Limited connection over fibre

I've been reading through trying to find a solution to controlling an outbuilding cbus over fibre and nobody really has an answer.

Basically it is a shed 150mtrs from the house, all i need is limited control, mainly to turn floodlights on and off from the house.
I'm wondering if anyone has used an auxiliary input unit with some way of closing dry contacts over ethernet (in this case fibre)

If i have relay channels close at the house end on one side of a 3rd party device, send that over ethernet to the aux input, i can more or less control 4 devices on a relay at the other end.

Any ideas as to what 3rd party device to manage the contact closure over fibre?

 

Spitballing here
One thought may be to use to raspberry Pi's and MQTT (node red) on each. This would require a serial/ethernet interface on each end connected to the Pi and basically it would be two totally separate networks (which it will be anyway with your proposed idea).

you could then use WiFi instead of fibre which would air gap just as well. Fibre could also be used as its only Ethernet between the two Pi's

Now that we have Pi's working with C-Bus (C-Gate etc) I am sure someone could easily create an Ethernet bridge with two of them

 

There are plenty of ethernet to relay modules around. If you had a cbus logic device with a network connection (i.e Colour Touch screen, Wise or SHAC) you could write some simple logic to control the relays in response to a cbus group address change.