Intermec IF2 Basic Reader Interface Programmer's Reference Manual (BRI version - Page 36

HEX(memory_bank:address, length), The EPCglobal Class 1 Gen 2 standard permits up to 66 bytes CRC-16

Page 36 highlights

Chapter 3 - Understanding BRI Programming Elements EPCID can also apply to UCODE119 tags from Phillips. The 12-byte EPCID is coded as described in the Phillips document, Implementation of EPC Tag Data on UCode EPC 1.19 Version 1.0 June 2004. The following rules apply to EPCID: • WRITE EPCID=HXXXXX is a shortcut for writing an EPC to a tag. • EPCglobal Class 1 Gen 2 defines memory in 16-bit words on even byte addresses. • The hex value must be one or more bytes. A typical EPCID is 12 bytes or 96 bits, but can be more or less than 12 bytes. • The header field is automatically calculated when using the EPCID keyword. The AFI flag and the 8 AFI bits are set to zero indicating that the tag format is now EPC. • For READ EPCID, the value returned is at least one byte. You can write data to the EPCglobal Class 1 Gen 2 tags EPC memory bank using: HEX(1:B, L) where: B is the byte offset into the memory bank. B must be even. L is the length. L must be greater than 1 and less than 67. The EPCglobal Class 1 Gen 2 standard permits up to 66 bytes (CRC-16, PC-16, 31EPC data words) in this bank but the tag manufacturer may supply less than 31 EPC data words. An attempt to write data beyond what exists in the tag results in a write error. You should be careful writing bytes 0-3 on a tag. Bytes 0-1 correspond to the CRC16. The tag recalculates the CRC-16 value each time the tag is powered on. Bytes 2-3 correspond to the protocol control (PC) word which includes the data length field, the EPC/ISO bit, and the header bits. You must be careful to encode the PC correctly. The data length field is the word count of the PC plus the EPC data words. An incorrect value written to locations 2 and 3 could render the tag unreadable until proper values are written to location 2 and 3. HEX(memory_bank:address, length) Data types declared as HEX can range in length from zero to the maximum tag address in length as specified by the length parameter. All HEX data types are represented as the hexadecimal characters (0 to 9, A to F). A unique feature of the HEX data type when used in a WHERE clause is the ability to use wildcard character pairs of ?? to represent a "don't care" condition. For details, see "READ" on page 54 and "WRITE" on page 69. Note: The wildcard notation cannot be used when the tagtype is set to EPCglobal Class1 Gen 2 tags. 24 Basic Reader Interface Programmer Reference Manual

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Chapter 3 — Understanding BRI Programming Elements
24
Basic Reader Interface Programmer Reference Manual
EPCID can also apply to UCODE119 tags from Phillips. The 12-byte EPCID is
coded as described in the Phillips document,
Implementation of EPC Tag Data on U-
Code EPC 1.19 Version 1.0 June 2004
.
The following rules apply to EPCID:
WRITE EPCID=H
XXXXX
is a shortcut for writing an EPC to a tag.
EPCglobal Class 1 Gen 2 defines memory in 16-bit words on even byte
addresses.
The hex value must be one or more bytes. A typical EPCID is 12 bytes or 96
bits, but can be more or less than 12 bytes.
The header field is automatically calculated when using the EPCID keyword.
The AFI flag and the 8 AFI bits are set to zero indicating that the tag format is
now EPC.
For READ EPCID, the value returned is at least one byte.
You can write data to the EPCglobal Class 1 Gen 2 tags EPC memory bank using:
HEX(1:
B
,
L
)
where:
B
is the byte offset into the memory bank.
B
must be even.
L
is the length.
L
must be greater than 1 and less than 67.
The EPCglobal Class 1 Gen 2 standard permits up to 66 bytes (CRC-16, PC-16, 31-
EPC data words) in this bank but the tag manufacturer may supply less than 31 EPC
data words. An attempt to write data beyond what exists in the tag results in a write
error.
You should be careful writing bytes 0-3 on a tag. Bytes 0-1 correspond to the CRC-
16. The tag recalculates the CRC-16 value each time the tag is powered on. Bytes 2-3
correspond to the protocol control (PC) word which includes the data length field,
the EPC/ISO bit, and the header bits. You must be careful to encode the PC
correctly. The data length field is the word count of the PC plus the EPC data words.
An incorrect value written to locations 2 and 3 could render the tag unreadable until
proper values are written to location 2 and 3.
HEX(memory_bank:address, length)
Data types declared as HEX can range in length from zero to the maximum tag
address in length as specified by the
length
parameter. All HEX data types are
represented as the hexadecimal characters (0 to 9, A to F).
A unique feature of the HEX data type when used in a WHERE clause is the ability
to use wildcard character pairs of
??
to represent a “don’t care” condition. For
details, see
“READ” on page 54
and
“WRITE” on page 69
.
Note:
The wildcard notation cannot be used when the tagtype is set to EPCglobal
Class1 Gen 2 tags.