[OH3] Displaying duty cycle of Fan


in OH2 i displayed the status of a simple switch of a fan, so i can see the switching times and the duty cycle of the fan of a solar heating panel.

After the migration to OH3, the diagram is not working any more.

In OH2 i’ve recorded the states of the blower motor with influxdb and the parameter

strategy everyChange

and the diagram with

Chart item=Solarheizung icon=“temperature” period=4h legend=true visibility=[DiagrammZeitraum==0]

With OH3, i only get a line:

Thanks for your help!


Your Chart sitemap widget is not targeted to influxdb, it’s using whatever default persistence you may have set. (OH3 starts with default rrd4j)

But why is the diagram above working any more? The only difference is, that i selected a group of measurments:

Chart item=gMesswerteTemp icon=“temperature” period=4h legend=true visibility=[DiagrammZeitraum==0]

Under persistence is only influxdb activ:

If you have installed and configured influxDB and did set influxDB as default persistence it should show the persisted values. Having only a single persistence migth not set the default!


thanks a lot for your answer. After a lot of reading, i think i understand persistence in OH3 a litte bit better.

But there remains one thing: Why is the graph not working any more? As i understood, rrd4j stores by default the state of my item Solarheizung, but the ON-State is not displayed (See image above).


Another question: I’ve installed influxdb+Grafana with the openhabian-config tool.

As i understand, this sets influxdb as a the default persistence. Is this correct?


I don’t see why it should. Have you looked to see what your default is actually set to? It’s a user configurable system setting, but I’m not sure where you find it in MainUI.

You don’t have to rely on the default, you can tell your sitemap Chart widget which service to use.

Chart item=Solarheizung icon=“temperature” period=4h legend=true service="influxdb" visibility=[DiagrammZeitraum==0]

Where can i set the default persistence?

What i’ve done: I’ve removed influxdb via apt -> The graphs disappears and in the log are errors, that there are not values. After installing influxdb again, the diagrams are displayed. This brings me to the conclusion, that the data from influxdb is used.

This doesn’t change anything: There is only a zero line, but the item changed in this persiod several times from on to off.

1 Like

On MainUI Settings, second column Persistence.

Did you even try to install the influxDB via the Settings? Without that you won’t be able to belegt influxDB as a default.

As i already thougt, influxdb is the default persistence:

I’ve checked the values in influxdb:

select * from Solarheizung where time >= now() - 1d
name: Solarheizung
time item value

1611130190763000000 Solarheizung 1
1611130550754000000 Solarheizung 0
1611130910738000000 Solarheizung 1
1611131270735000000 Solarheizung 0
1611131630723000000 Solarheizung 1
1611154490987000000 Solarheizung 0
1611154846222000000 Solarheizung 1
1611155150871000000 Solarheizung 0

For my point of view, everything looks good…

Quite a long time ago… but i was not able, to get the graph working. Any hints, where the failure could be?