Short answer: Pick the Somfy hub by the radio your motors speak. The Somfy TaHoma Switch (1871037) runs RTS and Zigbee shades from one app, up to 40 RTS channels and 60 Zigbee products. A URTSI II (1810872) hands RTS channels to a serial control system. A UAI Plus (1870272) commissions wired SDN motors over IP for Control4, Crestron or Savant.
Four Somfy boxes share the word "hub" in search results, and they solve four different jobs. Two of them talk to shades over the air. One turns serial commands from a control processor into RTS radio. The fourth has no radio and addresses wired motors on a data bus.
Start from the motor label, then pick the box. The sections below walk the decision in that order and finish with a side-by-side table.
Start with the motors you already own
Somfy builds motors on three control families, and each hub serves a different mix of them. RTS motors carry a one-way 433.420 MHz receiver and pair to handheld remotes. Zigbee motors run two-way Zigbee 3.0 and report their position back. SDN motors (the RS485 models in the Sonesse and Glydea ULTRA ranges) have no radio and take commands over a wired network.
The RTS vs Zigbee comparison covers the radio side in depth. For hub selection the short version holds:
- RTS or Zigbee shades, controlled from a phone or a voice assistant: TaHoma Switch.
- RTS shades inside a Control4 or Crestron system that sends RS232, RS485 or IR commands: URTSI II.
- SDN RS485 motors on a commercial or high-end residential job: UAI Plus.
- A house that already runs an older TaHoma interface or a myLink: the TaHoma Switch is the upgrade.
TaHoma Switch: the Somfy hub for RTS and Zigbee homes
The Somfy TaHoma Switch (1871037) is the hub Somfy builds for app and voice control today. It carries both radios in one housing, so a retrofit that adds new Zigbee motors to a house full of RTS shades runs from a single TaHoma app.
Somfy publishes two separate capacity limits: up to 60 Somfy Zigbee products and 40 RTS channels. An RTS channel can hold several motors that move as a group, so 40 channels often covers more than 40 windows. Up to 10 TaHoma Switches join for multi-zone RTS control on a large house.
Voice runs through Amazon Alexa and Google Home, with Apple Home available on select Zigbee motors. The integration list reaches the platforms most integrators already have on site: Control4, Crestron, Savant, Elan, RTI, URC and Brilliant, plus Philips Hue, SmartThings, Sonos, Alarm.com, Josh.ai and Clare Controls.
The hub joins the house network over Wi-Fi. For an equipment rack with a weak signal, order the Somfy TaHoma Switch with Ethernet Adaptor (1871038) and put it on a wired drop. Somfy backs the TaHoma Switch with a 5-year warranty.
Zigbee shades gain a handheld through the Somfy Ysia 5 Channel Zigbee Remote (1871154), which sits on the same mesh as the motors. Setup steps, pairing and capacity planning for this hub live in the TaHoma Switch setup guide.
The earlier TaHoma interface and myLink, replaced by TaHoma Switch
Many searches for "TaHoma Beecon" or "TaHoma hub" point at the earlier Somfy TaHoma RTS/Zigbee interface (1811731). Somfy's spec sheet for that unit lists 40 RTS channels, up to 50 Zigbee devices, 2.4 GHz Wi-Fi with an optional Ethernet adaptor, and up to 40 scenes and 40 schedules. It works with Alexa, Google Assistant and Control4.
Somfy has moved its lineup on to the TaHoma Switch, and the newer hub improves on each of those figures that matter to a buyer. It holds 60 Zigbee products instead of 50, adds Apple Home for select Zigbee motors, and widens the integration list. A 1811731 already installed keeps running its RTS channels. A new project or a replacement should start on the TaHoma Switch.
The same path applies to myLink. Somfy's myLink bridged Wi-Fi to RTS at 16 channels per unit and is now retired from the Somfy range. The TaHoma Switch covers 40 RTS channels on one unit and brings Zigbee along with it, so a myLink owner gains more than two times the RTS capacity from a single box.
Existing RTS remotes stay useful through either move. The motor keeps its paired transmitters, and the hub joins as one more.
URTSI II: RTS channels for a serial control system
The Somfy Universal RTS Interface II, URTSI II (1810872) has no app. It sits beside a control processor and converts RS232, RS485 or IR commands into RTS radio signals, which lets a Control4, Crestron or Savant programmer drive Somfy RTS shades from a keypad or touch panel.
One unit carries 16 RTS channels, each controlled on its own or as a group. Somfy allows up to 16 URTSI units on one system for 256 channels, cascaded over RS485. Somfy rates the transmitter for a 65 ft radius under optimal conditions, which is a reason to mount it near the shades it drives rather than deep in a rack.
