Impact Of Secondary Fields - Siemens SIMATIC RF300 System Manual

4.1.4

Impact of secondary fields

Secondary fields in the range from 0 to 20 mm always exist.
They should only be applied during planning in exceptional cases, however, since the
read/write distances are very limited. Exact details of the secondary field geometry cannot be
given, since these values depend heavily on the operating distance and the application.
Secondary fields without shielding
The following graphic shows typical primary and secondary fields, if no shielding measures
are taken.
Figure 4-1
In this arrangement, the reader can also read tags via the secondary field. Shielding is
required in order to prevent unwanted reading via the secondary field, as shown and
described in the following.
SIMATIC RF300
System Manual, 01/2009, A5E01642529-03
Secondary field without shielding
RF300 system planning
4.1 Fundamentals of application planning
35