<h1>RFID Card 125kHz: A Comprehensive Guide</h1> <p><strong>RFID card 125kHz</strong> technology has been a cornerstone of access control and identification systems for decades. From my personal experience working in facility security, the reliability and simplicity of these low-frequency cards are unmatched for basic proximity applications. I've always had a knack for understanding wireless technologies, and dissecting how these cards communicate with readers was a fascinating skill to develop. In my opinion, while higher frequency technologies like UHF RFID offer greater range, the 125kHz system's resilience to interference near metals and liquids keeps it highly relevant.</p> <h2>Technical Specifications and Parameters of 125kHz RFID Cards</h2> <p>Understanding the technical underpinnings is crucial. Here are detailed specifications for a typical <strong>RFID card 125kHz</strong> solution. *Please note: These technical parameters are for reference data; specifics need to contact backend management.*</p> <h3>Chip and Operating Details</h3> <ul> <li><strong>Operating Frequency:</strong> 125 kHz ± 5 kHz</li> <li><strong>Chip Type:</strong> EM4100-compatible or T5577 (re-writable)</li> <li><strong>Chip Code:</strong> Common formats include 64-bit Read-Only (e.g., EM4100) or 330-bit Read/Write (T5577).</li> <li><strong>Communication Protocol:</strong> Amplitude Shift Keying (ASK)</li> <li><strong>Data Rate:</strong> Typically 2-4 kbps</li> </ul> <h3>Physical Card Dimensions</h3> <ul> <li><strong>Standard Credit Card Size:</strong> 85.6mm x 54mm x 0.76mm (ISO/IEC 7810 ID-1)</li> <li><strong>Thicker Variants:</strong> Up to 1.2mm for added durability.</li> <li><strong>Chip/Coil Placement:</strong> Embedded antenna coil, usually 3-5 turns, located around the card's perimeter.</li> </ul> <h3>Performance Metrics</h3> <ul> <li><strong>Read Range:</strong> Up to 10 cm (4 inches), depending on reader power and antenna size.</li> <li><strong>Memory:</strong> Read-Only (RO) or Read/Write (RW) depending on chip. T5577 offers multiple blocks for data.</li> <li><strong>Power Source:</strong> Entirely passive, powered by the reader's electromagnetic field.</li> </ul> <h2>Entertaining and Practical Applica