Hello Lukas, the idea that the whole thing no longer works when the power is switched off is of course correct. But you would have the same problem with a LoraWan solution. In order for the “alarm” to go off promptly, you would have to use a Class C solution, which is usually not a battery solution. But if you use a Class A solution, your “visit” may have gone by the time the node reports again and the subsequent downlink turns on your siren. BTW I think it’s a very bad idea to plan “siren ON” and “siren OFF” as 2 commands, if for whatever reason the 2nd command to turn off doesn’t come on, it can cause real trouble. If so, you should provide it with an automatic switch-off (called PulseTime by Tasmota).