ACR122T – Application Programming Interface
Version 2.02
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Appendix B. APDU Command and Response Flow
for ISO 14443-compliant Tags
Assume an ISO 14443-4 Type B tag is used.
<< Typical APDU Command and Response Flow >>
PC
Sequences
Reader
USB Interface
(12 Mbps)
Tag
RF Interface
(13.56 MHz)
1. The command
is sent.
Contactless Related Command
[APDU Command]
e.g. [00 84 00 00 08h] (Get
Challenge)
Tag-specific
Command Frame
[APDU Command]
embedded in ISO
14443 Frame
2. The response
is received.
Contactless Related Response
[APDU Response]
e.g. [11 22 33 44 55 66 77 88h]
(90 00h)
Tag-specific
Response Frame
[APDU Response]
embedded in ISO
14443 Frame