The **XT09-4II-R-NA** is an industrial-grade wireless radio modem manufactured by Digi International (formerly MaxStream). It belongs to the **XTend** family of 900MHz frequency-hopping spread spectrum (FHSS) modules. Below is a breakdown of the electronic components, specifications, and features of this specific part. --- ### 1. General Specifications The XT09-4II-R-NA is designed for long-range, robust data transmission in environments where interference is high. | Feature | Specification | | :--- | :--- | | **Frequency Range** | 902 - 928 MHz (ISM Band) | | **Communication Type** | FHSS (Frequency Hopping Spread Spectrum) | | **Indoor Range** | Up to 3,000 feet (900 m) | | **Outdoor/Line-of-Sight Range** | Up to 40 miles (64 km) with high-gain antenna | | **RF Data Rate** | 9.6 kbps or 115.2 kbps | | **Interface** | RS-232 / RS-485 (Depending on enclosure/baseboard) | | **Regulatory** | FCC (USA), IC (Canada) - "NA" suffix stands for North America | --- ### 2. Electronic Hardware Components The device is a self-contained radio system. Key internal components include: #### A. The RF Transceiver Core At the heart of the device is a powerful 900 MHz transceiver capable of putting out up to **1 Watt (30 dBm)** of power. * **FHSS Engine:** Unlike fixed-frequency radios, this jumps across 50+ channels to avoid jamming and interference. * **Sensitivity:** High receiver sensitivity (typically -110 dBm at 9.6 kbps) allows it to pick up very weak signals over long distances. #### B. The "4II" Configuration The part number suffix `4II` typically denotes specific interface and housing characteristics: * **Interface:** Serial communication support (RS-232/422/485). * **Power Supply:** Built-in voltage regulation allowing for wide input ranges (typically 7V to 28V DC). #### C. Connectivity Ports * **Antenna Port:** Usually features an **RPSMA** (Reverse Polarity SMA) connector for external antennas. * **Data Port:** A DB-9 or similar connector for serial data input/output. --- ### 3. Key Electronic Features 1. **Low Power Modes:** Includes "Sleep" modes to conserve power for remote sites running on solar or batteries. 2. **Addressing:** Supports peer-to-peer, point-to-point, and point-to-multipoint topologies. 3. **Error Correction:** Uses 24-bit CRC (Cyclic Redundancy Check) to ensure data integrity over the air. 4. **Signal Strength (RSSI):** Provides Received Signal Strength Indicator values to the host system for diagnostic monitoring. --- ### 4. Application Context Because this module operates in the 900MHz band, it penetrates walls and foliage much better than 2.4GHz (Wi-Fi/Bluetooth) systems. It is commonly found in: * SCADA (Supervisory Control and Data Acquisition). * Remote tank level monitoring. * Agricultural irrigation control. * Unmanned Aerial Vehicles (UAV) telemetry.