Valid RN16: Tag responds with {handle}
2. Invalid RN16: No reply
FIGURE 3.20
Example transaction for ISO 18000 Part 6C.
Design Automation for RFID Tags and Systems 49
3.4.2 RFID Controller Behavior
Communication from the RFID interrogator (reader) is accomplished by transmitting the
primitive to the RFID tag using a standard air interface. The tag responds by changing the
current state and transmitting a designated response message to the interrogator. The user
has the capability of specifying the tag behavior in ANSI-C.
To simplify the user interaction, the RFID parser generates a template for the response
behavior indicating where the user must specify such custom behavior. Any C language
constructs (conditionals, loops, etc.) can be added (or left unchanged) by the user to check
the values of the ?¬?elds of the incoming primitive and to specify the values of the ?¬?elds of
the response. The template generated for the Query command is shown in Figure 3.23.
A ?¬?le containing similar templates for all the macros that were included in the macros
speci?¬?cation ?¬?le will be generated for the user.
The details involving size and ?¬?eld position in the command of the interrogator and the
corresponding response packet are handled by the compiler. Therefore, complexities
encountered in unpacking the command and subsequently packing the response can be
abstracted from the user, as shown in Figure 3.
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