The **M2VT-B1-R2** is a high-performance **Programmable Signal Conditioner** (often referred to as a transducer or isolator) manufactured by **M-System**. It is part of the Mini-M series and is designed to convert a DC input signal into a standard DC output signal while providing galvanic isolation. --- ## 1. Technical Specifications The model number **M2VT-B1-R2** breaks down into specific technical attributes: | Component Code | Meaning | Specifications | |:---|:---|:---| | **M2VT** | Model Series | Programmable Signal Conditioner (Microprocessor-based) | | **B** | Input Signal | DC Input (Configurable; Factory set to 1–5V DC) | | **1** | Output Signal | 4–20 mA DC | | **R2** | Power Supply | 11–27V DC | ### Key Electrical Characteristics * **Accuracy:** ±0.1% of span. * **Response Time:** $\leq$ 0.5 seconds (0 to 90%). * **Isolation:** 2000V AC @ 1 minute (Input to Output to Power to Ground). * **Insulation Resistance:** $\geq$ 100 M$\Omega$ with 500V DC. --- ## 2. Core Electronic Components & Architecture The internal circuitry of the M2VT-B1-R2 is built around several critical stages: ### A. Input Stage (A/D Conversion) The unit features a high-impedance input stage that accepts DC voltage or current. Because it is "programmable," the input signal is processed through an **Analog-to-Digital Converter (ADC)**. This allows the device to handle non-linear signals or apply square root extraction via software. ### B. Microprocessor Control Unlike simple analog isolators, the M2VT uses a **Microcontroller (MCU)**. This allows for: * **Zero/Span Adjustments:** Digital calibration without physical potentiometers. * **User Programming:** Parameters can be changed using a PC or a dedicated hand-held programmer. ### C. Galvanic Isolation (The Optical/Magnetic Barrier) To prevent ground loops and protect sensitive PLC/DCS inputs, the device employs **Three-way Isolation**: 1. **Input to Output** 2. **Input to Power** 3. **Output to Power** ### D. Output Stage (D/A Conversion) The processed digital signal is converted back to an analog 4–20mA current loop via a **Digital-to-Analog Converter (DAC)** and a constant-current drive circuit. --- ## 3. Wiring and Terminal Configuration The device is designed for DIN rail mounting with a plug-in base. | Terminal No. | Function | Description | |:---:|:---|:---| | 1 | Output (+) | 4–20 mA Current Output | | 2 | Output (-) | Common Return | | 3 | Input (+) | DC Voltage/Current Input | | 4 | Input (-) | Input Common | | 5 | Power (+) | 11–27V DC Supply | | 6 | Power (-) | 0V DC | --- ## 4. Maintenance and Programming The M2VT-B1-R2 features a front-facing jack for the **PU-2x** (Programming Unit) or a PC connection. This allows the user to: * Change the input range. * Enable/Disable linear characterization. * Check the current output value for troubleshooting.