Output only once when over threshold

[cairon]

Hi there,

I have a I think simple question but I am not getting it.

I want to build a ventilate alert, so I want that Node-Red send ONE (!) message if a value is over a given value.

So "Send me a message if value A is over 200 and keep quiet till it is under 200 and then over 200 again"

Can you help here?

Greets
Daniel

[E1cid]

You can set a boolean depending if value is over 200 and then use a filter node to watch the boolean.
e.g.

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