The **M2RTS-R-2G-R2/Q** is a high-precision, industrial-grade RTD (Resistance Temperature Detector) transmitter, typically manufactured by **M-System**. This device is designed to convert temperature signals from an RTD sensor into a standard analog output signal. --- ## 1. Core Specifications and Identification The alphanumeric code identifies specific electronic characteristics of the unit: | Component | Meaning | Description | | :--- | :--- | :--- | | **M2RTS** | Series Name | Mini-M series RTD transmitter. | | **R** | Power Input | Indicates 24V DC power requirement. | | **2G** | Input Type | Pt 100 (ITS-90) RTD input. | | **R2** | Output Type | 4 – 20 mA DC (Current output). | | **Q** | Option | Special specifications or customized settings (e.g., specific scaling). | --- ## 2. Key Electronic Components & Internal Functions The internal circuitry of the M2RTS is divided into four main stages: ### A. Input Stage (Signal Conditioning) * **Constant Current Source:** The device sends a small, precise DC current through the RTD sensor to measure voltage drop. * **Burnout Protection:** Includes specialized resistors and logic to detect if the sensor wire is broken, typically forcing the output to a safe high or low limit. * **Three-wire Compensation:** Circuits designed to cancel out the lead-wire resistance of the RTD sensor to ensure accuracy over long distances. ### B. Isolation Barrier * **Galvanic Isolation:** This is a critical feature. It uses opto-isolators or transformers to provide **three-way isolation** (Input to Output to Power). * **Benefit:** Protects the PLC/DCS from high-voltage surges and eliminates ground loops. ### C. Processing Stage * **Linearization Circuit:** Since RTD resistance is not perfectly linear with temperature, internal analog or digital circuits "straighten" the signal to ensure the 4-20mA output matches the temperature scale exactly. * **Zero/Span Adjustments:** Potentiometers (or digital trims) located on the front panel allow for manual calibration. ### D. Output Stage * **Current Loop Driver:** A high-precision operational amplifier (Op-Amp) and transistor stage that maintains the 4-20mA current regardless of the load resistance (up to a specific limit, usually 550Ω). --- ## 3. Technical Parameters | Parameter | Value | | :--- | :--- | | **Input Signal** | Pt 100 (3-wire) | | **Supply Voltage** | 24V DC (±10%) | | **Current Consumption** | Approx. 60 mA | | **Isolation Resistance** | 100 MΩ or more at 500V DC | | **Dielectric Strength** | 2000V AC @ 1 minute | | **Response Time** | ≤ 0.5 seconds (0 to 90%) | --- ## 4. Wiring Diagram (Conceptual) The following represents the typical terminal assignment for this module: ```text [ Power ] [ Input ] [ Output ] 1 (+) 4 (A) 9 (+) 2 (-) 5 (B) 10 (-) 6 (B) ```