RFID Communications

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

Content

of Bytes

 

 

 

 

 

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

Content

of Bytes

 

 

 

 

 

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

 

 

 

59

LRP2000 Passive Reader/Writer

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Escort LRP2000 manual Standard ABx Protocol, Single Tag Example, Multi-tag Example, Field Number Content Bytes