The **M2UDS-J5-R2/N** is a specific model within the **M2UDS series**, which are **Compact Digital Panel Meters** manufactured by **M-System** (now often branded as MG CO., LTD). These devices are designed to take an analog signal and display it digitally, often providing signal conditioning or alarm outputs. --- ### 1. Model Code Breakdown Understanding the electronic capabilities requires looking at the specific suffixes in the part number: | Code Segment | Meaning | Technical Specification | | :--- | :--- | :--- | | **M2UDS** | Series Name | 1/8 DIN size digital panel meter (plug-in type). | | **J5** | Input Type | **DC Voltage/Current Input.** (Typically programmable or specific to 4-20mA / 1-5V). | | **R2** | Output Type | **Relay Contact Outputs.** Usually indicates 2-point (High/Low) alarms. | | **N** | Power Supply | **24V DC** power supply (Non-isolated or specific voltage range). | --- ### 2. Core Electronic Components & Features The device functions as a specialized **Analog-to-Digital Converter (ADC)** integrated with a display and control logic. #### A. Input Section * **Signal Conditioning:** Converts incoming analog signals (like 4-20mA from a sensor) into a voltage measurable by the internal processor. * **Isolation:** High-quality panel meters provide galvanic isolation between input, power, and output to prevent ground loops. #### B. Processing & Display * **Microprocessor:** Handles scaling (translating a 4-20mA signal into a human-readable value like 0-100% or 0-500 Liters). * **LED Display:** Features a high-brightness red LED display (usually 3.5 or 4 digits) for industrial visibility. #### C. Output Section (R2) * **Relays:** Contains two mechanical relays. These are "Dry Contacts" used to trigger external alarms, stop pumps, or signal a PLC when a specific threshold is reached. * **Hysteresis Control:** Internal electronics allow setting a "deadband" to prevent the relays from chattering if the input signal fluctuates near the setpoint. --- ### 3. Technical Specifications Table | Feature | Specification | | :--- | :--- | | **Display Range** | -1999 to 9999 (depending on scaling) | | **Input Impedance** | Voltage: $\ge 1 M\Omega$; Current: $100 \Omega$ to $250 \Omega$ | | **Output Rating** | 250V AC @ 3A / 30V DC @ 3A (Resistive load) | | **Operational Power** | 24V DC ($\pm 10\%$) | | **Mounting** | Plug-in socket (standard for M-System M2 series) | --- ### 4. Typical Application Circuit The M2UDS acts as the bridge between a sensor and a control system: 1. **Input:** Connected to a pressure transmitter (4-20mA). 2. **Display:** Shows "15.0 PSI". 3. **Relay 1 (High):** Closes a circuit to turn on a warning light if pressure exceeds 20 PSI. 4. **Relay 2 (Low):** Closes a circuit to shut down a motor if pressure drops below 2 PSI.