The **M2REB-SAC-R/N** is a specific model of an **M2 series Rotary Encoder** manufactured by **Nemicon**. These devices are precision electromechanical components used to convert the angular position or motion of a shaft into analog or digital electrical signals. --- ## 1. Technical Specifications Overview The model name follows a specific nomenclature that defines its electronic and physical characteristics: | Feature | Specification | Description | | :--- | :--- | :--- | | **Series** | M2 | Miniature series (compact form factor) | | **Output Type** | Incremental | Provides pulses corresponding to change in position | | **Voltage** | 5V - 24V DC | Common operating range for industrial PLC/Microcontrollers | | **Output Phase** | A, B, Z | Standard quadrature (A/B) plus an Index pulse (Z) | | **Mounting** | REB | Usually refers to the bush/shaft mounting style | | **Signal Logic** | R/N | Refers to Output Circuitry (NPN Open Collector or Line Driver) | --- ## 2. Key Electronic Components The internal electronics of the M2REB series typically consist of three functional blocks: ### A. Optical Sensing Assembly * **LED Emitter:** A high-intensity infrared light source. * **Code Disk:** A rotating disk with precise slits that break the light beam. * **Photodetector Array:** A series of photodiodes that receive the pulsed light and convert it into low-level electrical current. ### B. Signal Processing Circuitry * **Schmitt Trigger:** An internal circuit that cleans up the raw analog signal from the photodiodes, converting them into crisp "square waves" to prevent false triggering from noise. * **Quadrature Logic:** Generates two signals (Phase A and Phase B) offset by 90°. This allows the controller to determine **direction** (clockwise vs. counter-clockwise). ### C. Output Stage (The "R/N" Designation) This part defines how the encoder talks to your controller: * **N (NPN Open Collector):** Acts like a switch to ground. Requires a pull-up resistor. Ideal for interfacing with different voltage levels. * **Line Driver (RS-422):** Used for long-distance cable runs. It provides differential signals (A and A-not) to cancel out electromagnetic interference (EMI). --- ## 3. Wiring Configuration Standard wiring for this Nemicon series usually follows this color convention (always verify with the specific datasheet provided with the unit): | Color | Function | Description | | :--- | :--- | :--- | | **Red** | Vcc | Main Power Supply (+) | | **Black** | GND | 0V / Common (-) | | **White** | Signal A | Main pulse count | | **Green** | Signal B | Directional pulse (90° offset) | | **Yellow** | Signal Z | Index/Home pulse (once per revolution) | | **Shield** | F.G. | Frame Ground (Noise protection) | --- ## 4. Applications Because of the "REB" miniature design, these are commonly found in: * **Medical Equipment:** Precision positioning in scanning beds. * **Robotics:** Joint angle feedback for small robotic arms. * **Office Automation:** Paper feed synchronization in high-end printers/copiers. * **Factory Automation:** Small conveyor speed monitoring.