Parallel Switching - Light fittings

[SimonH2]

What happens if the connection to the cloud is lost ? ( or the sun comes out and the cloud(s) disappear ).

A well designed system won't care - the only things lost would be features like remote control or monitoring.
However, many systems these days have gratuitous requirements for cloud access - your "local" system sends commands out to some provider's server which then sends commands back to your devices. I would not install anything like that - ask Revolv users what they thought when Google turned off the servers and the Revolv hubs became bricks overnight
There's plenty of options that don't need the cloud.

Hi, this is a feature I have seen in a number of Building Management Systems (BMS) to turn on all lights to max when the fire alarm sounds.
This would normally be done by the light switches being ethernet connected to the BMS which then switches the relays for the lights.

Depending on requirements, DALI might be worth considering. It's a well established industry standard, with a wide variety of devices (inputs, controllers, and luminaires/drivers) available. Either add the "all on" input to the main controller, or as DALI is multi-master, a separate master could signal all devices to turn on. The big problem with the latter option is how to return all the lighting to it's previous setting rather than all off.

 

[davelx]

if you want a RR solution look at the eDIN product range from Mode Lighting.

http://edincontrols.co.uk/