User Guide

Table Of Contents
Gen2 Tag Commands
128
(Currently available at http://www.alientechnology.com/docs/
Load_Image_Application_Note_1.pdf - Contact Alien Technology for more details).
The PC Word field, in the table on the previous page, corresponds to the PC Word in the
Tag EPC memBank defined in the Gen2 Specification and is shown in the following table:
Alien Higgs PC Bits
The PC Word in the Write Tag Specific command allows you to specify the NSI Bits and
the length of the EPC that you want to write into the tag. The RFU bits are always zero
and the PC Bits are determined by the EPC length as specified in the Gen2 Specification
and the Higgs Tags Application Notes.
To use the extended format of the Gen2 Tag Specific command but keep the NSI bits
intact, set option=0x03. This signals the reader to ignore the NSI bits of the PC Word sent
to the reader along with the command.
In the example on the previous page, after the execution of the Gen2 Tag Specific
command, the reader writes the 96-bit EPC 0x112233445566778899AABBCC, the Kill
Password 0x01234567, the Access Password 0x89ABCDEF into the tag without
changing the NSI bits of the tag and locks the EPC memBank.
However, to access and write the NSI bits into the tag, set the third bit of the option field to
1 (option=0x07). In the example, if option is set to 0x07, the NSI bits are overwritten by
zeros.
The following table summarizes the option field values and the action that is taken:
Bit Number
15 14 13 12 11 10 9 8 7 6
Field Name
PC Bits RFU RFU
Default Values
XXXXX0 0 000
54 3 210
NSI Bits
00 0 000