[SOLVED] Graph in Habpanel should show a line if no additional values beeing added

I’m trying to show the state of a switch (a heating valve) in a graph on second axis.
The temperature changes every few minutes and will be plotted continiously. But the valve state (Num 0/1) is shown only on state changing.
So if there’s more time passed by as the graph is showing (ex. 1h) I’ll miss the information about the state.
I’s there a way to keep the last value shown as a horizontal line in the graph?

I’m using InfluDB as backend, n3-line-Chart with “live update” and the second optoin “falls notwendig aktueller Wert anderer Serie bei Update fortschreiben”.
System openhab 2.4 on debian 9 / raspi 3.

Yes, you will need to persist the valve more often, maybe every 5 minutes should be sufficient
Add a 5 minutes strategy to your persistence
and add this strategy to your valve item

Thanks for this workaround.
I thought there was another way to get this solved.