The **M2UDS-C3-R/N** is a specific model of an **Ultra-Slim Digital Panel Meter** manufactured by **M-System** (now part of MG CO., LTD). It is designed to measure and display DC voltage or current signals in an extremely compact form factor. Below is a breakdown of its electronic specifications and technical characteristics. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Input Signal** | DC Voltage or DC Current (Variable depending on setup) | | **Power Input (R)** | 24V DC (Standard for the 'R' designation) | | **Display** | 3.5 digit red LED (Maximum display 1999) | | **Mounting** | Ultra-slim surface mount (requires only a small hole) | | **Output (N)** | No Alarms (Standard indication-only model) | | **Accuracy** | ±0.1% rdg ±1 digit | --- ### 2. Part Number Breakdown Understanding the suffix codes is essential for identifying the specific electronics inside: * **M2UDS**: Series name (Ultra-slim Digital Panel Meter). * **C3**: Indicates the display type (3.5 digit LED, approximately 10mm character height). * **R**: Power Input code. **R** usually denotes **24V DC** power supply. * **N**: Output code. **N** indicates **None** (No alarm outputs/relays). --- ### 3. Electronic Components & Internal Design The M2UDS-C3 utilizes several core electronic subsystems to function: #### A. Signal Conditioning Circuitry This section uses high-precision resistors and operational amplifiers (Op-Amps) to scale the input signal (e.g., 4-20mA or 0-10V) down to a level that the internal Analog-to-Digital Converter (ADC) can process. #### B. Analog-to-Digital Converter (ADC) The "brain" of the measurement is typically a **Dual-Slope Integration ADC**. This method is preferred in industrial meters because it provides excellent rejection of 50/60Hz line noise, ensuring a stable display reading even in electrically noisy environments. #### C. LED Driver & Display The 3.5-digit red LED display is driven by a multiplexed driver circuit. This reduces power consumption and the number of traces required on the compact PCB. * **"3.5 Digit"** means the first digit can only be '1' or blank, while the other three can be 0-9. #### D. Power Isolation Despite its slim profile, these units often include basic filtering and protection circuits to handle voltage spikes common in industrial 24V DC loops. --- ### 4. Connection Diagram (General) Typical wiring for the M2UDS series involves 4 to 5 terminals: ```text Terminal No. | Function -------------|------------------ 1 | + Input (Signal) 2 | - Input (Signal) 3 | + Power (24V DC) 4 | - Power (0V) 5 | NC (No Connection) ``` ---