The **M2RTS-R-3A-R** is a specific model of an **RTD (Resistance Temperature Detector) Transmitter** within the M2 Series, manufactured by M-System. It is designed to convert signals from a temperature sensor (RTD) into a standard DC output signal. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Model Series** | M2RTS (Ultra-slim Signal Conditioner) | | **Input Type** | RTD (e.g., Pt 100, JPt 100, Cu 10) | | **Output Type** | 4 to 20 mA DC (denoted by code "A") | | **Power Input** | 24V DC (denoted by code "R") | | **Mounting** | DIN Rail Mounting | | **Construction** | Plug-in base structure | --- ### 2. Breakdown of the Model Code (M2RTS-R-3A-R) Understanding the alphanumeric suffix is critical for identifying the electronic behavior of the unit: * **M2RTS**: Base model for the RTD Transmitter. * **-R**: Power Input. Indicates the unit operates on **24V DC**. * **-3**: Input Signal. This typically refers to a **Pt 100 (ITS-90)** sensor. * **-A**: Output Signal. This signifies a **4 to 20 mA DC** current loop output. * **-R**: (Suffix) Usually indicates the **Burnout** direction or a specific option. In many M-System configurations, the final "R" indicates a **standard rack-mounted/plug-in** style or a specific high-resistance option. --- ### 3. Core Electronic Components & Functions The internal circuitry of the M2RTS-R-3A-R consists of several functional blocks: 1. **Input Bridge/Front End**: Excites the RTD sensor with a small, constant current to measure resistance changes without causing self-heating. 2. **Linearization Circuit**: RTDs are not perfectly linear. The internal electronics linearize the resistance-to-temperature curve to ensure the output is proportional to the actual temperature. 3. **Isolation Transformer**: Provides galvanic isolation between the input, output, and power supply. This prevents ground loops and protects sensitive PLC/DCS equipment. 4. **Zero/Span Adjustments**: Located on the front panel, these allow manual calibration to fine-tune the minimum (4mA) and maximum (20mA) points. 5. **Burnout Protection**: If the RTD wire breaks, the transmitter is programmed to drive the output signal either upscale (above 20mA) or downscale (below 4mA) to alert the control system of a sensor failure. --- ### 4. Connection Diagram (Simplified) ```mermaid graph LR A[RTD Sensor] -- 3-Wire Connection --> B(M2RTS Transmitter) C[24V DC Power] --> B B -- 4-20mA Signal --> D[PLC / Controller] ``` --- ### 5. Application Benefits * **Space Saving**: The ultra-slim design allows for high-density installation in control panels. * **Signal Integrity**: Converting a weak RTD resistance to a 4-20mA current loop allows for long-distance transmission without interference or voltage drops. * **Maintenance**: The plug-in socket base allows the electronic module to be replaced without disconnecting the field wiring. ---