The HW‑group Light 1Wire‑UNI is a compact and precise indoor light intensity sensor specifically designed to reliably detect changes in lighting conditions – whether for security, monitoring, or process control. With a measurement range of 0 to 100 %, a high‑quality semiconductor sensing element, and convenient 1‑Wire UNI (RJ11) connectivity, this sensor can be easily integrated into existing monitoring infrastructures.

Typical applications include server room monitoring, access detection inside IT cabinets, lighting control in sensitive areas, or indicative measurement of solar irradiance in photovoltaic systems. When combined with Poseidon or Ares devices, the Light 1Wire‑UNI becomes a dependable component of comprehensive monitoring solutions.

Function and Operation

At its core, the sensor features a high‑grade semiconductor detector that measures light intensity from 0 to 100 %. The resolution is 1 %, and the measurement accuracy is ± 10 %. Through the RJ11 interface, readings are transmitted in the 1‑Wire UNI protocol to devices such as Poseidon2 or Ares. The 5 V DC power supply is provided directly via the RJ11 cable, eliminating the need for external power adapters.

Installation and Design

The Light 1Wire‑UNI comes with a 3‑meter connection cable, allowing flexible placement. Its slim housing (9 × 80 × 5 mm) enables discreet wall or rack mounting. Thanks to its unique serial number, multiple sensors can operate in parallel on the same RJ11 bus – ideal for environments with several measurement points.

Typical Applications

• Server room monitoring: Triggering alarms when light levels change, e.g., upon room entry.
• Access control: Detecting light increase in IT cabinets as an indicator of unauthorized access.
• Photovoltaic monitoring: Indicative measurement of solar irradiance for PV system performance optimization.
• Environmental monitoring: Detecting day/night transitions or light intensity in work environments.
• Building automation: Integration into systems for energy‑efficient lighting management.

Technical Specifications

• Measurement range: 0 – 100 % light intensity
• Accuracy: ± 10 %
• Resolution: 1 %
• Sensor element: High‑quality semiconductor
• Interface: 1‑Wire UNI (RJ11)
• Power supply: 5 V DC via RJ11
• Current consumption: approx. 10 mA
• Protection rating: IP23 (indoor use)
• Operating temperature: –30 °C to +85 °C
• Relative humidity: 0 – 100 %
• Cable length: 3 m
• Dimensions: 9 × 80 × 5 mm
• Weight: 58 g
• Mounting: Wall or rack
• Warranty: 24 months

Integration into HW‑group Systems

The Light 1Wire‑UNI is fully compatible with Poseidon2 models (3268, 3468, 4002) and Ares devices (Ares 12 LTE and others). Data can be read via LAN, GSM, SNMP, or Modbus/TCP. Using HWg‑PDMS software, long‑term logging and data evaluation are possible – from trend analysis to automatic Excel export.

Key Advantages

• Easy RJ11 plug‑and‑play installation
• Parallel operation of multiple sensors via unique serial numbers
• Low power consumption (only 10 mA)
• Compact, unobtrusive design
• Versatile use in IT and industrial environments
• Full compatibility with Poseidon and Ares platforms

The HW‑group Light 1Wire‑UNI is the ideal solution for precise, low‑maintenance indoor light monitoring. Whether in IT infrastructure, industrial settings, or PV systems – thanks to plug‑and‑play connection, multi‑sensor support, and robust design, it integrates smoothly into existing monitoring systems and provides reliable real‑time illumination data.