## M2RTS-R-AE-R2/UL: Technical Overview The **M2RTS-R-AE-R2/UL** is a high-precision, plug-in type **Resistance Thermometer Transmitter** (RTD Transmitter) manufactured by **M-System**. Its primary function is to convert signals from an RTD (Resistance Temperature Detector) into a standard DC output signal (voltage or current) that is linear with temperature. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Input Type** | Pt 100 (RTD), 3-wire | | **Output Type** | 4 – 20 mA DC (Standard) | | **Power Input** | 100 – 240V AC (indicated by code "R") | | **Accuracy** | ±0.1% of span | | **Response Time** | ≤ 0.5 seconds (0 – 90%) | | **Burnout Protection** | Upscale standard (Downscale optional) | | **Certification** | UL/cUL Class I, Div 2 (indicated by "/UL") | --- ### 2. Breakdown of the Model Code To understand the electronic capabilities, it is essential to decode the nomenclature: 1. **M2RTS**: Base model for the Resistance Thermometer Transmitter. 2. **-R**: Power input specification (100V – 240V AC). 3. **-AE**: Output signal code (A: 4-20mA DC / E: 1-5V DC is often a secondary reference, but typically "A" denotes the primary current output). 4. **-R2**: Design revision or specific housing series. 5. **/UL**: Safety certification for North American standards (Hazardous locations). --- ### 3. Electronic Components and Construction The device is built using a **Plug-in Base** structure, allowing for easy maintenance without disturbing the field wiring. Internally, it consists of the following electronic stages: * **Input Circuitry:** Features a constant current source to drive the RTD and a bridge circuit to detect resistance changes. It includes 3-wire compensation to cancel out lead-wire resistance. * **Linearizer:** Since RTDs are slightly non-linear, this circuit corrects the signal to ensure the output is proportional to the temperature. * **Isolation Transformer:** Provides 3-way isolation (Input to Output to Power). This prevents ground loops and protects sensitive PLC/DCS equipment from electrical surges. * **Zero/Span Adjustments:** Accessible via the front panel for fine-tuning the calibration. --- ### 4. Wiring Diagram Representation Below is a simplified representation of the terminal connections: ```text TERMINAL ASSIGNMENT +-------+-------+-------------------------+ | Pin # | Label | Description | +-------+-------+-------------------------+ | 1 | U(+)| Power Supply (L) | | 2 | V(-)| Power Supply (N) | | 4 | + | Output (+) | | 5 | - | Output (-) | | 6 | A | RTD Input (A) | | 7 | B | RTD Input (B) | | 8 | B | RTD Input (B) | +-------+-------+-------------------------+ ``` ---