Chart node sending output at regular(ish) intervals

Dashboard
1

Although I've been using the chart node for a while, I've never used its output before, but now I want to do some analysis of the data, and also save it for reloading on restarts (it's still very much early development, so there are a lot of those).

When I added a debug node to check what the data looked like, I found the chart was sending outputs at roughly regular intervals of around 60 to 90 seconds. These are shown in the attached debug pane image, which includes an expected output when the chart receives an input message from a temperature sensor.

There doesn't seem to be anything in the documentation which explains this "tick" output, and no settings for the node to adjust, or preferably disable it. If anyone knows how to modify this, I'd be grateful for any ideas.DebugOutput|254x500 .

2

On socket connection event the output is fired. By just standing still I have no output from chart.

3

Ah, thanks for that info. So it looks like my browser connection which is displaying the dashboard is refreshing every so often, which I suppose is to be expected. Closing the tab stops the messages from the chart.

I'm in the process of adapting the ideas in this "Simple save and restore" flow - https://flows.nodered.org/flow/92920b4fd450bf92a3035e061947daa0 - and wondered why there was a check for message topic being NULL. This explains it, and keeping the check will avoid saving the data randomly.

All good to go now - onwards and upwards! :grinning:

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