The **DL8-B-R** is a specific type of Web Data Logger manufactured by **M-System** (now MG CO., LTD). It serves as a remote monitoring unit that collects data from field devices and transmits it via Ethernet. Below is an explanation of its electronic components, specifications, and functional architecture. --- ### 1. Key Technical Specifications The "DL8-B-R" model name breaks down into specific hardware configurations: * **DL8:** Web Data Logger Series. * **B:** Type B (Supports Web browser views and FTP). * **R:** Power input (24V DC). | Feature | Specification | | :--- | :--- | | **Power Input** | 24V DC (±10%) | | **Communication** | Ethernet 100BASE-TX / 10BASE-T | | **Internal Storage** | SD Card Slot (for data logging storage) | | **Protocol Support** | Modbus/TCP, HTTP, FTP, SMTP, SNMP | | **Input/Output** | Expandable via R8 series I/O modules | --- ### 2. Electronic Parts & Components The device is composed of several critical internal and external hardware sections: #### A. Processing Unit & Memory * **Microprocessor:** An industrial-grade CPU that handles the TCP/IP stack and runs the embedded Web Server. * **SD Card Slot:** Crucial for non-volatile storage. It stores CSV log files and the user-defined HTML/CGI files for the web interface. * **RAM/Flash:** Internal memory used for buffering data before writing to the SD card. #### B. Connectivity Ports * **RJ-45 Ethernet Port:** The primary interface for network communication. It includes built-in isolation transformers to protect the internal circuitry from surges. * **Side Connector:** A proprietary bus interface used to connect **R8 series remote I/O modules** (Analog inputs, Pulse inputs, Discrete I/Os). #### C. Power Supply Circuitry * **DC-DC Converter:** Converts the 24V DC input into lower voltages (3.3V or 5V) required by the logic circuits. * **Protection:** Includes polarity protection and overcurrent protection (fuses) to prevent damage during installation. #### D. Indicators (LEDs) The front panel contains diagnostic LEDs: * **PWR:** Indicates power status. * **RUN:** Indicates the CPU is operating normally. * **ERR:** Lights up during system or hardware failures. * **SD:** Indicates SD card access or status. * **LNK/ACT:** Ethernet link and activity status. --- ### 3. Functional Architecture The DL8-B-R acts as a "Gateway" between the physical electrical signals and the digital network. 1. **Signal Acquisition:** It polls data from connected R8 I/O modules via the internal bus. 2. **Processing:** It scales raw electrical values (e.g., 4-20mA) into engineering units (e.g., Temperature, Pressure). 3. **Data Logging:** It saves these values to the SD card at specific intervals. 4. **Web Hosting:** It serves HTML pages so users can view real-time data on a smartphone or PC without specialized software. --- ### 4. Wiring Diagram Overview (Simplified) | Terminal | Function | Description | | :--- | :--- | :--- | | **U1 / U2** | 24V DC Power | Power supply connection (Polarity sensitive). | | **FE** | Functional Earth | Grounding for noise reduction. | | **RJ-45** | LAN | Connection to Hub, Router, or PC. |