The **FLM-DE-R** is a specialized electronic component, typically identified as a **Bus-Powered Field Link Module** (Digital Input/Output) within industrial fire alarm and security systems (specifically the Bosch LSN network). It serves as an interface between a fire panel and external devices. --- ### 1. Technical Specifications Below are the primary electronic characteristics and ratings for the module: | Parameter | Specification | | :--- | :--- | | **Input Voltage** | 15 V DC to 33 V DC (via LSN bus) | | **Current Consumption** | Max 0.6 mA | | **Relay Contact Rating** | 1 A at 30 V DC | | **Protection Class** | IP 30 (standard enclosure) | | **Operating Temperature** | -20 °C to +50 °C | | **Addressing** | Via rotary switches or software | --- ### 2. Core Electronic Components & Functions The module architecture consists of three main functional blocks: #### A. The LSN Bus Interface The "Heart" of the module is the **LSN (Local Security Network) Controller IC**. - **Communication:** It uses a proprietary protocol to talk to the fire panel. - **Power Management:** It extracts power directly from the data loop, meaning it does not require an external power supply for basic operation. - **Isolation:** It features integrated isolators that ensure the rest of the loop continues to function if a short circuit occurs at this specific node. #### B. Relay Outputs (The "R" in DE-R) The "R" designation signifies a **Relay** output. - **Electronic Switch:** It uses a dry-contact relay that allows the fire panel to trigger external hardware (such as door closers, fans, or sirens). - **Feedback:** The module monitors the state of the relay to ensure it has successfully switched. #### C. Input Monitoring Circuitry The module includes digital inputs designed to monitor "normally open" or "normally closed" contacts. - **End-of-Line (EOL) Resistors:** The electronic circuit uses resistors to monitor the line for three states: *Idle, Triggered,* and *Fault (Wire Break/Short).* - **Debounce Logic:** Internal filtering prevents false alarms caused by electrical noise or "contact bounce." --- ### 3. Connection Terminals The electronic wiring is generally distributed across the following terminal blocks: 1. **LSN In/Out:** Connects to the main data loop from the fire panel. 2. **Input Terminals:** For monitoring external sensors (e.g., flow switches). 3. **Relay Terminals:** COM (Common), NO (Normally Open), and NC (Normally Closed) contacts. --- ### 4. Rotary Switch Addressing On the PCB (Printed Circuit Board), you will find **Rotary Switches**. These allow the technician to manually set the electronic address (001–254) for the module so the fire panel can identify its specific location in the building.