XRA00 Datasheet, PDF (12/40 Pages) STMicroelectronics – UHF, EPCglobal, Contactless Memory IC 96 bit ePC with Inventory and Kill Function

XRA00
Coast Interval
In order for the XRA00 to be able to detect the next
Transaction Gap, the Reader must start the next
transaction within t_coast (see Figure 15.). This re-
Figure 15. Coast Interval
striction does not apply when the carrier has been
turned off long enough (at least for t_Reset) for DC
power to be removed from the XRA00 as the
XRA00 will re-synchronize at the next power-up.
End of prior sequence
EOF
transaction gap or carrier on
tCoast
ScrollID
Tag Response Windows
Next sequence
Transaction gap
PingID
Bin Response Window
ai10754
Ping Reply Bin Collapse
The Reader may optionally shorten the Ping trans-
action time by shortening the Bin response win-
dow. The Reader may listen to a XRA00 reply
during the Bin response window for a minimum
time of 4t₀ (= t_{tagscrollDell} max), which is half the
standard BIN response window time. If no XRA00
response is detected, the Reader can generate
the next BIN pulse. This condition may be applied
to each of the 8 BIN intervals if the Reader detects
no reply from a XRA00. The middle Bin response
Figure 16. Collapsed Ping Response
window shown in Figure 16. has been shortened
due to no XRA00 reply.
A Bin response window may not be collapsed
(shortened) if an answer from the XRA00 is detect-
ed. If the Reader collapses an occupied Bin inter-
val, the reply from the occupying XRA00 may
overlap the collapsed Bin response window and
continue into the next one. The Reader may de-
code the overlapping reply as a collision in the
next Bin response window and will have to solve
the case.
Bin Response Window
tfwhmBinRW = 8 x t0
Tag answer
Bin Pulse
tfwhmBin = 3/8 t0
Collapsed Bin
Response
Window = 4 x t0
No Tag answer
Bin Response Window
tfwhmBinRW = 8 x t0
Tag answer
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