Short answer: Schedule the Glydea ULTRA 35 DCT 1246115 for drapes up to 35 kg (77 lb) on 10 m of track, or the Glydea ULTRA 60 DCT 1246117 up to 60 kg (132 lb) on 12 m. Add one RS485 (SDN, 2-way) module 1871412 per motor, run Cat5e no longer than 65 ft from an SDN device port, and keep tandem pairs off SDN.
Drapery is the line item that blows up a shade commissioning day. The motor arrives, the BMS team expects an SDN node, and someone finds out the drape is a tandem pair or the motor index needs a different module. Each of those is a change order. Here is the spec that prevents all of them.
Free spec package
Glydea ULTRA DCT on SDN: 4-sheet drawing set
- SMD-01 sheet index, general notes and a sourced limits schedule
- SMD-02 motor head and track detail with equipment schedule
- SMD-03 SDN riser, RJ45 pinout, DCT input detail, wiring schedule
- SMD-04 3-part guide spec, BOM and submittal checklist
Pick the motor by drape weight and track length
Glydea ULTRA comes in two sizes, and the number is the load in kilograms. Somfy's curtain databook rates the ULTRA 35 at 35 kg of curtain on up to 10 m of track with 0.6 Nm of torque. The ULTRA 60 carries 60 kg on up to 12 m with 1.0 Nm. Somfy US quotes the range at up to 132 lb of traversing capacity.
| Item | ULTRA 35 DCT 1246115 | ULTRA 60 DCT 1246117 |
|---|---|---|
| Max curtain weight | 35 kg (77 lb) | 60 kg (132 lb) |
| Max track length | 10 m (32.8 ft) | 12 m (39.4 ft) |
| Power in operation | 30 W | 60 W |
| Standby | 0.5 W | 0.5 W |
| Noise level | 38 dB | 38 dB |
| Supply | 90-240 V, 10 ft plug | 90-240 V, 10 ft plug |
Both motors carry IP 30 and cTUVus, so they are indoor products. Somfy backs each with a 5-year warranty. The databook lists five speeds from 7.5 cm/s in silent mode up to 20 cm/s, and a 300 mm minimum bend radius for curved track.
Our rule: get the fabric weight per linear foot from the workroom before you release the motor schedule. Pick the ULTRA 35 only when weight and track length both fit inside its rating. Anything close goes to the ULTRA 60.
Start with dry contact, then decide on SDN
DCT means the motor takes low-voltage dry contact inputs through its RJ12 port. Somfy's databook allows three ways to wire it: two normally open contacts where closing both gives stop, two contacts with stop wired in parallel, or three contacts for open, stop and close.
The databook also sets the cable limits. Modular AWG 24 or Cat5 runs reach 100 m and 10 motors. Heavier 0.75 mm² conductors reach 200 m and 20 motors. A keypad wall or a relay output from a lighting panel covers plenty of rooms on DCT alone.
SDN earns its place once the owner wants position feedback, presets or one network for shades and drapes. Somfy calls the module its first bi-directional drapery solution.
Add SDN with one 1871412 module per motor
The 1871412 module plugs into the bottom of the motor head and draws its power from the motor. No separate 24V feed. Somfy lists it for exactly two US motors: 1246115 and 1246117. It translates SDN commands into open, close, stop, step and favorite positions, and it holds up to 16 SDN group addresses.
Check the motor index letter on the label first. Somfy's databook matches index F RTS or DCT motors to 1871412, and index E or earlier motors to 1870275. Somfy has replaced 1870275 with 1871412. On a retrofit with older motors, read the label before you order.
Run the bus leg: Cat5e, 65 ft, pins 1, 2 and 8
Somfy states the module connects to any device port on the SDN bus. A PowerConnect 1871026 panel carries two device ports, so one panel feeds two drapes with no extra hardware. Somfy's module guide calls for Cat5e or higher with the leg not exceeding 65 ft. The in-box instructions put the same limit at 20 m and print the pinout.
