RFID Communications
59 LRP2000 Passive Reader/Writer
6.4 Standard ABx Protocol

The ABx standard is a binary protocol, word (2-byte) oriented, so the syntax table reports the most

significant byte (MSB) and the least significant byte (LSB). In the serial transmission, the MSB is

transmitted first.

Table 17: Single Tag Example

Field Number
of Bytes Content
Header 1 AAH
Command 1 Command Code
Start Address 2 One word gives the first byte of tag memory to be accessed
Number of Bytes 2 One word gives the number of contiguous bytes to be accessed. Not used on 07H,
08H, 14H, 16H
Block Addresses 2 The first byte gives the address of the first block. The second byte gives the
number of blocks to be interrogated. Only used with command 14H
Timeout 2 0001H to FFFEH milliseconds
Data varies Data that is written to a tag. Each byte is included in the LSB of a two-byte word
Terminator 2 FFFFH

Table 18: Multi-tag Example

Field Number
of Bytes Content
Header 1 AAH. Always the MSB of the first word of an ABX Standard command
Command 1 Command Code - LSB of the first word
Family code 1 00H to address all tags in field
Reserved 1 Reserved for future use, set to 00H
Start Address 2 One word gives the first byte of tag memory to be accessed
Number of Bytes 2 One word gives the number of contiguous bytes to be accessed. Not used on
commands 87H, 88H, 91H, 8BH, 8CH
Block Addresses 4 The first word gives the address of the first block. The second word gives the
number of blocks to be interrogated. Only used with command 91H
Timeout 2 0001H to FFFEH milliseconds
Data varies Data that is written to a tag. Each byte is included in the LSB of a two-byte word.
Terminator 2 FFFFH