyone have an idea what is going on here?

rrd4m must be used with the strategy everyMinute, no option to get around this point.
If you change the strategy, rrd4j will stop working.
You could of course set the item to the value and set it to 0 after a minute, but that’s not correct.