The **M2UDS-K5-R2** is a specific model within the **M2 Series** of digital panel meters manufactured by **M-System** (now part of MG CO., LTD). This device is primarily used as a digital indicator with alarm outputs for industrial automation and process control. --- ### 1. Model Code Breakdown Understanding the specific nomenclature helps identify the electronic capabilities of this unit: | Code Segment | Description | Specific Detail | | :--- | :--- | :--- | | **M2UDS** | Base Model | Digital Indicator (4-digit LED) | | **K5** | Input Type | **DC Voltage/Current** (Universal Input) | | **R** | Output Type | **Relay Contact** (Dual Alarms) | | **2** | Power Supply | **24V DC** | --- ### 2. Key Electronic Components & Functions #### A. Input Stage (The "K5" Configuration) The input circuitry is designed to handle high-precision analog signals. * **Voltage Inputs:** Typically ranges from 0–10V, 1–5V, or ±10V DC. * **Current Inputs:** Typically 4–20mA or 0–20mA (requires an external or internal shunt resistor). * **A/D Converter:** High-resolution Analog-to-Digital converter to ensure process accuracy. #### B. Display & Processing * **LED Display:** A 4-digit, red LED display (character height approx. 8mm). * **Microcontroller:** Manages the scaling of the raw analog input into engineering units (e.g., PSI, °C, Liters) and controls the alarm logic. #### C. Alarm Outputs (The "R" Configuration) * **Relay Type:** Dual (2) Form A relay contacts. * **Capacity:** Rated for approximately 250V AC @ 0.5A or 30V DC @ 0.5A (resistive load). * **Logic:** Includes programmable deadband (hysteresis) and ON-delay timers to prevent "chattering" of the relays. #### D. Power Supply (The "2" Configuration) * **Operating Voltage:** 24V DC (±10%). * **Isolation:** The electronics feature 3-way isolation between the **Input**, **Output**, and **Power Supply** terminals. This prevents ground loops and protects the internal circuitry from surges. --- ### 3. Technical Specifications Summary | Feature | Specification | | :--- | :--- | | **Display Range** | -1999 to 9999 | | **Accuracy** | ±0.1% of span ±1 digit | | **Sampling Rate** | Approx. 100 milliseconds | | **Insulation Resistance** | 100 MΩ or more with 500V DC | | **Dielectric Strength** | 2000V AC @ 1 minute (Input to Output to Power) | | **Housing Material** | Flame-resistant resin (Black) | --- ### 4. Wiring Diagram Overview The rear terminal block is organized to keep sensitive signal wires separate from power wires: 1. **Terminals 1-2:** Alarm Output 1 (Relay) 2. **Terminals 3-4:** Alarm Output 2 (Relay) 3. **Terminals 5-6:** DC Power Input (24V) 4. **Terminals 7-8:** Analog Input Signal ---