Transponder technologies, applications and benefits

The needs of data collection and identification in automation and distribution have traditionally been met by bar codes, optical character recognition, magnetic stripes or manual means. In recent years a number of radio frequency identification systems have become available which can offer operational advantages over existing methods. They all feature a small electronic transponder or `tag´ of some type attached to the product or product carrier. Data held within the tag´s memory can be automatically read, and in some cases written, without line of sight at ranges typically up to 1 metre even in very harsh environments. Their high data integrity and flexibility has led to uses in automation, FMS, materials handling, vehicle tracking, personnel tracking and animal feeding systems. There are a number of options open to the designers of transponders, and the particular methods chosen greatly influence the devices´ operational properties and suitability for particular applications. To enable system users and designers to compare the various types and assess the potential benefits of a transponder based identification system, an overview of their basic principles is presented followed by specific examples of their use in a variety of applications