Siemens SIMATIC Ident System Manual page 33

Secondary fields without shielding
The following graphic shows typical primary and secondary fields, if no shielding measures
are taken.
Figure 4-8
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 RF200
System Manual, 09/2013, J31069-D0227-U001-A8-7618
Secondary field without shielding
RF200 system planning
4.1 Fundamentals of application planning
33