Glydea ULTRA on SDN: the hard numbers
- 35 kg (77 lb) / 10 m ULTRA 35. 60 kg (132 lb) / 12 m ULTRA 60.
- 1 module 1871412 per motor, powered by the motor.
- 65 ft (20 m) max RS485 leg, Cat5e or higher.
- Pin 1 +RS485, pin 2 -RS485, pin 8 GND. Pins 3-7 unused.
- 16 SDN group addresses per module.
- 0 tandem pairs on SDN. Tandem is DCT or WT only.
Bus termination, segment loading and panel counts follow the normal SDN rules. Our SDN wiring rules guide covers those. Our rule: put the drape's outlet and the Cat5e drop on the same coordination drawing, at the motor end of the track.
Tandem drapes stay off SDN
This is the line that catches estimators. Somfy's databook supports tandem operation on WT and DCT motors and states that RS485 and Zigbee modules do not support tandem. A heavy stage curtain or a wide double-motor track cannot become an SDN node.
The fix costs less than the change order. Keep the tandem pair on dry contact and give the BMS a relay output into the DCT inputs. Flag every tandem opening on the drape schedule before submittal, so nobody prices a module that will sit in a box.
Commission limits first, addresses second
Hang the drape before power-up. Somfy's guide says the first open or close command makes the motor run to both hard stops and record them. Drape weight and type can call for a trim afterward.
Under dry contact, adjust limits with the DCT setting tool 9014599. Somfy's module instructions point to the RS485 setting tool 9017142 for setting the motor once the module is in. Address and group assignment happen in Set pro by Somfy through the USB to RS485 adaptor 9015260. Power the motor down before you insert the module.
Our rule: record the motor reference, the index letter and the SDN group on a label inside the head cover. The next tech saves an hour.
Put these items on the submittal
Somfy covers drapery in guide spec section 12 22 00 Curtains and Drapes. Our drawing set adds the Glydea ULTRA pieces as editable lines. Submit these items:
- Drape schedule with weight and track length per opening, and the motor size picked for each
- Tandem openings flagged as DCT, with the BMS relay point listed
- SDN riser showing each device port leg and its length
- Group address map, 1 to 16 per module
Take the spec package to your submittal
Glydea ULTRA DCT on SDN: 4-sheet drawing set
- SMD-01 sheet index, general notes and a sourced limits schedule
- SMD-02 motor head and track detail with equipment schedule
- SMD-03 SDN riser, RJ45 pinout, DCT input detail, wiring schedule
- SMD-04 3-part guide spec, BOM and submittal checklist
FAQ
Does the 1871412 module need its own power supply?
No. Somfy states the module draws its power from the Glydea ULTRA motor. You run Cat5e for data from an SDN device port, up to 65 ft.
Can a tandem Glydea ULTRA pair run on SDN?
No. Somfy's curtain databook states that RS485 and Zigbee modules do not support tandem operation. Tandem pairs run on DCT or WT control.
Which module fits an older Glydea ULTRA motor?
Read the index letter on the motor label. Somfy matches index F motors to 1871412 and index E or earlier motors to 1870275, which Somfy has replaced with 1871412.
How heavy a drape can a Glydea ULTRA 60 move?
Somfy rates the ULTRA 60 at 60 kg, about 132 lb, of curtain on up to 12 m of track. The ULTRA 35 is rated 35 kg on up to 10 m.
Sources: somfysystems.com product pages 1246115, 1246117, 1871412 and 1870275; Somfy curtain databook (Feb 2026); Somfy SDN RS485 module in-box instructions 5040192A; Somfy SDN Module for Glydea ULTRA installation guide; Somfy news posts of Oct 9 2020 (SDN components for drapery motors) and Apr 8 2022 (Glydea ULTRA range).
Ryan Towns writes the Somfy Integrator Guides for ShadeMotorsDirect, an authorized Somfy distributor. Questions on a spec or a retrofit: 859-414-6872 or colin@shademotorsdirect.com, 8:00 AM - 7:30 PM ET.
