Effectivement, ce n’est pas trigger mais events qu’il faut utiliser.
Comme ça, ça doit marcher:
[{"id":"a3cf98ae.3a9028","type":"debug","z":"e65df6a0.5d2a98","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"data.new_state.attributes.timestamp","targetType":"msg","statusVal":"","statusType":"auto","x":640,"y":1520,"wires":[]},{"id":"a3a706c7.c43878","type":"server-state-changed","z":"e65df6a0.5d2a98","name":"","server":"d28c9492.f419c8","version":1,"exposeToHomeAssistant":false,"haConfig":[{"property":"name","value":""},{"property":"icon","value":""}],"entityidfilter":"input_datetime.test","entityidfiltertype":"exact","outputinitially":false,"state_type":"str","haltifstate":"unavailable","halt_if_type":"str","halt_if_compare":"is_not","outputs":2,"output_only_on_state_change":true,"for":0,"forType":"num","forUnits":"minutes","ignorePrevStateNull":false,"ignorePrevStateUnknown":false,"ignorePrevStateUnavailable":false,"ignoreCurrentStateUnknown":false,"ignoreCurrentStateUnavailable":false,"x":280,"y":1520,"wires":[["a3cf98ae.3a9028"],[]]},{"id":"d28c9492.f419c8","type":"server","name":"hassio","legacy":false,"addon":false,"rejectUnauthorizedCerts":false,"ha_boolean":"y|yes|true|on|home|open","connectionDelay":true,"cacheJson":true}]
Je ne sais pas ce que le noeud KNX veut en entrée… Mais, j’imagine que le timestamp sera plus facile à manipuler. Le debug montre comment y accéder.