The **M2UDS-4WA-R2/N** appears to be a specific model variant of an **M2UDS series Ultra-Slim Digital Panel Meter**, likely manufactured by **M-System** (now MG CO., LTD.). These devices are designed to measure and display analog signals (like voltage or current) in a compact, panel-mounted form factor. --- ## 1. Core Technical Specifications The model string typically breaks down into specific electronic characteristics: | Component | Specification | Description | | :--- | :--- | :--- | | **Series** | M2UDS | Ultra-slim digital panel meter (often 1/32 DIN size). | | **Input Type (4W)** | 4-20mA DC | Standard industrial current loop input. | | **Power Input (A)** | 100–240V AC | Universal AC power supply compatibility. | | **Output/Relay (R2)** | 2 Relay Outputs | Dual alarm/control outputs (typically SPST or SPDT). | | **Special (N)** | No Option | Standard configuration without specific custom coatings or labels. | --- ## 2. Key Electronic Features ### A. Display and Scaling * **Digital Readout:** Usually features a 4-digit LED display. * **Scaling:** The 4-20mA input signal can be electronically scaled to represent physical units (e.g., 0-100% or 0-500 Liters). * **Decimal Point:** User-configurable via front-panel buttons or internal jumpers. ### B. Input/Output Isolation * **Galvanic Isolation:** The device provides isolation between the input signal, the power supply, and the relay outputs. This prevents ground loops and protects sensitive PLC/DCS equipment. * **Impedance:** For the 4-20mA input, the internal resistance is typically low (around 50-100 $\Omega$) to minimize voltage drop in the loop. ### C. Alarm Functions (R2) * **High/Low Setpoints:** The two relays can be programmed as High-High, High-Low, or Low-Low alarms. * **Hysteresis:** Electronic dead-band settings to prevent "chattering" of the relays when the signal fluctuates near the setpoint. --- ## 3. Physical & Connection Layout As an ultra-slim model, the electronics are densely packed into a shallow housing. 1. **Terminals:** Usually screw compression terminals located at the rear. 2. **Mounting:** Designed for standard panel cutouts with a secure plastic or metal clip. 3. **Front Panel:** Membrane switches for "Mode," "Up," and "Down" to navigate the electronic configuration menu. --- ## 4. Typical Applications * **Process Monitoring:** Displaying pressure, temperature, or flow from a transmitter. * **Safety Interlocks:** Using the R2 relays to shut down a pump if a tank level exceeds a certain 4-20mA threshold. * **Remote Monitoring:** Converting a sensor signal into a readable local display for operators on a factory floor.