The **M2VF2-B2-R2/UL** is a high-precision, plug-in type **Signal Transmitter (Frequency-to-Analog Converter)** manufactured by **M-System**. It is designed to take pulse frequency signals from sensors and convert them into standard analog process signals. --- ## 1. Core Technical Specifications | Feature | Specification | | :--- | :--- | | **Model Type** | Frequency Transmitter (Fixed Range) | | **Input Signal** | Dry contact, Open collector, or Voltage pulse | | **Output Signal** | 4 – 20 mA DC (Current Loop) | | **Power Input (R2)** | 100 – 240 V AC | | **Accuracy** | ±0.1% of span | | **Response Time** | Max. 0.5 sec (0 – 90%) | | **Housing Style** | Plug-in base (M2 series) | | **Safety Certification** | UL / cUL Class I, Division 2 | --- ## 2. Model Code Breakdown Understanding the specific suffixes provides insight into the electronic capabilities: * **M2VF2**: Base series for Frequency to Analog conversion. * **-B**: Input Type - Typically configured for a Voltage Pulse or Open Collector. * **-2**: Output Type - Standard 4 to 20 mA DC. * **-R2**: Power Supply - 100 to 240V AC (Wide range). * **-UL**: UL/cUL listing for North American safety standards, specifically for hazardous locations. --- ## 3. Electronic Functional Components The internal circuitry consists of several critical stages: ### A. Input Signal Conditioner This stage handles the incoming pulses. It includes a **Pulse Shaper** that cleans up noisy signals from flow meters or tachometers. It handles various waveforms, ensuring that only valid frequency pulses are processed. ### B. F/V Converter (Frequency-to-Voltage) The heart of the unit uses an integrated circuit to convert the pulse rate (Hz) into a linear DC voltage. The conversion is highly linear, ensuring that a 50% frequency input results in exactly a 50% signal output. ### C. Isolation Barrier To protect sensitive PLC/DCS equipment, the M2VF2 features **Three-way Isolation**: 1. **Input to Output** 2. **Input to Power** 3. **Output to Power** *This prevents ground loops and protects against high-voltage surges.* ### D. Output Driver The final stage converts the internal voltage into a stable **4-20mA current loop**. It is designed to drive loads up to 750Ω (when powered at 24V DC internally). --- ## 4. Key Electronic Features * **Zero/Span Adjustments:** Accessible on the front panel, allowing for fine-tuning of the electronic output without removing the unit from the base. * **Low-end Cutoff:** Often includes circuitry to force the output to 0% (4mA) if the input frequency drops below a certain threshold, preventing "jitter" at rest. * **Over-range Protection:** The output is electronically limited to approximately 110% of the signal to prevent damage to downstream equipment. ---