The **Z2AD-R** is a specific electronic module, typically part of the **Z-PC Series** from SENECA. It is a high-performance **2-channel Analog Input to Modbus RTU interface**. It is widely used in industrial automation for signal conditioning and data acquisition. --- ## 1. Core Technical Specifications | Feature | Description | | :--- | :--- | | **Input Channels** | 2 Independent Channels | | **Input Signal Types** | Voltage (±10V) or Current (±20mA) | | **Resolution** | 16-bit A/D Conversion | | **Communication** | RS485 Modbus RTU Protocol | | **Power Supply** | 10 - 40 Vdc / 19 - 28 Vac | | **Isolation** | 1.5 kVac (3-way: Power / Input / Communication) | | **Mounting** | 35mm DIN Rail (IDC10 connector compatible) | --- ## 2. Key Electronic Components & Functions ### A. Analog-to-Digital Conversion (ADC) The heart of the Z2AD-R is a high-resolution **16-bit ADC**. This allows the device to convert precise physical measurements (like pressure or flow) into digital data with 65,536 discrete levels. ### B. Galvanic Isolation To protect the PLC or SCADA system from electrical surges or ground loops, the internal circuitry features **3-way galvanic isolation**. This physically separates the input sensors, the power supply, and the communication bus. ### C. Microprocessor & Memory The module contains an onboard microcontroller that handles: * **Linearization:** Converting raw electrical signals into engineering units. * **Filtering:** Digital noise reduction for stable readings. * **Modbus Stack:** Managing data requests from the master controller. ### D. Dip-Switches Located on the side or under the front panel, these physical switches are used to manually set: * Baud rate (e.g., 9600 to 115k bps). * Modbus Address (Node ID). * Input signal range (Voltage vs. Current). --- ## 3. Connection Pinout (General) | Pin No. | Label | Function | | :---: | :--- | :--- | | **1** | +V | Power Supply (Positive) | | **2** | GND | Power Supply (Ground) | | **7-8** | Input 1 | Analog Input Channel 1 (+ / -) | | **10-11** | Input 2 | Analog Input Channel 2 (+ / -) | | **IDC10** | RS485 | Communication & Power via DIN Rail backplane | --- ## 4. Usage Scenario In a typical application, a sensor (like a 4-20mA pressure transducer) is wired to **Input 1**. The Z2AD-R processes this signal and stores the value in a **Modbus Holding Register**. A PLC or PC then reads that register over two wires (RS485) to monitor the pressure remotely. ---