The **M2UDS-E2-R2** is a high-performance, plug-in type digital multi-unit transducer manufactured by **M-System**. It is designed to measure AC voltage and current inputs, converting them into standardized DC output signals. --- ## 1. Core Technical Specifications The model suffix `E2-R2` defines specific hardware configurations for power supply and output types. | Feature | Specification | | :--- | :--- | | **Model Type** | M2UDS (Multi-Unit Transducer) | | **Input** | AC Voltage / Current (True RMS) | | **Output (E2)** | 4 – 20 mA DC (Internal power) | | **Power Input (R2)** | 11 – 27 V DC | | **Accuracy** | ±0.3% (at 23°C) | | **Response Time** | ≤ 0.5 seconds (0 – 90%) | | **Isolation** | Input to output to power to ground | --- ## 2. Key Electronic Components & Design ### A. Signal Conditioning Circuitry The device utilizes **True RMS (Root Mean Square)** conversion. This is critical because it allows the transducer to accurately measure distorted waveforms caused by harmonic noise or non-linear loads (like VFDs), which standard mean-rectifying transducers cannot do. ### B. Microprocessor Control The "Digital" aspect of the M2UDS involves an onboard microcontroller that performs: * **A/D Conversion:** Converts analog AC signals into high-resolution digital data. * **Linearization:** Corrects any non-linearities in the input signal. * **Calibration:** Factory-set parameters are stored in non-volatile memory to ensure long-term stability without manual trimmers. ### C. Isolation Barrier To protect sensitive PLC/DCS equipment, the M2UDS-E2-R2 features high-grade isolation (typically up to 2000V AC). * **Optical Isolation:** Used for signal transmission across the barrier. * **Transformer Isolation:** Used for the DC-to-DC converter to isolate the power supply. --- ## 3. Terminal Configuration The device uses a 10-pin base socket. Below is a general representation of the electronic connections: | Terminal No. | Function | Description | | :--- | :--- | :--- | | **1** | Output (+) | 4-20mA Signal | | **2** | Output (-) | Common | | **4** | Input (U) | Voltage or Current Input | | **5** | Input (V) | Voltage or Current Input | | **9** | Power (L+) | 11-27V DC Positive | | **10** | Power (N-) | 11-27V DC Negative | --- ## 4. Operational Indicators The front panel typically includes: * **Power LED:** Indicates the internal DC-DC converter is functioning. * **Calibration Adjustments:** While digital, it often features fine-tuning potentiometers for "Zero" and "Span" to match specific field requirements.