The **M2UDS-4W5-R/N** is a specific model of a **Digital Speedometer/Tachometer Indicator** typically manufactured by companies like **Autonics** (or similar industrial automation providers). This device is designed for precise measurement and display of rotational speed, frequency, or flow rates in industrial environments. ### 1. Key Technical Specifications Below is a breakdown of the primary electronic and functional characteristics: | Feature | Specification | | :--- | :--- | | **Model Code** | M2UDS-4W5-R/N | | **Display Type** | 4-Digit LED Display (Red) | | **Power Supply** | 100–240VAC (Standard Universal AC) | | **Input Type** | Pulse Input (NPN/PNP Open Collector, Voltage Pulse) | | **Max. Display Range** | 0 to 9999 | | **Output Type** | Relay Output (R) or NPN Open Collector (N) | | **Sampling Cycle** | 0.05s to 10s (Adjustable) | | **Mounting Type** | DIN Rail or Panel Mount (M-series typically compact) | --- ### 2. Functional Components The device operates using several key electronic sub-systems: #### A. Input Stage * **Signal Processing:** It accepts high-speed pulses from proximity sensors, rotary encoders, or photoelectric switches. * **Filtering:** Includes digital filters to eliminate noise or "chatter" from mechanical contacts to ensure accurate counting. #### B. Microcontroller (MCU) * **Logic Unit:** The internal CPU calculates the frequency ($f$) based on the time interval between pulses. * **Scaling:** It allows the user to apply a "Prescale" value. For example, if a wheel produces 10 pulses per revolution, the MCU divides the input by 10 to display the actual RPM. #### C. Output & Control * **Comparative Output:** The suffix **"R"** usually denotes a **Relay output**, while **"N"** denotes an **NPN transistor output**. These are used for alarms (e.g., if the speed exceeds a set limit, it triggers a motor stop). * **Hysteresis:** Electronic logic prevents the output from "flickering" when the speed fluctuates right at the setpoint. --- ### 3. Wiring Configuration Typical wiring for the M2UDS series follows this logic: ```text [Power Terminals] --- L / N (100-240VAC) [Input Terminals] --- 12VDC Out (for sensor), Input Signal, GND [Output Terminals] --- Common, NO (Normally Open), NC (Normally Closed) ``` --- ### 4. Application Examples 1. **Conveyor Belt Speed:** Measuring the meters per minute (m/min) of a production line. 2. **Motor RPM:** Monitoring the rotational speed of an industrial motor via a proximity sensor. 3. **Flow Metering:** Displaying liters per minute based on pulse output from a flow sensor.