The **MLG-2 WebChecker (MLG-2B)** by SICK is a high-resolution measuring automation light grid. It is specifically designed for complex applications such as web edge measurement, width monitoring, and object positioning. Below is a breakdown of the electronic components and technical specifications for the **MLG-2B-R (Receiver)** and **MLG-2B-Q (Standard I/O variants)**. --- ## 1. Core Electronic Components The system consists of two primary electronic bars that work in synchronization: | Component | Role | Description | | :--- | :--- | :--- | | **Emitter (Sender)** | Light Source | Contains a vertical array of LEDs (Infrared light, 850 nm) that pulse in a specific sequence. | | **Receiver (MLG-2B-R)** | Sensor Array | Contains the phototransistors and the **Processing Unit**. It evaluates which beams are broken and calculates the measurement values. | | **ASIC/Processor** | Logic Engine | Integrated into the receiver to handle high-speed signal processing (response times as low as 3.5 ms). | --- ## 2. Technical Electronic Specifications The MLG-2B series utilizes a 24V DC infrastructure and provides multiple interface options for data output. ### Electrical Data * **Supply Voltage:** 18 V ... 30 V DC. * **Power Consumption:** Varies by beam count (typically < 200 mA). * **Output Load:** Max. 100 mA. * **Circuit Protection:** Output overcurrent protection, reverse polarity protection, and interference pulse suppression. ### Signal Interfaces The "Q" and "R" designations often refer to the output configuration: * **Push-Pull (Q):** Most variants feature push-pull outputs that can act as either PNP or NPN. * **Analog Outputs:** Some models provide 4 mA ... 20 mA for real-time width measurement. * **Communication:** Supports **IO-Link (V1.1)** for parameterization and process data transmission. --- ## 3. Wiring and Pin Configuration (M12 Connector) The MLG-2B typically uses an M12, 5-pin or 8-pin connector. Below is a standard 5-pin electronic pinout: | Pin | Color | Signal | Description | | :--- | :--- | :--- | :--- | | 1 | Brown | L+ | +24 V DC Supply | | 2 | White | Q2 / In1 | Digital Output 2 or Teach-in Input | | 3 | Blue | M | 0 V (Ground) | | 4 | Black | Q1 / C | Digital Output 1 / IO-Link Communication | | 5 | Gray | Q3 | Digital Output 3 | --- ## 4. Measuring Electronics Features The MLG-2B "WebChecker" version includes specific electronic logic functions: 1. **Beam Spacing:** Available in 2.5 mm, 5 mm, 10 mm, etc. 2. **Cross-Beam Logic:** The electronics can calculate diagonal beams to increase resolution. 3. **Automatic Threshold:** The receiver adjusts its sensitivity electronically to compensate for dust or ambient light. 4. **Synchronisation:** Optical synchronization means no physical cable is required between the sender and receiver bars. ---