User's Manual

MP9310 User’s Guide
38
Programming the Matrics Class 0+ Tag
Matrics Class 0+ tags utilize a process called Singulation. This is a process of
uniquely identifying a tag in a population of tags and retieving its Electronic
Product Code (EPC). For detailed information on EPC Class 0 singulation, refer to
the EPC Global Class 0 specification.
When a tag is requested to identify itself, it responds with different data based on
its singulation mode. Class 0 and Class 0+ tags allow three modes of singulation:
• ID2 - This mode responds directly with the EPC. ID2 is the fastest mode
(fewest bits transmitted), but requires the reader to echo the bits back to the
tag. This echo can create security issues. Also, this mode can not be read when
writing the EPC, since the echo will change the EPC as you write it.
• ID0 - This mode returns packets of 12 random bits that are different every time
you singulate. When the reader has what it determine is the correct number, it
writes the EPC. This mode is the only reliable method of writing the tag EPC.
• ID1 - This mode is the same as ID0, but every singulation returns the same bit
stream. The bits are random, but they are seeded from the EPC. Writing the
EPC changes these bits.
The singulation mode is controlled with the PE0 register and must be set prior to
writing tags.
Matrics Class 0+ tags contain three writable pages or memory blocks: These pages
are as follows:
• Page 0 – Kill code (24 bits)
• Page 2 – EPC code (64 or 96 bits)
• Page 3 – User data (104 bits)
When Page 2 or Page 3 data is written, a 16-bit CRC is appended.
Both the Wa and Wt command can be used to write Matrics Class 0+ tags. The
following command parameters are used:
• a: address block. This represents the memory page of the tag on which the
write operation will occur. Values can be 0, 2 or 3, as defined previously. If
this parameter is missing, it will default to 0.
• l: length. This parameter is required and is the number of bytes being written.
• b: write data. This parameter is required and contains the data to write.
• d: tag ID. This parameter is required for the Wt command (optional for Wa)
and specifies the EPC code of the tag to which the write operation applies. The
16-bit CRC must be supplied along with the 64 or 96 bit EPC code.