The **M2RTS-R-CC-R** is a specific model within the M2 Series of **Signal Conditioners** manufactured by **M-System** (now part of MG CO., LTD). This device is primarily used in industrial automation to convert, isolate, and transmit temperature signals from Resistance Temperature Detectors (RTDs). ### 1. Key Technical Specifications The model code provides specific information about the electronic configuration and I/O types: | Component Code | Description | Specifications | | :--- | :--- | :--- | | **M2RTS** | Model Name | RTD Transmitter (Plug-in base) | | **-R** | Input Signal | RTD (Pt 100, JPt 100, etc.) | | **-CC** | Output Signal | Dual Output: 4 – 20 mA DC (Current Loop) | | **-R** | Power Input | 24V DC | --- ### 2. Electronic Components and Functionality The internal circuitry of the M2RTS-R-CC-R is designed for high precision and noise rejection in harsh industrial environments. #### A. Input Circuit (RTD Interface) * **Constant Current Source:** To measure the resistance of an RTD (like a Pt100), the device provides a small, stable constant current to avoid self-heating errors. * **3-Wire Compensation:** Includes circuitry to compensate for the lead-wire resistance, ensuring that the length of the cable between the sensor and the transmitter doesn't skew the temperature reading. * **Burnout Protection:** An electronic "Upscale" or "Downscale" circuit that forces the output to a specific limit if the RTD sensor wire breaks. #### B. Signal Processing & Isolation * **Galvanic Isolation:** This unit features **three-way isolation** (Input to Output to Power). This is achieved using opto-isolators or magnetic transformers to prevent ground loops and protect sensitive PLC/DCS equipment from high-voltage surges. * **Linearization:** Since RTD resistance changes are not perfectly linear with temperature, the internal microprocessor or analog shaping circuit applies a linearization curve to ensure the output is proportional to the actual temperature. #### C. Output Stage * **Dual Output (-CC):** The electronic board splits the processed signal into two independent 4–20 mA current loops. This allows one signal to go to a local display/controller and the other to a central SCADA system. * **Zero/Span Adjustments:** Located on the front panel, these potentiometers allow for fine-tuning the analog electronics to calibrate the 0% and 100% points. --- ### 3. Connection Diagram (General) The electronics are housed in a plug-in socket for easy maintenance. ```text Terminal | Function ---------|------------------------- 1 & 2 | Output 1 (4-20mA + / -) 3 & 4 | Output 2 (4-20mA + / -) 5, 6, 7 | RTD Input (A, B, B') 8 & 9 | Power Supply (24V DC) ```