Implementation Of Uhf Rfid Installations; Preparation Phase - Siemens SIMATIC RF650R Configuration Manual

Appendix
A.1 Planning and installation of UHF read points
This restriction does not apply with circular polarization. This means that linear antennas can
only be used if the alignment of the transponder is defined. On the other hand, one
advantage of linear antennas is that they react less sensitively to reflections. Circular
antennas can also be used with differing alignments of the transponder and achieve constant
results. It has been shown that with a defined transponder alignment, the linear antenna
normally produces the best results.
The antenna gain is a factor for the directivity and the efficiency of an antenna. The
directivity and degree of efficiency of antennas with a high antenna gain (e.g. RF642A) result
in stronger signals. This means that you can also use a weaker transmit power or
transponder replies. Here, however, there is a risk of overshoots. With an antenna with a
weak or negative antenna gain, such as the RF620A antenna, a significantly higher transmit
power needs to be used for a comparable distance. On the other hand, this antenna
significantly reduces the risk of overshoots at the same transmit power.
A.1.2

Implementation of UHF RFID installations

The use of UHF RFID systems requires careful planning and preparation to avoid problems
during commissioning and operation.
A.1.2.1

Preparation phase

Device selection
When selecting the suitable RFID hardware, remember the following minimum criteria:
● Integration in a control/IT environment
● Degree of protection
● Size of the identification range
● Type, number and position of the transponders in the antenna field
● Reflecting and absorbent materials in the vicinity of the antenna
● Distance between the antenna or the reader and the transponder
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SIMATIC RF650R/RF680R/RF685R
Configuration Manual, 10/2015, C79000-G8976-C386-03