ACR122S – Communication Protocol
Version 2.01
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106 kbps type A
The field is optional and is present only when the host controller wants to initialize a target with a
known UID.
In that case, InitiatorData[] contains the UID of the card (or part of it). The UID must include the
cascade tag CT if it is cascaded level 2 or 3.
Cascade Level 1
UID1 UID2 UID3 UID4
Cascade Level 2
UID1 UID2 UID3 UID4 UID5 UID6 UID7
Cascade Level 3
UID1 UID2 UID3 UID4 UID5 UID6 UID7 UID8 UID9 UID10
106 kbps type B
In this case, InitiatorData[] is formatted as following:
AFI (1byte)
[Polling Method]
AFI
The AFI (Application Family Identifier) parameter represents the type of
application targeted by the device IC and is used to preselect the PICCs before
the ATQB.
This field is mandatory.
Polling Method
This field is optional. It indicates the approach to be used in the ISO/IEC 14443-
3B initialization:
If bit 0 = 1: Probabilistic approach (option 1) in the ISO/IEC 14443-3B
initialization,
If bit 0 = 0: Timeslot approach (option 2) in the ISO/IEC 14443-3B
initialization,
If this field is absent, the timeslot approach will be used.
212/424 kbps
In that case, this field is mandatory and contains the complete pay load
information that should be used in the polling request command (5bypes, length
bytes is excluded)
106 kbps
InnoVision Jewel tag. This field is not used.
Data Out
Tag Response returned by the reader.
Direct Transmit Response Format
Response
Data Out
Result
D5 41
Status
[DataIn[]]
SW1 SW2
D5 4B
NbTg
[TargetData1[]]
[TargetData2[]]
