Identification Systems - Introduction
1.3Overview of identification systems
Pepperl+Fuchs offers inductive, microwave-based and optical identification systems, which are tailored to different industrial applications.
Components of an identification system
Mostly, identification systems consist of a control unit, read/write heads and code or data carriers. Code carriers contain a worldwide unique fixed code of typically 40bits (2
40 = 1,099,511,627,776 possibilities). Data carriers have a freely usable memory area, which can be overwritten many times. Additionally, data car-riers often have a fixed code area. This way, both unique identification and a special piece of information can be saved in a targeted way. The memory areas typically have a size of 1Kbits to 256Kbits. The fixed codes can be read by read/write heads and data can be read from or written to the data area of data carriers. This is done on the basis of commands sent by the control unit to the read/write heads. Several read/write heads can be con-nected to one control unit, which also serves as the interface to the higher-level control. Communication takes place via the current Fieldbusses such as EtherNet, Profibus, DeviceNet, Interbus or via a serial interface. Wiring between the control unit and the read/write heads is realised via screened signal cables in order to reduce the influence of possible sources of disturbance.In a system, several hundred read/write points (ID points) can be realised and connected to a controller unit by means of the
Fieldbus and the respec-tive number of control units.
Inductive identification systems
Inductive identification systems operate according to the
industrial transformer princi-ple in the near field, i.e. the read/write cone is locally restricted and no wave propagates from the read/write heads. Depending on the size of the coil, typical ranges are between some centimetres and approximately half a me-
ter. The code and data carriers mostly operate passively and reflect or mod-ulate the transmitter signals. For this purpose, the energy is taken from the transmitter energy.These systems are particularly suitable for applications in the area of auto-mation, material flow control in
industrial production technology, acquisition of oper-ating data or the identification of objects such as
storage containers, pallets, work piece carriers and similar items. Near field
Microwave identification systems
Microwave identification systems operate according to the principle of Hertz dipole in the far field, making it possible to reach larger read/write distances. Typical ranges extend to a couple of meters. The code and data carriers have an energy source of their own to supply the internal electronic compo-nentry. Communication is realised according to the back-scatter principle. Typical applications of microwave systems can be found in the identification of larger objects, for example, in automobile production, in logistic areas for the barrier control for vehicles or for simultaneous identification of several goods on a
conveyor manufacturer unit. Far field
Issue date 2005-08-18 - Catalogue Identification Systems 2005/2006 10
Subject to reasonable modifications due to technical advances.Copyright Pepperl+Fuchs, Printed in German y Pepperl+Fuchs Group • Tel.: Germany +49 621 776-0 • USA +1 330 4253555 • Singapore +65 67799091 • Internet http://www.pepperl-fuchs.co m