KNX Blinds Actuators: Selection, Wiring and ETS6 Commissioning
Every external blind, roller shutter, awning and venetian blind in a KNX project needs one actuator channel per motor — sizing this correctly and commissioning travel time, sun logic and wind alarm inputs determines whether the installation performs reliably for decades.
Actuator channel types
KNX blinds actuators use one of three output technologies depending on the motor type being driven. Choosing the wrong output type means the motor either will not run at all or will run without position feedback, making slat angle control impossible.
| Channel type | Output | Motor compatibility | Slat angle | Notes |
|---|---|---|---|---|
| 230V relay pair (UP/DOWN) | Two 230V AC relays, interlocked | Standard AC tubular motors (Somfy, Becker, Elero, generic) | Via travel time only — no encoder | Most common. Motor has no feedback signal. Position tracked by timed travel fraction. |
| 0–10V analog output | 0–10V DC signal to motor controller | Motors with 0–10V speed/position input (Geze, Roto window drives) | Via 0–10V setpoint (0V = closed, 10V = open) | Less common for blinds, more used for window drives and dampers. |
| KNX motor with encoder | KNX TP bus connection direct to motor | KNX-native motors (Somfy KNX io, Nice KNX, CAME KNX) | Exact position via encoder feedback, DPT 5.001 | Most precise. Motor reports actual position. Higher cost per channel. No separate actuator needed. |
For the vast majority of European residential and commercial projects, 230V relay pair actuators with standard AC tubular motors are the correct choice — cost-effective, universally compatible, and fully supported by all major KNX manufacturers. KNX-native motors with encoders are appropriate for premium projects where exact position reporting and energy metering are required.
Product comparison — leading KNX blinds actuators
The four most widely specified KNX blinds actuators in the European market cover all typical project sizes from 4-channel residential to 6-channel commercial floors.
| Model | Channels | Max motor current | Sun logic built-in | Wind alarm input | Slat angle DPT | ETS support |
|---|---|---|---|---|---|---|
| MDT JAL-04UP.02 | 4 ch | 2 A per channel | Yes — full sun logic block | Yes — via KNX GA | DPT 5.001 | ETS4 + ETS6 |
| Hager TXA661B | 6 ch | 2 A per channel | Partial — lux threshold only | Yes — via KNX GA | DPT 5.001 | ETS5 + ETS6 |
| ABB SA/M 4.16.5.1 | 4 ch | 2 A per channel | Yes — sun function block | Yes — via KNX GA | DPT 5.001 | ETS4 + ETS6 |
| Siemens 5WG1 237-1AB01 | 4 ch | 2 A per channel | No — requires external logic | Yes — via KNX GA | DPT 5.001 | ETS4 + ETS6 |
MDT JAL-04UP.02 is the most specified actuator in German-speaking markets due to its comprehensive sun logic block configurable entirely within ETS6 — no external logic engine required. ABB SA/M is preferred for projects already using ABB i-bus KNX panels for consistency of platform.
Travel time calibration
Travel time is the number of seconds the motor takes to move the blind from fully open to fully closed (or vice versa). It is the only position reference for relay-pair actuators — get it wrong and position commands will be inaccurate.
Manual calibration procedure
Send DOWN command to motor — run to fully closed lower limit (motor stalls against limit switch).
Reset timer to zero. Send UP command. Start stopwatch simultaneously.
Motor drives blind to fully open upper limit (stalls again). Stop stopwatch.
Record travel time in seconds (typically 20–60 s depending on blind height and motor speed).
Enter this value in ETS6 parameter 'Travel time UP/DOWN' for that channel. Add 2 s margin to ensure full travel before stall.
Verify: send 50% position command → blind should stop at visual mid-point ±5%.
