The **M2RTS-R-D4-R/UL** is a high-precision, rack-mounted signal conditioner (RTD transmitter) manufactured by **M-System**. It is designed to convert resistance temperature detector (RTD) signals into standard industrial DC output signals. Below is a breakdown of its technical specifications and electronic characteristics. --- ## 1. Model Number Breakdown Understanding the nomenclature helps define the electronic behavior of the unit: | Component | Code | Description | | :--- | :--- | :--- | | **Series** | M2RTS | RTD Transmitter (Plug-in base) | | **Input** | R | RTD (Pt 100, JPt 100, etc.) | | **Output** | R | RTD Simulating Output (Resistance output) | | **Power Input** | D4 | 110V DC | | **Option** | R | High-reliability/High-speed response | | **Certification**| UL | UL/C-UL Class I, Div 2 Approval | --- ## 2. Key Electronic Specifications ### Input Characteristics The device interface supports 3-wire RTD sensors. It uses a constant current bridge circuit to measure the resistance change. * **Sensor Types:** Pt 100 (IEC), JPt 100 (JIS). * **Excitation Current:** Typically $\approx 2mA$. * **Allowable Leadwire Resistance:** Maximum $20 \Omega$ per wire. ### Output Characteristics The "R" output signifies a **Resistance Output**, meaning this device acts as a simulator or a retransmitter that provides a variable resistance to a secondary system (like a PLC or DCS RTD card). * **Output Range:** Matches the input resistance characteristics. * **Response Time:** $\le 0.5$ seconds (for 0–90%). ### Power & Isolation * **Power Input:** 110V DC ($\pm 10\%$). * **Isolation Structure:** 3-way isolation (Input to Output to Power). * **Dielectric Strength:** 2000V AC @ 1 minute (Input to Output to Power to Ground). --- ## 3. Electronic Design Features ### Linearization The unit features built-in electronic **Linearization**. Since the resistance-to-temperature relationship in RTDs is slightly non-linear, the internal circuitry compensates for these curves to ensure the output is directly proportional to the temperature. ### Burnout Protection In the event of a sensor wire break, the electronic circuit is designed to drive the output to a specific state: * **Upscale Burnout:** Output goes to the maximum limit (Standard). * **Downscale Burnout:** Available as a configuration. ### Adjustment Potentiometers On the front panel, the device usually includes: 1. **Zero Adjustment:** Fine-tuning the lower end of the signal. 2. **Span Adjustment:** Fine-tuning the upper end of the signal. --- ## 4. Connection Diagram (General) ```text [ RTD INPUT ] [ SIGNAL CONDITIONER ] [ OUTPUT ] Term 1 (A) -----------| |----------- Term 4 Term 2 (B) -----------| M2RTS |----------- Term 5 Term 3 (B) -----------| |----------- Term 6 |__________________| | | [ 110V DC POWER ] ``` --- ## 5. Industrial Applications * **Data Acquisition:** Interfacing old RTD sensors with modern PLC systems. * **Ground Loop Elimination:** Using the 2000V isolation to prevent electrical noise from damaging sensitive control equipment. * **Hazardous Areas:** Because of the **UL** rating, it is suitable for environments where flammable gases might be present (Class I, Div 2).