How does OpenHab work when my computer is off?

Hi all, I was wondering how OpenHab works when your computer is offline. I am extremely new to the software and haven’t even downloaded it yet. I wanted to do some research before making the leap. I need to create a security system that works even when my computer is turned off. If OpenHab does work with my computer offline, I would also like to ask how does my devices still know how to handle and communicate inputs?

First welcome to your home automation journey.

You can only use openHAB if you computer is running.

I would recommend using a small SBD computer to run openHAB on separately to your main pc. They have a small footprint and don’t consume much power.

I would recommend getting a RPi 4 with 4gig or ram. You can install openHABian on it or many other home automation systems if you decide to go with something else.

Remember that openHAB is a home automation system, not a dedicated security system. It’s not likely to ever have the integrity and failsafe features of purpose made intruder alarms, and so on. Though of course in can work in conjunction with specialist systems.
It all depends what degree of security you have in mind.

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Hello Nicholas,

somehow your question is mixing a few things.

If you computer is turned off, functionality is limited to what is working without OH being present.
Depending on how things are configured you will see ZWave or Zigbee not working anymore, as their coordinators will be turned off as well. You may configure associations between the devices (e.g. room thermostat and thermostat valve or button and lightbulb, but this is very limited. A knx system usually still works to a much wider extend as it is designed to be operable without a central server instance.
What you are definitely losing is interoperability between different technologies and protocols.

If you plan to run it “offline” there are two scenarios:

a) No internet connection, but LAN/WLAN available: Everything that relies on Cloud Services or APIs will no longer work (e.g. Telegram Binding, Netatmo, …), but e.g. ZWave, Zigbee or knx will still be accessible and controllable through openHAB and bridging technologies or protocols is still available.

b) You completely disconnect the machine from the network: This will keep e.g. ZWave or Zigbee running, but may break other stuff (like knx connection in case you connect through an IP Interface. If you use a serial or USB Interface knx is still possible). Bridging technologies or protocols is still available.

Security System:
OH is not and never has been designed as a security system. Use dedicated hardware and software for such a job. You should never trust any uncertified hard-/software when it comes to security or life support. Insurances will be having fun telling you that your security system will not count when it comes to fee reduction or in case of an incident.

Does this answer your question?