The **FLM-FW0-R** is an electronic component primarily associated with **Bosch Security Systems**. It is a **Single-Action Manual Call Point (Red)** designed for use with Local SecurityNetwork (LSN) fire alarm systems. Below is a breakdown of its electronic specifications and functional characteristics. --- ### 1. Technical Specifications The device operates on the LSN (Local Security Network) bus, which provides both power and data communication. | Feature | Specification | | :--- | :--- | | **Operating Voltage** | 15 V DC to 33 V DC (LSN) | | **Current Consumption** | 0.26 mA (standby) | | **Communication Protocol** | LSN improved version | | **Protection Class** | IP 54 | | **Standard** | EN 54-11 | | **Housing Material** | ASA Plastic (Red, RAL 3001) | --- ### 2. Core Electronic Components The internal circuitry of the FLM-FW0-R consists of several key electronic layers: * **LSN Interface Chip:** A specialized integrated circuit (IC) that manages bidirectional communication with the fire alarm control panel. It handles addressing and status reporting. * **Trigger Mechanism:** A micro-switch or optical sensor (depending on the specific revision) that detects when the glass pane is broken or the reset element is pressed. * **LED Indicator:** A high-visibility red LED that illuminates when the device is triggered, providing visual confirmation that the alarm has been sent. * **Addressing Logic:** It features rotary switches or digital addressing capabilities, allowing the control panel to identify exactly which manual call point has been activated. --- ### 3. Functional Mechanism The electronics are designed for **fail-safe operation**: 1. **Polling:** The fire panel constantly "polls" the device via the LSN bus to ensure it is online. 2. **Triggering:** When the front pane is displaced, the internal switch changes state. 3. **Data Transmission:** The LSN chip immediately sends an interrupt signal to the panel, changing the device status from "Normal" to "Alarm." 4. **Integrated Isolator:** In the event of a short circuit on the LSN loop, integrated electronic isolators ensure that the rest of the loop remains functional. --- ### 4. Wiring and Installation The device typically uses a 4-wire LSN connection (In+/In- and Out+/Out-), allowing for "daisy-chain" or "loop" configurations. ```cpp // Schematic representation of LSN Loop Wiring [Panel] ---- (LSN +/–) ---- [FLM-FW0-R #1] ---- (LSN +/–) ---- [FLM-FW0-R #2] ```