RFID technology:
        It is contactless auto-ID technology. Its basic principle is that using the transmitting characteristic of coupling of radio frequency signals (inductance or electronmagnetic coupling) to achieve auto identification of objects.
        Basic components: there are 3 components in a basic RFID system: tags, readers and application software. Middleware is a key component of application software, it is a bridge that connects hardware such as tags and readers, and enterprise application software such as Enterprise Resource Planning (ERP) and Customer Relationship Management (CRM). Main task of middleware is to filter, gather, calculate and group the received data that relates to tags, reduce raw material sent to enterprise application from readers, and generate event data with semantic interpretation. In other words, middleware is the ‘nerve center’ of RFID system.
        Basic principles: basic workflow of system: reader sends RF signals of a certain frequency through antenna. When the RF card enters work area of antenna, induced current is generated, by which the RF card can be actived. The RF card sends its information through antenna, and the receiver receives this signal and transmits it to the reader. Reader adjusts and decodes the received signal and then transmits it to host system for processing. Host system estimates the card’s validity and then process and control accordingly, and sends instruction signals.