Elsner
German multi-sensor weather stations for KNX — the industry standard for solar shading and blind automation.
Elsner Elektronik (Gärtringen, Germany — founded 1972) specialises in building automation sensors — primarily combined weather stations that measure solar radiation, wind speed, rain/wet detection, temperature and twilight in a single bus-powered device. Their flagship P04-KNX-GPS series is the most commonly specified weather station in European KNX projects: a compact outdoor unit with up to 4 sun sensors (for facades facing different directions), anemometer, tipping-bucket rain detector, and NTC temperature probe. All measurement data is available on the KNX TP bus as standardised DPTs, making them directly addressable by KNX blinds actuators, logic blocks in MDT or Gira devices, and ETS6 programming.
Role in our panels
How we use Elsner
Elsner weather stations connect directly to the KNX TP bus (no gateway required) and send measurement values as regular KNX telegrams on configurable group addresses. The P04-KNX-GPS includes a GPS module for automatic summer/winter time switching and accurate astronomical sun position calculation (azimuth and elevation) — enabling slat-angle control that tracks the sun path without manual seasonal adjustments. The WS1 and WS2 series (Modbus RTU) serve industrial and BMS projects where KNX is not the primary protocol. For blind control, Elsner sensors pair with any KNX blinds actuator (MDT JAL-04UP, Hager TXA661B, ABB SA/M) — the ETS6 logic block in the blinds actuator reads the sensor DPTs and executes the shading strategy without a separate controller.
In KNX panels, Elsner P04 sensors do not require panel hardware — they connect directly to the KNX TP bus at the installation point (roof or facade). Panel design consideration: include a KNX PSU with sufficient current budget (P04-KNX-GPS draws ~10mA from the bus). The logical integration in ETS6: (1) P04 sun intensity (lux) → linked to blinds actuator group address 'sun sensor' → actuator lowers blinds when lux exceeds threshold (e.g., 50,000 lux); (2) P04 wind speed (m/s) → linked to actuator 'wind alarm' → actuator retracts blinds above threshold and locks them for 10 minutes; (3) P04 rain (binary) → linked to 'rain alarm' → retracts all outdoor blinds and blocks manual override for 30 minutes; (4) P04 twilight (lux) → linked to KNX outdoor lighting group address for dawn/dusk switching. All thresholds configured in ETS6 parameters of the blinds actuator — no separate logic block required.
Used in these project types
Elsner products
Key components we install
Elsner P04-KNX-GPS
Flagship KNX weather station with 4-direction sun sensors, anemometer, rain detector, temperature sensor and GPS for precise sun tracking. Sends sun azimuth, elevation, 4× lux values, wind speed, rain detection, outside temperature directly to KNX bus. The standard specification for KNX projects with exterior blinds/shutters. Roof or wall mount. Bus-powered.
Elsner P04-M-KNX
Mast-mount version of P04 for installations without wall access (e.g., flat roof). Identical sensor set to P04-KNX-GPS. Includes 1m mounting mast. Common in commercial buildings and apartment blocks where roof-mounted installation is preferred.
Elsner WS1 Modbus
Modbus RTU RS-485 version for integration with building management systems (Siemens Desigo, Schneider EcoStruxure) or Home Assistant/Node-RED. Same sensor set as P04. Used when KNX is not the primary protocol, or for monitoring alongside a non-KNX BMS. Pairs with Modbus-KNX gateway for dual-protocol projects.
Elsner SUNTRACER KNX-S
Dedicated sun position tracker with astronomical clock and KNX interface. No sensors — calculates sun position from GPS coordinates, date and time. Sends azimuth and elevation to KNX bus for slat angle optimisation without physical sun sensor. Used in shading projects where aesthetics prevent external sensor installation.
Elsner CARMA KNX-S
Room-level multi-sensor: temperature, humidity, CO2, VOC, illuminance and presence in one device. KNX bus-powered. For office and hotel room control: HVAC setpoint feedback, ventilation demand based on CO2, lighting dimming based on measured lux. Complements outdoor weather station in complete KNX building projects.
Elsner FAQ
Can one Elsner P04 serve an entire building's blinds?
Yes — the P04 broadcasts its sensor values on KNX group addresses. Any number of blinds actuators across the building can subscribe to the same group addresses. The wind alarm telegram, for example, can simultaneously retract all external blinds on all floors. Facade-specific sun shading requires either 4-direction sun sensors on a single P04 (south, east, west, north) or facade-mounted sensors on each exposure.
How does the GPS sun tracking work?
The P04-KNX-GPS contains a GPS receiver that determines the installation location (longitude, latitude) and precise UTC time. From this, it calculates the sun's current azimuth and elevation using the NOAA solar position algorithm. These values are sent as KNX telegrams (DPT 9.001 for angles in degrees). The blinds actuator uses the azimuth to determine which facade is exposed and the elevation to calculate the optimal slat angle — no manual seasonal adjustment required.
What are the typical KNX group addresses for P04 data?
P04-KNX-GPS typically sends: Sun South lux (DPT 9.004), Sun East lux (DPT 9.004), Sun West lux (DPT 9.004), Wind speed m/s (DPT 9.005), Rain binary (DPT 1.002), Outside temperature °C (DPT 9.001), Twilight lux (DPT 9.004), Sun azimuth degrees (DPT 9.001), Sun elevation degrees (DPT 9.001), Time/date (DPT 10/11). All are configured in ETS6 under the Elsner device parameter page — assign to your project's GA structure.
Does Elsner work with all KNX blinds actuators?
Yes — Elsner sensor data uses standard KNX DPTs, so any IEC 14543-3 compliant KNX blinds actuator (MDT, Hager, ABB, Siemens, Gira, Weinzierl) can use it. The specific blind control logic (threshold values, hysteresis, priority rules) is configured in the actuator parameters, not in the Elsner sensor. Some actuators (MDT JAL-04UP, Gira 2138) have integrated sun/wind logic blocks with timer functions — pair directly with Elsner group addresses.
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