The **M2RT-55-R2/CE** is a high-precision, industrial-grade temperature transmitter/converter, typically part of the M2 series manufactured by companies like **M-System**. It is designed to convert signals from a Resistance Temperature Detector (RTD) into a standard DC output signal. --- ### 1. Core Technical Specifications The "R2" designation often refers to the power input and output configuration, while the "CE" indicates compliance with European safety and electromagnetic standards. | Feature | Specification | | :--- | :--- | | **Input Type** | 2 or 3-wire RTD (e.g., Pt 100, Pt 50, JPt 100) | | **Output Signal** | 4 – 20 mA DC (Standard Loop) | | **Power Input** | 24V DC (typical for R2 suffix) | | **Isolation** | 3-way isolation (Input to Output to Power) | | **Accuracy** | ±0.1% of span | | **Mounting** | DIN rail mounting | --- ### 2. Key Electronic Components & Design The internal circuitry is engineered for stability in electrically noisy industrial environments. * **Signal Conditioning Front-End:** Contains a constant current source to excite the RTD. It includes linearization circuitry to compensate for the non-linear resistance-temperature curve of platinum sensors. * **Galvanic Isolation:** Uses optical or magnetic isolators to separate the input, output, and power circuits. This prevents ground loops and protects the control system from high-voltage surges on the sensor side. * **Burnout Protection:** The electronics include a "Burnout" feature. If the RTD wire snaps, the output will automatically go to a pre-set state (Upper limit $\geq$ 20.8 mA or Lower limit $\leq$ 3.8 mA) to alert the PLC/DCS of a sensor failure. * **Zero and Span Adjustments:** Located on the front panel, these potentiometers allow for fine-tuning the electronic calibration without removing the unit from the rail. --- ### 3. Connection Diagram Logic The device typically uses a plug-in base for easy maintenance. ```text Terminal Function ---------------------- 1 - 2 Output (+) / (-) 4 - 5 Power Input (24V DC) 11-12-13 RTD Input (A, B, b) ``` --- ### 4. CE Compliance Features The **CE** mark ensures the internal electronic parts meet specific requirements: * **EN 61000-6-4:** Electromagnetic emissions (Industrial). * **EN 61000-6-2:** Electromagnetic immunity (Industrial). * **Low Voltage Directive:** Ensures the internal insulation distances are safe for human operators.