XRA00SBN18I1GE STMicroelectronics, XRA00SBN18I1GE Datasheet - Page 34

• Manufacturer Part Number: XRA00SBN18I1GE
• Manufacturer: STMicroelectronics

Specifications of XRA00SBN18I1GE

• Lead Free Status / RoHS Status: Compliant

XRA00
Using this information, the Reader may issue a
second PingID command to explore the popula-
tion of XRA00 devices in bin 3, reserving the
XRA00 devices detected in bin 5 for later analysis:
Query 2
[CMD] = 00001000
[PTR] = 00000000
[LEN] = 00000100
[VALUE] = 0111
This command explores 3 bits farther into the tree
towards the highest memory location from the
memory address containing the bits 0111
ure
contain the XRA00 devices. The two branches
shown in the second half of the drawing contain
groups of XRA00 devices that match Query 2.
These are the same XRA00 devices that respond-
ed to the first query in bin 3.
In this new query, the XRA00 modulation during
the reply interval will take place in bins 1 (response
0010111
sponse 1110111
bold in
Figure 36. Reader Modulations and XRA00 Backscatter During PingID Reply for Query 1
34/40
37., the bold borders show the branches that
Tag Backscatter
Figure 37.
b
), 6 (response 1100111
Modulation
Reader
Bin
b
b
(7)
) as shown in
b
b
b
The Reader knows 7 address
(PingID)
(0)
(4)
000
Figure 38.
b
) and 7 (re-
001
b
. In
and in
Fig-
010
bits of these XRA00 devices and at least 4 bits of
information concerning the other XRA00 branch
affected by Query 1 but reserved for later analysis.
Although it is not the fastest way to isolate and
identify XRA00 devices, the Reader may continue
with this method and use the PingID command to
follow a branch through the XRA00 ID space until
it has explored the entire XRA00 address and 16-
bit CRC of the XRA00 address.
The recommended way to perform an analysis of
a population of XRA00 devices is to take advan-
tage of the Reader's ability to detect contention in
the reply intervals. The "divide by eight" feature of
the PingID command makes it possible to very
quickly reduce the number of XRA00 devices re-
plying in each bin. Simulations with populations of
100 XRA00 devices show that with random ad-
dresses, an average of less than 4 PingID com-
mands are needed to isolate one XRA00 device. If
only one XRA00 replies in a given bin, the Reader
can decode the 8 bits of information sent from the
XRA00 and issue a ScrollID command to that
XRA00 using the [PTR] [LEN] and [VALUE] data
that successfully isolated the XRA00.
011
100
101
110
111
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