T
AG
P
ROGRAMMING
C
HAPTER
5
R
EADER
I
NTERFACE
G
UIDE
D
OC
. C
ONTROL
# 8101938-000 R
EV
05
80
Class I Tags (96-bit)
"Quark" and "Omega" Class I tags from Alien contain 96 bits of programmable
memory, of which 64 bits are user-programmable. The remaining 32 bits are
controlled by the reader to record state and checksum information inside the tag.
Checksum
EPC Code (or User ID Code)
Lock PC
Byte
0 1 0 1 2 3 4 5 6 7
0
0
Bit
0-7 8-15 0-7 8-15 16-23 24-31 32-39 40-47 48-55 56-63
0-7 0-7
Class I 96-bit Tag Memory Structure
The ID Code memory is address from left to right, where the leftmost bit (the
Most Significant Bit) is bit 0, and the rightmost bit (the Least Significant Bit) is bit
63. There is no restriction on the data that resides in this portion of the tag.
The Checksum is calculated over the 64 bits of the ID Code only. The checksum
is calculated and programmed into the tag automatically by the reader. This
checksum is calculated using the CCITT-16 standard.
The Lock and PassCode (PC) bytes stored at the end of tag memory are used to
lock a tag and kill a locked tag. Each of these codes takes exactly one byte. The
user can control the value of the PassCode, passing it in as a parameter to the
Lock command. The reader takes full control of the Lock byte, allowing it to flag
the tag as either locked or unlocked.
Class I Tags (128-bit)
"Lepton" Class I tags from Alien contain 128 bits of programmable memory, of
which 96 bits are user-programmable. The remaining 32 bits are controlled by
the reader to record state and checksum information inside the tag.
Checksum
EPC Code (or User ID Code)
Lock PC
Byte
0 1 0 1 2 3 … 9 10
11
0
0
Bit
0-7 8-15 0-7 8-15
16-23 24-31
… 72-79 80-87 88-95
0-7 0-7
Class I 128-bit Tag Memory Structure
The ID Code memory is address from left to right, where the leftmost bit (the
Most Significant Bit) is bit 0, and the rightmost bit (the Least Significant Bit) is bit
95. There is no restriction on the data that resides in this portion of the tag.
The Checksum is calculated over the 96 bits of the ID Code only. The checksum
is calculated and programmed into the tag automatically by the reader. This
checksum is calculated using the CCITT-16 standard.
The Lock and PassCode (PC) bytes stored at the end of tag memory are used to
lock a tag and kill a locked tag. Each of these codes takes exactly one byte. The
user can control the value of the PassCode, passing it in as a parameter to the
Lock command. The reader takes full control of the Lock byte, allowing it to flag
the tag as either locked or unlocked.
Summary of Contents for ALR-8780
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