RFID Communications

6.4.14 ABxS Command 86H: Write All

DESCRIPTION

Command 86H writes data to all RFID tags, or all tags with the same Family ID.

DISCUSSION

This command is used to write segments of data to contiguous areas of tag memory. It is capable of transferring up to 1 kByte of data from the Host with one command. The timeout value is given in 1 ms increments and can have a value of 001EH to FFFEH (65,534 ms). When the timeout is set to 0, the controller returns a syntax error. The Write consists of a Tag Family ID and an Reserved Byte, start address followed by the data stream to be written to the RFID tag. If the write range exceeds the last tag address, the controller returns error message 21H, invalid format. The data to be written to the tag is contained in the LSB of the register, and the MSB is always 00H. The controller returns a response when the timeout expires. The controller returns a response when the timeout expires.

Field

Remarks

Command

Command number in hex preceded by AAH

 

 

Family ID

Tag Family ID - 00H = all tags

 

 

Reserved

00H

 

 

Start Address

Tag address where the write will start

 

 

Write Length

Number of tag addresses to be written to in bytes

 

 

Timeout

Timeout value given in 1 ms units (001EH - FFFEH)

 

 

Write Data

Data to be written

 

 

Message

Terminator FFFFH

 

 

Example

Writes four bytes of data, starting at address 0001H. A timeout of 2 seconds (07D0H = 2000 x 1 ms increments) is set for the completion of the Write. The Family ID byte is set to 2, so all tags with Family ID of 2 are written to (four tags in this example).

Command from host

MSB

LSB

Remarks

AAH

86H

Perform Command 86

 

 

 

02H

00H

Tag Family/Reserved

 

 

 

00H

01H

Start Address

 

 

 

00H

04H

Write Length

 

 

 

07H

D0H

Timeout

 

 

 

00H

40H

Data byte 1

 

 

 

00H

41H

Data byte 2

 

 

 

00H

42H

Data byte 3

 

 

 

00H

43H

Data byte 4

 

 

 

FFH

FFH

Message Terminator

 

 

 

Response from controller

MSB

LSB

Remarks

AAH

86H

Command Echo

 

 

 

04H

08H

Ntags/Status

 

 

 

FFH

FFH

Message Terminator

 

 

 

75

LRP2000 Passive Reader/Writer

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Escort LRP2000 manual ABxS Command 86H Write All