Siemens SIMATIC RF600 Series System Manual page 289

Transponder
7.1 Overview
7.1.1 Mode of operation of transponders
The transponder mainly comprises a microchip with an integrated memory and a dipole
antenna.
The principle of operation of a passive RFID transponder is as follows:
● Diversion of some of the high-frequency energy emitted by the reader to supply power to
the integrated chip
● Receiving commands from the reader
● Responses are transmitted to the reader antenna by modulating the reflected radio waves
(backscatter technique)
Figure 7-1
The transmission ranges achieved vary depending on the size of the transponder and
therefore its dipole antenna. In general the following rule applies: The smaller the
transponder and therefore the antenna, the shorter the range.
SIMATIC RF600
System Manual, 10/2016, J31069-D0171-U001-A19-7618
Mode of operation of transponders
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