RFID Communications

6.4.11 ABxS Command 83H: Start/Stop Continuous SN Read All

DESCRIPTION

Command 83H starts and stops continuous read all mode for multiple tags. It reads the serial number and tag data. If the read length is zero (0), then only the tag's serial number is read. While in this mode, any other command can be issued and will be handled properly. After processing the new command, the controller resumes the continuous read. Continuous SN Read All is started or stopped by the start/stop byte in the command. A one (1) in the Start/Stop byte starts the continuous read and a zero (0) stops continuous read. The command has a parameter, Repeat Count, that can prevent multiple reads of the same tag. A tag is not read a second time until this specified number of tags have been read since it was last read. Allowed values are from 0 to 255, where 0 means the tag can be re-read anytime. When Start/ Stop Continuous SN Read All is interrupted with any other command, the repeat count is stopped during execution of the other commands and then resumed. The Reader/Writer responds with an acknowledge packet followed by data packets for each tag read.

Field

Remarks

Command

Command number in hex preceded by AAH

 

 

Family ID

Tag Family ID - 00H = all tags

 

 

Reserved

00H

 

 

Start Address

Tag address for the start of the read

 

 

Read Length

One word for the number of bytes to be read.

 

 

Repeat Count

Number of tag that must be read before the same tag will be read again (0-255)

 

 

Start/Stop

0001H to start, 0000H to stop

 

 

Message Terminator

FFFFH

 

 

Example

This example starts a continuous read of three bytes starting at address two, has a repeat count of four, and a family code of zero.

Command from Host

MSB

LSB

Remarks

AAH

83H

Perform Command 83

 

 

 

00H

00H

Tag Family 00/Reserved Byte

 

 

 

00H

02H

Start Address

 

 

 

00H

03H

Read Length of the data bytes

 

 

 

00H

04H

Repeat count

 

 

 

00H

01H

Stop/Start continuous read. This is to Start

 

 

 

FFH

FFH

Message Terminator

 

 

 

Response from Controller

MSB

LSB

Remarks

AAH

83H

Command Echo

 

 

 

FFH

FFH

Message Terminator

 

 

 

After the controller sends the acknowledgement, it sends the data read from the tags in the field.

MSB

LSB

Remarks

AAH

83H

Command Echo

 

 

 

00H

1EH

Serial Number byte /Tag 1

 

 

 

00H

94H

Serial Number byte /Tag 1

 

 

 

00H

0BH

Serial Number byte /Tag 1

 

 

 

00H

01H

Serial Number byte /Tag 1

 

 

 

LRP2000 Passive Reader/Writer

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Escort LRP2000 manual ABxS Command 83H Start/Stop Continuous SN Read All, 1EH, 0BH