The **M2EXR-R/Q** refers to a high-performance, plug-in type multi-output signal conditioner (specifically a dual-output isolator) from the M2 series by **M-System** (now MG CO., LTD). Below is a detailed breakdown of its electronic characteristics and specifications. --- ## 1. Core Functional Overview The M2EXR-R/Q is an **Excitation Isolator**. Its primary electronic function is to provide a stable DC voltage to a 2-wire transmitter (Excitation) while simultaneously converting the 4–20 mA current loop signal from that transmitter into two isolated DC output signals. ### Key Electronic Features: * **Galvanic Isolation:** Provides 3-way isolation (Input to Output 1 to Output 2 to Power). * **Dual Output:** Allows one input to be split into two independent, buffered signals. * **High-Density Design:** Uses a plug-in socket base for easy maintenance without disconnecting wires. --- ## 2. Technical Specifications | Feature | Specification Details | | :--- | :--- | | **Input Signal** | 4 – 20 mA DC (from 2-wire transmitter) | | **Excitation Voltage** | 24 – 28 V DC | | **Output 1 & 2** | Options include 4–20mA, 0–20mA, 1–5V, 0–10V DC | | **Power Input (R)** | 24V DC (Operational range 24V ±10%) | | **Isolation Resistance** | 100 MΩ minimum at 500V DC | | **Dielectric Strength** | 2000V AC @ 1 minute (Input to Output to Power to Ground) | | **Response Time** | ≤ 0.5 seconds (0 – 90%) | --- ## 3. Circuit Components & Design The device is composed of several critical electronic sub-systems: ### A. Power Supply Section This section converts the 24V DC input into internal regulated voltages. It includes filtering to suppress electromagnetic interference (EMI) and protects the internal logic from surges. ### B. Excitation Supply (Transmitter Power) The module acts as a power source for field instruments. It limits current (short-circuit protection) to ensure that a fault in the field wiring does not destroy the isolator. ### C. Isolation Barrier Using **optical or magnetic coupling**, the electronic circuit "breaks" the physical electrical connection between the field (Input) and the control system (Output). This prevents ground loops and protects PLCs/DCSs from high-voltage transients. ### D. Signal Conditioning & Scaling Precision operational amplifiers and resistor networks convert the input current into the desired output voltage or current. The "Q" suffix in the model often denotes specific custom options or certifications (like "Non-HART" compatible or specific coating). --- ## 4. Wiring Configuration | Terminal | Function | Description | | :--- | :--- | :--- | | **1 / 2** | Output 1 | Primary signal to Controller/PLC | | **3 / 4** | Output 2 | Secondary signal for monitoring/recording | | **5 / 6** | Input | Connection to the 2-wire transmitter | | **7 / 8** | Power Supply | 24V DC Input | ---