Texas Instruments HFDEMOKITII ユーザーズマニュアル

Field Name

SOF

Field Size 

1 byte

Field Value

01

hex

Purpose

Start of Frame

Field Name

Length

Field Size 

2 byte LSB first

Field Value

Packet dependent

Purpose

Describes the length of the whole packet including SOF

Field Name

Node Address

Field Size 

2 byte LSB first

Field Value

0000

hex

Purpose

always 0000

hex

Field Name

Command flags

Field Size 

1 byte

Field Value

Varies by command

Purpose

Specifies the action just taken by the reader

Field Name

Command

Field Size 

1 byte

Field Value

Varies by command

Purpose

Specifies the action just taken by the reader

Field Name

Data

Field Size 

0 to 23 bytes

Field Value

Command dependent

Purpose

Contains the parameters and data for the command just processed

Field Name

BCC

Field Size 

2 bytes

Field Value

16 bit LRC of the preceding packet including the SOF

Purpose

Allows the host to validate the correct reception of the response
packet

 

The command flags in the request packet control the actions of the reader. The meanings of the
bits are defined below.

Bits 0-3 

Reserved for future use and should be set to ‘0’ for upward
compatibility.

Bit 4 

Is the address flag and if set, the command is only performed on
transponders whose address matches the data section of the packet.

Bits 5-7 

Reserved for future use and should be set to ‘0’ for upward
compatibility.