XRAG2

XRAG2 command descriptions

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Figure 18.

Reader-to-tag and tag-to-reader communication timings

Collided Reply

ai12334b

No Reply

Invalid ACK

Reader

Tag

Query

QueryRep

QueryRep

ACK

QueryRep

RN16

RN16

Collision

detected

No

Reply

No

Reply

Reader

Select

Query

ACK

QueryRep

QueryRep or

QueryAdjust

if EPC is valid

NAK is EPC

is invalid

Carrier Wave

Carrier Wave

RN16

PC + EPC + CRC16

NAK

Carrier Wave

Carrier Wave

Table 10.

Parameter

Description

Conditions

Min

Nominal

Max

(5)

Delay between

end of Reader

command and

beginning of tag

answer.

Measured between the

last rising edge of Reader

command signaling and

the first rising edge of tag

reply

× (1_FT) – 2µs

× (1_FT) + 2µs

(6)

Delay between

tag reply and

next Reader

command.

Measured from the last

falling edge of the last bit

of tag reply to the first

falling edge of reader

command signaling.

command when the tag does not reply.

Minimum time between reader command

2.0 RTcal

1.

2.

Characterized only.

3.

If a Reader issues a new command during an tag reply, it does not demodulate the command.

4.

See EPCglobal Class 1 generation 2 RFID UHF specification, revision 1.0.9 for more detailed information.

5.

FT is the tag-to-reader link frequency tolerance.

6.

– without receiving a valid command, the tag returns to the Arbitrate state

– during the reception of a valid command, the tag executes the command

– during the reception of an invalid command, the tag returns to the Arbitrate state upon determining that the command is

invalid