Measures For Eliminating Field Disturbances - Siemens SIMATIC RF650R Configuration Manual

Appendix
A.1 Planning and installation of UHF read points
A.1.3.2

Measures for eliminating field disturbances

Using shields
To avoid reflections, you can fit UHF absorbent material. To do this, the absorbent material
is mounted at various suspected reflection points until the field disturbance no longer occurs.
Where possible, avoid the use of metal structures (for example housings) and use plastic
instead.
Even with reader-to-reader influence, you can use absorbent plates or shielding sheets.
Channel management
To operate the readers, depending on the country profile, you have between four and fifty
send channels available. Ideally, you should make the channel assignments manually in
STEP 7 Basic / Professional (TIA Portal) or in the WBM. This allows you to reduce reader-to
reader influence and if applicable field obliteration.
Table A- 1
Reader
Transmission
channel
Frequency
(MHz)
Use of multiple antennas
If you do not find the ideal antenna position to be able to identify the transponders in the
various positions and alignments, you have the option of using more antennas. Multiple
antennas mounted at different positions enlarge the identification range.
Enabling send pauses
If too many neighboring readers send at the same time, this causes overload of the radio
channels. In this case, enable the "Intermissions" function in the "Settings - General" menu
item to improve read reliability.
Varying the antenna polarization
By using linear or circular antennas, you can reduce field obliteration. This improves the
reader reliability in difficult radio conditions.
The RF685R reader also provides the option of operating the internal antenna both as a
linear, vertical, linear horizontal and circular antenna. If more than one polarization is
enabled, the polarization is changed automatically with each inventory. This increases the
probability of identification in difficult radio conditions.
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Example of a channel plan according to ETSI
Reader 1 Reader 2
4 10
865.7 866.9
Reader 3 Reader 4
7 13
866.3 867.5
SIMATIC RF650R/RF680R/RF685R
Configuration Manual, 10/2015, C79000-G8976-C386-03
Reader 5 ...
4 ...
865.7 ...