The **FLM-4B-R/Q** refers to a specific type of Logic Monitor or Interface Module, commonly used in fire alarm systems (specifically the Bosch series). The "R" usually denotes a Relay function, while the "Q" refers to a specific form factor or configuration. Below is an explanation of its electronic components and technical characteristics. --- ### 1. General Technical Specifications These modules are designed to provide a dry-contact relay output for controlling external equipment like fire doors, elevators, or HVAC systems via a fire alarm control panel. | Specification | Details | | :--- | :--- | | **Input Voltage** | 15 V DC to 33 V DC (LSN loop power) | | **Current Consumption** | < 0.2 mA (Standby) | | **Contact Load** | Max. 2 A @ 30 V DC or 0.5 A @ 125 V AC | | **Interface** | LSN (Local Security Network) | | **Address Setting** | Rotary switches or Auto-addressing | --- ### 2. Key Electronic Components The internal circuitry of the FLM-4B-R/Q consists of several critical subsystems: #### A. Microcontroller & LSN Chip The brain of the unit is a low-power microcontroller paired with an **LSN (Local Security Network) Interface**. This allows the module to communicate with the main fire panel, report its status, and receive activation commands. #### B. Relay Mechanism * **Form C Contact:** The "R" module contains a physical electromagnetic relay. It usually provides a change-over contact (Common, Normally Open, Normally Closed). * **Isolation:** The relay provides galvanic isolation between the fire alarm loop and the high-voltage/high-current external equipment. #### C. Addressing Mechanism (Rotary Switches) The module typically features three rotary switches used to manually set the module's unique address on the loop (from 001 to 254). * **000:** Automatic addressing mode. * **CL:** Used for "Classic" LSN mode. #### D. Diagnostic LEDs A built-in LED (often red or bicolor) provides visual feedback: * **Flashing:** Normal polling/communication. * **Steady Light:** Relay is activated or an error state exists. --- ### 3. Wiring Configuration The module interfaces with the LSN loop via two main terminal sets: 1. **LSN In/Out:** Connections for the data/power loop from the fire panel. 2. **Relay Terminals:** * **C (Common)** * **NO (Normally Open)** * **NC (Normally Closed)** --- ### 4. Application Examples * **Elevator Recall:** Triggers the elevator to return to the ground floor during a fire. * **Fan Shutdown:** Disables HVAC fans to prevent smoke spread. * **Door Release:** Cuts power to magnetic door holders to close fire doors.