XRAG2_08 Datasheet, PDF (24/33 Pages) STMicroelectronics – 432-bit UHF, EPCglobal Class1 Generation2 and ISO 18000-6C, contactless memory chip with user memory

XRAG2 command descriptions
XRAG2
8.2.5
NAK
The XRAG2 supports the NAK command as described in the EPCglobal Class 1 generation
2 RFID UHF specification, revision 1.0.9.
This command restores tags to the Arbitrate state. Tags in Reply or Killed state remain in
the same state.
The algorithm for a single tag or multiple tag inventory is shown in Figure 17.
Figure 17. Example of an inventory round
Power up and tag not killed
Ready
Query(Q > 0)
start of inventory
Select
Query (Q = 0)
NAK if
EPC
not valid
QueryRep
or QueryAdjust
if EPC VALID,
Query (start a new round),
Select
Arbitrate
QueryRep or QueryAdjust
and tag slot_counter ≠ 0
QueryRep or QueryAdjust
and tag Slot_counter=0
Reply
tag backscatters RN16₁
ACK (RN16₁ within t₂)
Acknowledged tag backscatters PC, EPC and CRC16
ai12333b
1. Please refer to EPCglobal Class 1 generation 2 RFID UHF specification, revision 1.0.9 for a complete
description of each command and all state transition cases.
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