The **EX77424-R3RWR** is a specialized, industrial-grade Managed Ethernet Switch produced by **EtherWAN**. It is designed for harsh environments, specifically targeting power substation and railway applications. --- ### 1. Core Technical Specifications The device is a high-performance networking component. Below is a breakdown of its primary electronic hardware features: | Feature | Specification Details | | :--- | :--- | | **Port Configuration** | 24-port 10/100BASE-TX + 4-port Gigabit (SFP or Copper) | | **Switching Capacity** | High-speed backplane designed for wire-speed Layer 2 management | | **Mounting** | 1U 19" Rack-mount | | **Management** | Managed (SNMP, Web, Telnet, CLI) | | **Redundancy** | Support for Alpha-Ring, RSTP, MSTP, and STP | --- ### 2. Key Electronic & Hardware Characteristics #### A. Power Supply Architecture (`R3RWR`) The suffix in the model number typically refers to the power configuration: * **Redundant Inputs:** Features dual power inputs to ensure zero downtime. * **Voltage Range:** Often supports wide-range DC (e.g., 18-75VDC) or AC/DC universal inputs, depending on the specific sub-revision. * **Isolation:** High-level electromagnetic isolation to protect internal circuitry from power surges common in industrial grids. #### B. Industrial Hardening Unlike commercial switches, the EX77424 series uses high-grade electronic components capable of: * **Temperature Resilience:** Operating ranges from **-40°C to 75°C** (-40°F to 167°F). * **No Fans:** Uses passive cooling (heatsinks) to prevent mechanical failure and dust intake. * **EMI/EMC Protection:** Certified for **IEC 61850-3** and **IEEE 1613**, meaning it can operate near high-voltage transformers without signal interference. #### C. Interface Electronics * **SFP Slots:** The Gigabit ports utilize Small Form-factor Pluggable (SFP) transceiver modules, allowing for fiber optic connections over long distances. * **MDI/MDIX:** Auto-crossover electronic sensing for all copper ports. * **Relay Output:** Includes a physical "Fault" relay (dry contact) that triggers an external alarm if power fails or a port goes down. --- ### 3. Standards and Compliance The electronics are tested against rigorous international standards: 1. **Safety:** UL 60950-1, EN 60950-1. 2. **Railway:** EN 50121-4 (Trackside signaling interference protection). 3. **Shock/Vibration:** IEC 60068-2-27/6/32. ---