If the hub is unavailable
The Fibaro, like all of the micro relays, will control current directly if it is directly attached to it. So it can work when the Internet is down, or when the hub is gone altogether, as a regular physical switch. Just like a non-network switch. But only for the circuit it is directly attached to. So as long as you have attached a physical button to that circuit, you can still toggle the lights on and off even if the hub is missing altogether. Dimming depends on the exact physical device it’s been attached.
If you use any of the other types of control features available through SmartThings, such as saying when I turn on the switch in the entry, I want those lights to come on and I want the kitchen lights to also come on (which are actually on a different circuit and being told to follow the switch by the smart things hub) and the hub is not available, then the entry lights would still come on, but the kitchen lights would not until you went over and hit their physical switch. Anything based on schedules would not operate if the hub was not available.
If the hub is available, but the internet is not
If a device type is approved for “local processing” (not local connection which is a different thing) then, if the hub is available but the smartthings cloud is not, the automations that you set up that were approved for local processing will still run. So in this example, if you turned on the entryway switch, the lights in the kitchen and the entryway both come on even if the Internet was not available. Schedules set up through the smartlights smartapp would also continue to run.
@aaron @slagle can you please confirm that the micro relays that are listed on the official "works with "SmartThings list for the UK will run locally with smart lights automations?
custom code never runs when the Internet is not available. That includes custom device types.
That said, no custom code or custom device type has the option to run locally at the present time. In fact, the only thing which does run locally are approved device types with the smart lighting automation.
The reason is that the only code that can run locally when the Internet is not available are those which are already loaded into the firmware for the hub and present for all customers. As soon as a single change is made, that code is no longer pushed out to all customers, and therefore it is not available in the firmware.
So only the Fibaro models that are on the official compatibility list are even eligible for local processing. the new fibaro is not on that list, and therefore it cannot run locally at the present time.
Getting a device approved to run when the Internet is down
So the process timeline typically looks like this: manufacturer introduces new device. Community members develop custom code for a device type for that new device, and share it with others through the forum.
When it seems fully ready for general use, the author submits it to SmartThings for official publication. Once it is officially published, it automatically appears in the SmartThings mobile app.
It then becomes eligible for review as a candidate for local processing.
Eventually, it may be selected for local processing, or for technical reasons, it may not.
(There is also a completely separate process through the SmartThings official testing labs, where the manufacturers submit their devices to SmartThings for certification, and the staff do all the device type development and testing. The community only hears about those when there is an official announcement that a new device type has been approved. Those are immediately available in the mobile app, but again may not necessarily be available for local processing.
Announcements of new compatible products are made on the official SmartThings blog, in the announcements section of this form, and of course are added to the compatibility list. )