The **M2VT-1C-R2** is a high-performance **Thermocouple Transmitter** manufactured by **M-System**. It is part of the M2-UNIT series, designed to convert a signal from a thermocouple sensor into a standard industrial DC output (like 4-20mA or 0-10V). --- ### 1. Technical Specifications Below are the primary electronic characteristics of the device: | Feature | Specification | | :--- | :--- | | **Input Type** | Thermocouple (K, E, J, T, B, R, S, C, N, U, L, P) | | **Output Type** | Single DC Output (Configurable via internal switches) | | **Power Input** | 100 – 240V AC | | **Accuracy** | ±0.1% of span | | **Isolation** | 4-way isolation (Input to Output to Power to Ground) | | **Response Time** | ≤ 0.5 seconds (0 – 90%) | | **Mounting** | DIN Rail Mounting (M2 series socket) | --- ### 2. Core Electronic Components & Functions #### A. Signal Conditioning Circuitry The device contains high-precision operational amplifiers that amplify the millivolt (mV) signal generated by the thermocouple. Because thermocouple signals are non-linear, the M2VT includes **linearization circuitry** to ensure the output is proportional to the temperature. #### B. Cold Junction Compensation (CJC) Thermocouples measure the temperature difference between the "hot end" and the "cold end." The M2VT includes an internal temperature sensor (thermistor or RTD) at the terminal block to compensate for the ambient temperature at the connection point, ensuring accurate absolute temperature readings. #### C. Galvanic Isolation One of the most critical electronic features is the **2000V AC isolation**. It uses opto-isolators or magnetic transformers to separate the input, output, and power circuits. This protects the control system (PLC/DCS) from ground loops and high-voltage surges. #### D. Burnout Protection The electronic logic is designed to detect a broken thermocouple wire. In the event of a "burnout," the transmitter can be configured to drive the output signal **Upscale** (e.g., >20mA) or **Downscale** (e.g., <4mA) to alert the operator. --- ### 3. Connection Diagram Overview Typical wiring involves the following terminal assignments: 1. **Terminals 1 & 2:** Power Input (AC). 2. **Terminals 4 & 5:** Thermocouple Input (Positive/Negative). 3. **Terminals 7 & 8:** DC Output Signal. --- ### 4. Configuration Switches Inside the housing, there are **DIP switches** and **Rotary switches** used to: * Select the Thermocouple type (e.g., Type K vs. Type J). * Set the temperature range (Zero and Span adjustments). * Choose the Output signal range (e.g., 4-20mA or 1-5V).