The **M2AC-A5D-R/Q** is a high-precision digital panel meter/indicator manufactured by **Autonics**. It is specifically designed to measure and display AC voltage or current in industrial automation systems. --- ### 1. Key Technical Specifications The part number suffix typically denotes the power supply, input type, and output configuration. | Feature | Specification Details | | :--- | :--- | | **Model Series** | M2AC Series (Digital Panel Meter) | | **Input Type** | AC Voltage or AC Current (Selectable/Model dependent) | | **Power Supply** | 100-240VAC 50/60Hz (Standard for 'A' models) | | **Display Method** | 4-digit 7-segment LED (Red) | | **Display Range** | 0 to 9999 | | **Output Options** | Relay Output (Control/Alarm) | | **Size** | DIN W96 x H48mm | --- ### 2. Electronic Component Breakdown #### A. Input Section (Signal Conditioning) * **Measurement Range:** It usually handles AC voltage up to 500V or AC current up to 5A (standard CT secondary). * **RMS Conversion:** The internal circuitry performs **True RMS** measurement, ensuring accuracy even when the AC waveform is distorted or contains harmonics. * **A/D Converter:** A high-resolution Analog-to-Digital converter translates the analog AC signal into digital data for the microprocessor. #### B. Processing & Control Unit * **Microcontroller (MCU):** The "brain" of the device. It handles the scaling (converting electrical input to a displayed value like RPM or Pressure), offset corrections, and timing for relay triggers. * **Non-Volatile Memory (EEPROM):** Stores user parameters and scaling factors so settings are not lost during power failure. #### C. Output & Interface * **Relay (R):** The 'R' in the suffix signifies a **Relay contact output**. This allows the meter to act as a controller—for example, tripping a circuit breaker or turning on a fan if the voltage exceeds a set limit (High/Low alarm). * **Display Drive:** A dedicated driver circuit powers the high-visibility LED segments. --- ### 3. Application Use Cases 1. **Industrial Power Monitoring:** Measuring the current draw of a 3-phase motor to prevent overload. 2. **Generator Sets:** Monitoring output voltage to ensure stability before connecting loads. 3. **Control Panels:** Serving as a visual feedback interface for operators to monitor system health. --- ### 4. Installation Precautions * **Wiring:** Ensure that the input terminals (AC High/Low) are not swapped with the power supply terminals to prevent internal damage. * **Current Transformers (CT):** If measuring currents higher than 5A, an external CT must be used and the "Scaling" function programmed into the M2AC.