Thanks for the reply. When you say "goes off", do you mean that it stops working/communicating or that the siren sounds?
This would be a new device. Mainly looking for something for low volume notifications rather than a high volume siren, but the Aeotec seems to have enough options for that purpose. I don't really like the wall wart idea (I think I saw that the previous generation was a plug-in). In general, I'm not finding a lot of alternatives. Ecolink has one and I found a few other knock-offs, but the Aeotec seems to be the most popular.