RTS

Radio Technology Somfy, always written RTS, is the 433.42 MHz radio Somfy has shipped in tubular motors for decades. A remote, a wall switch, or a gateway transmits open, close, stop, or the motor’s stored my position, and nothing comes back. It is the reason a house full of motorized shades can be integrated in an afternoon, and the reason the resulting cover entities have to be treated as commands rather than readings.

Strengths

• Enormous installed base. Most existing Somfy shades, awnings, and shutters are RTS, so a retrofit usually needs a gateway rather than new motors.
• Cheap per opening. RTS motors cost less than their io-homecontrol equivalents, which is why fabricators default to them.
• Many control points. A single motor accepts a dozen paired transmitters, so handsets, wall switches, sun sensors, and a gateway can coexist without arguing.
• The my position. One favourite intermediate position is stored in the motor itself, so a scene can reach a half-open slat angle even though nothing else about the motor is readable.

Trade-offs

• No feedback, ever. RTS is one-way, so Home Assistant cannot track an RTS cover’s state after controlling it. Its own documentation’s answer is a template cover holding an optimistic open or closed state next to the real one, which is right exactly as long as every command gets through.
• Assumed state spreads. Any automation that branches on a cover’s position is really branching on whatever state was assumed for it, so sun-tracking and occupancy logic drift over a day.
• No battery or diagnostics. A battery RTS motor reports no level, so charge state lives on a maintenance schedule rather than in a sensor.
• Reversed motors happen. A motor wired or programmed in reverse presents as up when it is down, which is fixed per device in the integration’s options rather than at the motor.

RTS in Home Assistant

RTS reaches Home Assistant through a gateway: Overkiz for Somfy TaHoma and Connexoon RTS boxes and for the white-label Overkiz vendors, or Somfy MyLink for the older North American myLink bridge. Both give covers without state. Where a scene genuinely depends on a shade’s position, the answer is either an io-homecontrol or Zigbee motor that reports, or an independent sensor that does; in a Selora install RTS is treated as a control path for existing hardware, not as the basis for state-dependent automation.