I've never played with Omni-Bus but it sounds like something that would work?
A bit different in that the network runs on LV and manages HV. That said you could just do an LV to LV relay thing with it.
Yeah here today have mostly UPB lighting controls. That said also have Z-wave, Zigbee and X-10 plugged into the Leviton HAI OPII panel.
Popular in domestic commercial operations and a variety of international applications, Omni-Bus controls up to 256 lights, shades, fans, shutters, pumps, and more. Utilizing the worldwide DIN rail standard for mounting, this bus and controller based management family controls CFL, LED, electronic low voltage, Halogen, and incandescent lighting. Modular Omni-Bus components can be located where needed to save wiring and installation costs.
Elegant, multi-button programmable wall switches eliminate the expense of in-wall high voltage wiring to multi-way switches. Whereas competing central lighting systems require home runs to a single central cabinet, Omni-Bus power wiring is minimized as controllers can be localized to switches and switches can be programmed to perform a number of actions. Omni-Bus architecture includes low cost splitters and T-connections for ease of installation and expandability. Omni-Bus network can be star, hub and spoke, daisy chain or a combination.
How does it work? Power modules feed power to dimming or non-dimming switches. Each wireless or wired switch connects to a DIN rail module. Load Control and other DIN rail modules connect to the Omni-Bus network using standard CAT-5 UTP cable. The Omni-Bus network runs on a low supply voltage (24VDC) and is optically isolated from the mains supply side. Each hardwired switch connects to the Omni-Bus networking using CAT-5. Splitters allow for a free topology architecture. Versatility that's perfect for small businesses, featuring the benefits of central lighting control with the flexibility of distributed control systems.
Omni-Bus features free setup software available online. Each hard-wired or wireless device works in 110/220/240V 50-60Hz markets unless otherwise noted. All modules are CE, FCC, UL (ETL) approved.
Leviton HAI Omni-Bus