Automatic reference run — preferred method
The MDT JAL-04UP.02 and ABB SA/M support automatic reference run: press the dedicated ETS commissioning button for 3 seconds. The actuator drives to the lower limit, then to the upper limit, measuring and storing travel time automatically. This eliminates manual stopwatch error and accounts for asymmetric UP vs DOWN motor speeds — which differ on most tubular motors by 5–15%. After the reference run, travel time UP and travel time DOWN are stored separately for accurate bidirectional positioning.
Slat angle — DPT 5.001
Slat angle for venetian blinds (Raffstore) is communicated via DPT 5.001, an 8-bit unsigned integer where 0 represents 0% and 255 represents 100%. In practice, ETS and visualization systems use the percentage value directly.
0% (DPT value 0)
Slats horizontal — maximum light block, minimum view through. For south-facing Raffstore at solar noon this is the target angle at high sun elevation.
50% (DPT value 128)
Slats at 45° — glare reduction while maintaining partial view through the blind. The most common daytime setpoint for occupied offices.
100% (DPT value 255)
Slats fully open (vertical) — maximum daylight transmission, no solar shading. Used when sun is not on the facade or outside shading hours.
The slat angle DPT 5.001 value is sent on a separate group address from the blind position DPT 5.001 value. A Raffstore actuator channel therefore requires at minimum three group addresses: position (%), slat angle (%), and move direction (DPT 1.008 — up/down). The MDT JAL-04UP.02 supports all three from a single channel.
Sun logic in MDT JAL-04UP — ETS6 parameters
The MDT JAL-04UP.02 contains a built-in sun logic function block configurable entirely within ETS6 — no separate logic engine required. This makes it the preferred choice for projects where each facade needs independent shading logic without external HA or logic module.
| ETS6 parameter | Group address | DPT | Typical value | Description |
|---|---|---|---|---|
| Sun enable | GA from Elsner P04 | DPT 1.001 | 1 = shade, 0 = retract | Master on/off for sun logic — linked to Elsner P04 'sun active' telegram per facade. |
| Lux threshold | Internal parameter | — | 40,000 lx | Minimum brightness at which sun logic activates. Below this, blind retracts regardless of azimuth. |
| Hold time | Internal parameter | — | 10 min | Delay before retracting on cloud. Prevents constant movement on passing clouds. |
| Facade orientation | Internal parameter | ° | 180° (south) | Facade azimuth in degrees. Used together with azimuth input to determine sun-on-facade condition. |
| Azimuth min/max | Internal parameter | ° | 90°–270° (south) | Sun azimuth range where this facade is exposed. Outside range: blind retracts. |
| Elevation min | Internal parameter | ° | 10° | Minimum sun elevation to trigger shading. Below this angle (early morning/late afternoon), no shading. |
| Slat calculation table | Internal parameter | — | See raffstore article | Elevation → slat angle lookup table. Defines exact slat angle at each sun elevation step. |
Wind alarm integration — Elsner P04
All external blinds, awnings and roller shutters must implement wind alarm logic. The Elsner P04-KNX weather station measures wind speed and sends it as DPT 9.005 (wind speed in m/s) on a KNX group address. The blinds actuator monitors this value against a configurable threshold.
Wind speed telegram
Elsner P04 sends DPT 9.005 wind speed telegram cyclically (every 30 s) and on change. Link this GA to the 'Wind speed' input of the MDT JAL-04UP sun logic block.
Alarm threshold
Configurable in ETS6 parameter 'Wind alarm threshold' — typically 45–60 km/h (12.5–16.7 m/s) for standard roller shutters; 35 km/h for awnings (lower wind resistance). Check blind manufacturer specification.
Alarm action
When wind speed exceeds threshold: actuator drives blind to fully retracted (UP) position. This is a priority command — overrides sun logic, manual override, scene, and time schedule.
Hold time after alarm
After wind drops below threshold, actuator waits a configurable hold time (default 10 minutes, recommended minimum) before allowing re-extension. This prevents cycling in gusty conditions.
Priority order
Wind alarm (highest priority) > manual override > sun logic > scene > time schedule (lowest priority). Manual override itself is cleared after a configurable timeout (typically 2 hours) to prevent being left in manual indefinitely.
