The **FUD-H2-R/Q** is a high-performance, single-channel ultrasonic flow transmitter (or flow meter) typically used in industrial automation and liquid management systems. It is designed to measure the velocity of liquids through pipes using ultrasonic waves. --- ### 1. Core Electronic Components and Architecture The device consists of several critical electronic modules that handle signal generation, processing, and output. | Component | Description | Function | | :--- | :--- | :--- | | **Ultrasonic Transducer** | Piezoelectric ceramic elements. | Converts electrical pulses into ultrasonic waves and vice versa. | | **Signal Processor (DSP)** | Digital Signal Processing chip. | Calculates the time difference ($\Delta t$) between upstream and downstream pulses. | | **Output Interface** | Analog and Digital circuitry. | Provides 4-20mA current loops and RS-485 (Modbus) communication. | | **LCD Display** | Backlit integrated screen. | Displays real-time flow rate, totalizer values, and error codes. | | **Power Module** | Voltage regulators and filters. | Converts input power (typically 24V DC) into stable internal voltages. | --- ### 2. Technical Specifications The "R/Q" designation often refers to specific output configurations or mounting styles within the series. * **Measurement Method:** Ultrasonic Transit-time. * **Operating Voltage:** 12–24V DC (typical for industrial sensors). * **Analog Output:** 4–20mA (represents flow rate). * **Digital Communication:** RS-485 (Modbus RTU protocol). * **Frequency:** Usually operates in the MHz range for high-resolution timing. --- ### 3. Electronic Features The FUD-H2 series is known for specific electronic protections and capabilities: 1. **Anti-Interference Circuitry:** Uses hardware filters to ignore electrical noise from nearby motors or pumps. 2. **High-Speed Sampling:** The electronic timing circuit measures time in nanoseconds, allowing for high accuracy even at low flow velocities. 3. **Non-Volatile Memory:** Stores configuration data and totalizer values so that data is not lost during a power failure. 4. **IP Protection:** The electronic housing is typically rated IP65 or higher to protect sensitive components from moisture and dust. --- ### 4. Wiring and Connection (Electronic Interface) The back of the unit or the internal terminal block generally follows this electronic pinout: ```yaml Terminal 1: V+ (24V DC Power) Terminal 2: V- (0V / Ground) Terminal 3: A+ (RS-485 Data Positive) Terminal 4: B- (RS-485 Data Negative) Terminal 5: I+ (4-20mA Signal Output) Terminal 6: I- (Signal Ground) ```