Multi-Reader Environment - Balluff BIS U-4A7-082-01C-07-S4 Betriebsanleitung

BIS U-4A7-082- _1C-07-S4
Industrial RFID system - Read/write head
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Application planning (continued)
If a larger area is to be covered, several read/write heads
can also be aligned to the same location, with each read/
write head then illuminating part of the desired coverage
area. It is important here that the detection is staggered so
that a data carrier population is not processed by several
devices at the same time.
When operating several devices, the lateral and rear
radiation should be taken into account. Otherwise, the
devices may interact with each other if they transmit or
receive simultaneously. A lateral and rear distance of
20 cm to neighboring devices should be maintained. To
avoid interactions, the devices can be synchronized so
that they do not transmit simultaneously. If this is not
possible, shielding, e.g. with RF absorber material or other
conductive materials, can be helpful.
Optional shielding made of conductive material
Fig. 5-4: Example of increasing the detection range with two devices
and shielding
5.3

Multi-reader environment

When using several read/write heads (readers) in a
confined space, care should be taken to ensure that they
maintain a safe distance from each other if they are
operated simultaneously without time synchronization.
Care should be taken to ensure that a read/write head is
not mounted in the detection range of another and that the
read/write heads do not influence each other through
lateral or rear radiation. A lateral and rear distance of about
20 cm should therefore be maintained.
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Fig. 5-5:
Common data carrier
Reader 1
population
Reader 2
Fig. 5-6:
If the above or similar scenarios cannot be avoided due to
the existing installation situation, it is recommended that
the individual read/write heads are synchronized in terms
of time. It must be ensured on the control side that readers
which could influence each other do not send or receive
simultaneously. Read/write assignments should then first
be processed by Reader 1, for example. Only when the
read/write operation is complete should assignments be
passed to Reader 2.
Alternatively, consideration can be given to shielding
immediately adjacent devices from each other with
conductive or RF-absorbing material. However, effective
shielding is often difficult to achieve, so time
synchronization is preferable to shielding.
For BIS U-4A7 country variants that allow direct channel
selection (for country-specific details on conformity and
approval, see enclosed information or visit
www.balluff.com on the product page), shielding can
also be achieved by having adjacent devices operate on
different channels (frequencies) (see chapter 5.4 on
page 14).
Reader 1 Reader 2
Reader 2 is within the detection range of Reader 1
Time synchronization or shielding
necessary.
Example: Reader 1 and Reader 2 influence each other by
lateral radiation
english
Time
synchronization
necessary.
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