Each URTSI channel joins a motor the way a new remote does, through the motor's programming mode. Somfy's URTSI II operating instructions give the sequence. Somfy lists the URTSI II as compatible with its RTS motors and receivers, and covers it for 5 years.
Integrators choose the URTSI II over the TaHoma Switch for two reasons. The control system talks serial or IR and has no IP driver in the project, or the job needs more than 40 RTS channels on a single serial path.
UAI Plus: commissioning for SDN motors
The Somfy Connect Universal Automation Interface (UAI) Plus (1870272) serves a different family of motors. SDN motors run on a wired RS485 network, and the UAI Plus commissions, groups and controls up to 250 of them over IP.
Somfy lists the Sonesse 30 RS485, the Sonesse 50 ULTRA AC and DC RS485, Glydea ULTRA, and Irismo 35 with the SDN enclosure kit as compatible motors. The interface speaks SDN 2.0 and the Somfy Synergy API, and Somfy names Control4, Crestron and Savant as the automation platforms it serves.
Embedded programming software replaces the converters and pinouts older SDN jobs needed. A setup wizard handles commissioning, grouping works by drag and drop, and firmware updates arrive over IP. The unit takes 12 to 24V DC input and reaches up to 328 ft from the router on standard Cat5e.
Specify the UAI Plus for commercial floors, conference rooms and projection-screen installs where the shade motors are already SDN. For wiring and motor background, the guide to Somfy control systems sets SDN beside RTS, Zigbee and wired control.
Somfy hubs and interfaces side by side
| TaHoma Switch (1871037) | RTS and Zigbee. 40 RTS channels and 60 Zigbee products. Wi-Fi, Ethernet with 1871038. TaHoma app, Alexa, Google Home, Apple Home on select Zigbee motors. Current Somfy hub. |
| TaHoma interface (1811731) | RTS and Zigbee. 40 RTS channels and 50 Zigbee devices. 2.4 GHz Wi-Fi, optional Ethernet. Replaced by the TaHoma Switch. |
| myLink | RTS only. 16 channels per unit. Wi-Fi. Replaced by the TaHoma Switch. |
| URTSI II (1810872) | RTS only. 16 channels per unit, up to 256 with 16 units. RS232, RS485 and IR input from a control system. No app. |
| UAI Plus (1870272) | SDN RS485 motors. Up to 250 motors over IP. Control4, Crestron, Savant through the Synergy API. 12 to 24V DC. |
The full range sits in our Somfy smart hubs and gateways collection.
Mixing interfaces on one project
Large jobs often run two of these at once. A home with SDN shades in the theater and RTS awnings outside can pair a UAI Plus for the wired motors with a URTSI II or a TaHoma Switch for the radio side, and let the control processor tie both into one scene.
Count before you order. Tally Zigbee motors one by one, RTS by channel, and SDN motors by address. Then match each count to the limits in the table and add a unit wherever a count runs over.
Questions we get on Somfy hubs
Is the TaHoma Switch the same as the TaHoma Beecon?
No. The TaHoma Switch (1871037) is Somfy's current hub, with 40 RTS channels and 60 Zigbee products, Apple Home on select Zigbee motors, and an Ethernet option. The earlier TaHoma interface (1811731), often listed as TaHoma Beecon, carried 40 RTS channels and 50 Zigbee devices. The TaHoma Switch replaces it.
Do I need a URTSI if I already have a TaHoma Switch?
Only if your control system sends RS232, RS485 or IR commands and has no IP driver for TaHoma, or the job needs more than 40 RTS channels on one serial path. The URTSI II gives 16 channels per unit and scales to 256 with 16 units. For app and voice control, the TaHoma Switch does the job alone.
Can the TaHoma Switch control SDN RS485 motors?
Somfy publishes the TaHoma Switch for RTS and Zigbee motors. SDN RS485 motors run on a wired bus, and Somfy's interface for them is the UAI Plus (1870272), which commissions up to 250 SDN motors over IP and hands them to Control4, Crestron or Savant through the Somfy Synergy API.
What replaced the Somfy myLink?
Somfy retired myLink, a Wi-Fi-to-RTS bridge with 16 channels per unit, and the TaHoma family took its place. Today that means the TaHoma Switch (1871037), which runs 40 RTS channels plus 60 Zigbee products from the TaHoma app. Paired RTS remotes keep working after the change, since the hub joins each motor as another transmitter.
Sources: Somfy product records for TaHoma switch 1871037, URTSI II 1810872 and UAI Plus 1870272 (somfysystems.com, somfypro.com); Somfy TaHoma RTS/Zigbee spec sheet 1/2022; Somfy URTSI spec sheet; Somfy Connect UAI Plus spec sheet; Somfy myLink legacy spec sheet.
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