The **M2VF-AFW-R2/X1** is a high-precision, plug-in type signal conditioner (specifically a **V/f Converter**) manufactured by **M-System**. Its primary function is to convert a DC voltage input signal into a pulse frequency output signal. --- ### 1. Key Technical Specifications The model code "AFW" and suffix "R2/X1" define the specific electrical characteristics of this unit: | Component | Specification Details | | :--- | :--- | | **Input Signal (A)** | 4 – 20 mA DC | | **Output Signal (FW)** | Open Collector (Frequency range usually defined at factory) | | **Power Input (R2)** | 110V AC (Operating range 100 – 120V AC) | | **Special Option (X1)** | High-speed response or specific frequency calibration | | **Accuracy** | ±0.1% | | **Isolation** | 3-way isolation (input to output to power) | --- ### 2. Functional Description This device acts as an interface between analog sensors and digital counting systems (like PLCs or high-speed counters). * **V/f Conversion:** It translates the magnitude of the analog current (4-20mA) into a proportional pulse rate (Hz). For example, 4mA might represent 0Hz, while 20mA represents 1000Hz. * **Galvanic Isolation:** It protects sensitive control equipment by isolating the field signal from the internal logic and the power supply, preventing ground loops. * **Totalizing Applications:** It is most commonly used for flow meters where the instantaneous flow (analog) needs to be integrated over time to find the total volume (pulses). --- ### 3. Electronic Architecture The internal circuitry consists of several critical stages: 1. **Input Conditioning:** A precision shunt resistor converts the 4-20mA current into a stable voltage. 2. **Integrator Circuit:** An operational amplifier-based integrator charges at a rate proportional to the input voltage. 3. **Comparator & Reset:** Once the integrator reaches a threshold, a comparator triggers a discharge (reset) and generates a pulse. 4. **Output Driver:** An **Open Collector (NPN)** transistor output. This requires an external pull-up resistor and power supply to interface with a digital input. --- ### 4. Terminal Connections (Typical) | Terminal | Function | Description | | :--- | :--- | :--- | | **1 & 2** | Input (+) / (-) | 4 – 20 mA DC loop | | **3 & 4** | Output (+) / (-) | Pulse output (Open Collector) | | **5 & 6** | Power Supply | 110V AC Line | | **7** | Ground | Earth connection |