The HW group Expander 4xDI 1W‑UNI is a compact expansion module that provides up to four potential‑free dry‑contact inputs for monitoring systems. Via the 1‑Wire UNI bus (RJ11), the Expander integrates seamlessly with devices such as Poseidon2, Ares, or STE2. This enables flexible digital input expansion for security and remote monitoring systems — ideal for data centers, industrial facilities, and smart buildings.

Functionality and Applications

The Expander 4xDI 1W‑UNI allows four external sensors — such as door contacts, smoke detectors, or buttons — to be connected directly to existing HW group devices. Communicating via the 1‑Wire UNI bus, the module accurately transmits digital status signals to the connected host device. Multiple modules can be chained together, allowing easy scalability of monitoring capacity.

The Expander is fully bus‑powered, requiring no separate power supply, but can optionally be powered by an external 5 V adapter when more than two units are connected in parallel. This makes it ideal for installations in demanding or energy‑efficient infrastructures.

Typical Applications:

• Server rooms & data centers – expansion for door, smoke, or water‑leak monitoring
• Industrial facilities – monitoring machinery, cabinet doors, and safety signals
• Building management – door and window status feedback in smart‑building systems
• Remote monitoring – integration with Poseidon2 or Ares for alerts via email, SMS, or SNMP
• Security systems – connecting detectors for access control and alarm activation

Key Features of the Expander 4xDI 1W‑UNI

• Four digital inputs for potential‑free contacts (NO/NC dry contacts)
• Dual RJ11 ports for easy daisy‑chain connection
• 1‑Wire UNI communication – compatible with Poseidon2 and Ares
• Bus‑powered via 1‑Wire UNI (or optional external 5 V power adapter under heavy load)
• Sampling rate: 1 second for fast status updates
• Utilizes 4 sensor slots on the 1‑Wire UNI bus
• Robust compact design – optional industrial metal housing
• Supplied with 3 m RJ11 cable

Technical Specifications

• Inputs: 4× potential‑free contacts (NO/NC, sensitivity 0–500 Ω for ON)
• Interface: 1‑Wire UNI (2× RJ11)
• Compatibility: Poseidon 2250, Poseidon 4002, Poseidon2, Ares 12/14, STE2
• Power supply: via bus or optional external 5 V adapter
• Max cable length: 60 m per port (total)
• Sampling interval: 1 second
• Operating environment: –40 °C to +85 °C, 5–90 % RH (non‑condensing)
• Dimensions: 65 × 80 × 30 mm, Weight: 70 g

Integration with HW group Devices

The Expander 4xDI 1W‑UNI works seamlessly with HW group monitoring systems. In conjunction with devices like Poseidon2 or Ares, it provides real‑time monitoring of status signals from doors, detectors, or technical systems. Through the SensDesk.com IoT portal, alerts and status changes can be viewed in web browsers or mobile apps (Android/iOS).

Via SNMP or HTTP queries, input states can be directly integrated into network management systems. The HWg‑PDMS software also allows event logging, analysis, and export to Microsoft Excel.

Robust Design and Easy Installation

The compact housing of the Expander 4xDI 1W‑UNI (65 × 80 × 30 mm) is suitable for rack, wall, or cabinet installation. The optional industrial version offers a reinforced metal housing, ideal for harsh industrial environments. A 3 m RJ11 cable is included for immediate setup.

Installation and Configuration

Installation steps:

1. Connect the Expander via the included RJ11 cable to the 1‑Wire UNI port of your main device (Poseidon2 or Ares).
2. Connect up to four dry contacts to inputs IN1–IN4.
3. If more than two expanders are used, supply power from an external 5 V adapter.
4. Configure input conditions in the web interface of the main device to set alarm thresholds.
5. Alerts can be sent via email, SMS, or SNMP‑trap depending on the monitoring system configuration.

Advantages at a Glance

• Simple expansion of digital input capacity
• Plug‑and‑play integration with Poseidon2 and Ares systems
• Supports multiple modules via daisy‑chaining
• Bus‑powered operation without a separate supply voltage
• Fully compatible with HWg‑PDMS and SensDesk IoT platforms
• Ideal for security, industrial, and building management applications

The HW group Expander 4xDI 1W‑UNI is the ideal solution for expanding digital inputs in monitoring and automation systems. Its compatibility with HW group devices such as Poseidon2 and Ares, support for potential‑free contacts, and simple bus integration make it an essential component of modern remote monitoring architectures. With robust construction, compact form factor, and plug‑and‑play installation, the Expander forms a reliable foundation for secure, scalable, and efficient environmental and security monitoring applications.