The **M2TT-45-R2/CE** is a high-precision, industrial-grade **Thermo-Transmitter (Temperature Transmitter)** typically used in automation and process control systems. It is designed to convert signals from temperature sensors (like Thermocouples or RTDs) into a stable, linearized analog output. --- ### 1. Core Technical Specifications The "R2" designation often refers to the output signal type, while "CE" denotes compliance with European safety and environmental standards. | Feature | Description | | :--- | :--- | | **Input Type** | Thermocouple (typically Type K, J, T, etc.) or RTD (Pt100) | | **Output Signal** | 4–20 mA DC (Current Loop) | | **Power Supply** | 24V DC (Standard Loop Powered) | | **Accuracy** | ±0.1% to ±0.2% of Full Scale | | **Response Time** | < 500ms | | **Mounting** | DIN Rail Mount (Standard 35mm) | --- ### 2. Key Electronic Components & Functions Internally, the M2TT-45-R2/CE consists of several critical electronic stages: 1. **Signal Conditioning Input:** Uses a high-impedance amplifier to pick up millivolt signals from thermocouples without loading the sensor. 2. **Cold Junction Compensation (CJC):** For thermocouple models, an internal thermistor measures the temperature at the connection terminals to compensate for the ambient temperature, ensuring the reading is accurate relative to the "hot junction." 3. **Linearization Circuit:** Since temperature sensor outputs are non-linear, the internal electronics use a curve-fitting algorithm (via an MCU or analog shaping) to ensure the 4-20mA output is perfectly proportional to the temperature. 4. **Galvanic Isolation:** The "M2" series usually features 2-way or 3-way isolation between input, output, and power. This prevents ground loops and protects the PLC/Controller from high-voltage surges on the sensor side. 5. **Output Driver:** A precision current source that maintains the 4-20mA loop even if the load resistance changes (within specified limits). --- ### 3. Wiring Configuration The device usually follows a standard industrial pinout for DIN-rail transmitters: ```mermaid graph LR A[Sensor Input] --> B(M2TT-45-R2/CE) B --> C[4-20mA Output to PLC] D[24V DC Power] --> B ``` * **Terminals 1 & 2:** Sensor Input (+ / -) * **Terminals 4 & 5:** Output Current Loop * **Terminals 7 & 8:** Power Supply (if not loop-powered) --- ### 4. Applications * **HVAC Systems:** Monitoring duct temperatures. * **Manufacturing:** Heat treatment furnaces and plastic injection molding. * **Data Acquisition:** Converting raw sensor data into a format readable by long-distance PLC cables without signal degradation. ---