The **M2RTS-R-A3-P** is a high-performance **Resistance Temperature Detector (RTD) Transmitter** belonging to the M2 Series (Plug-in type) manufactured by **M-System**. It is designed to convert signals from an RTD into a standard DC output signal (current or voltage). --- ## 1. Technical Specifications The following table outlines the primary electronic and functional characteristics of the device: | Feature | Specification Details | | :--- | :--- | | **Input Type** | RTD (Pt 100, JPt 100, etc.) | | **Output Type** | DC Voltage or Current (Fixed based on suffix) | | **Power Input (A3)** | 100V – 120V AC (50/60 Hz) | | **Isolation** | 3-way isolation (Input to Output to Power) | | **Connection** | 11-pin plug-in base | | **Linearization** | Standard electronic linearization circuit | | **Burnout Protection** | Standard (Upscale burnout) | --- ## 2. Breakdown of the Model Suffix (A3-P) The alphanumeric suffix defines the specific electronic configuration of the unit: * **R (Output):** Typically signifies a specific output range (e.g., 4–20mA DC or 1–5V DC). * **A3 (Power):** Indicates the power supply requirement. `A3` specifically refers to **100V – 120V AC**. * **P (Option):** Often refers to a specific performance enhancement or a custom factory calibration setting. --- ## 3. Key Electronic Components & Functions ### A. Signal Conditioning Circuit The core of the M2RTS is a precision bridge circuit. It measures the resistance change of the RTD (usually Pt100) and converts it into a voltage. Because RTD resistance is not perfectly linear with temperature, the device includes an **Electronic Linearizer** to ensure the output signal is proportional to the temperature. ### B. Galvanic Isolation This device features **3-port isolation**. Electronic components like optoisolators or transformers are used to separate: 1. The sensitive RTD input. 2. The analog output signal. 3. The AC power supply. *This prevents ground loops and protects the control system (PLC/DCS) from high-voltage surges.* ### C. Burnout Detection In the event of a sensor wire breakage, the electronic circuit is designed to drive the output signal to a maximum (Upscale) or minimum (Downscale) value. This serves as a safety trigger for the connected controller to identify a sensor failure. --- ## 4. Wiring Diagram Overview The unit uses an 11-pin base. Typical pin assignments for an RTD transmitter include: | Pin Number | Function | | :--- | :--- | | **1 & 11** | Power Supply (L & N) | | **4, 5, 6** | RTD Input (3-wire system) | | **9 (+), 10 (-)** | DC Output Signal |