XRAG2 command descriptions

XRAG2

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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

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.

Power up and tag not killed

Ready

Select

Query(Q > 0)

start of inventory

Arbitrate

Reply

Acknowledged

QueryRep or QueryAdjust

and tag slot_counter

≠ 0

tag backscatters PC, EPC and CRC16

NAK if

EPC

not valid

QueryRep

or QueryAdjust

if EPC VALID,

Query (start a new round),

Select

ai12333b

QueryRep or QueryAdjust

and tag Slot_counter=0

Query (Q = 0)