ETS6 — MDT JAL-04UP wind alarm group address linking
// MDT JAL-04UP.02 — ETS6 group address assignment (per channel) Channel 1 (South facade, Raffstore) Position (%) → GA 4/1/1 (DPT 5.001) Slat angle (%) → GA 4/1/2 (DPT 5.001) Move direction → GA 4/1/3 (DPT 1.008 — 0=UP, 1=DOWN) Stop → GA 4/1/4 (DPT 1.001) Wind speed input → GA 6/0/1 (DPT 9.005 — from Elsner P04) Sun enable input → GA 6/0/5 (DPT 1.001 — from Elsner P04 south) Manual override → GA 4/1/5 (DPT 1.001) Wind alarm status → GA 4/1/9 (DPT 1.001 — feedback) // Elsner P04-KNX group address outputs (same bus) Wind speed → GA 6/0/1 (send → all facade actuators) South sun active → GA 6/0/5 (send → south facade actuators only) West sun active → GA 6/0/6 (send → west facade actuators only)
Panel wiring requirements
Correct panel wiring for blinds actuators is critical — motor inrush current, neutral separation, and DIN-rail slot allocation all affect long-term reliability.
Motor circuit MCB sizing
Use MCB type C4 for groups of 3 or more motors. Type C (high magnetic trip threshold) handles the inrush current of multiple simultaneous motor starts. Type B MCBs trip on motor start — incorrect for motor circuits.
Neutral separation from lighting
Motor circuits must use a dedicated neutral conductor — do NOT share neutral with lighting circuits. Tubular motor EMI during running and reversal causes flicker on shared neutrals and can corrupt KNX bus voltage. Run separate N from the distribution block to each motor group.
L+N+PE to each motor group terminal
Each motor group (4–6 motors on one actuator) needs a dedicated MCB feeding L, a shared N bar terminal for that group, and individual PE conductors to motor chassis. Terminal blocks: Phoenix Contact PT series or equivalent, rated 16A, 2.5 mm² minimum.
Surge protection on outdoor feeds
All motor cables running to external blinds are outdoor and subject to lightning-induced surges. Install SPD Type 2 (e.g. Dehn DEHNguard or Phoenix TERMITRAB 2x2) on the incoming L+N of each motor group MCB. Class II protection, max residual voltage 1.5 kV.
DIN-rail slot allocation
MDT JAL-04UP.02 occupies 4 modules (70 mm). Hager TXA661B occupies 4 modules. Allow 17.5 mm clearance either side of actuator for heat dissipation. For 10-channel installs, plan two actuators with 35 mm gap between them.
ETS6 commissioning checklist
Assign physical address to actuator via ETS6 'Individual address' function — press programming button on device until LED flashes.
Download full application including all parameters and group address links. Verify download completes without errors in ETS6 diagnostics.
Perform automatic reference run: ETS6 → channel → 'Start reference run'. Wait for motor to reach both limits. Verify stored travel times in ETS6 parameter readback.
Test wind alarm: manually send DPT 9.005 value above threshold (e.g. 20 m/s) on wind GA → verify all channels retract and wind alarm status GA reads 1. Send 0 m/s, wait hold time, verify channels return to previous position.
Test sun logic: send sun enable GA = 1, send lux value above threshold → verify blind extends to shade position and slat angle moves to sun logic target. Disable sun (GA = 0) → verify retraction after hold time.
Verify manual override priority: during active sun logic, send manual position command → verify blind moves, manual override status GA = 1. Wait override timeout → verify return to sun logic.
Store commissioning scenes: scene 1 = all up (retracted), scene 2 = sun protection position, scene 3 = night privacy (fully closed). Test each scene via visualization.
Solar shading in your KNX panel
We wire blinds actuator modules with factory-calibrated motor groups, wind alarm inputs pre-connected to the Elsner sensor bus, and surge protection on all outdoor circuit feeds.
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