RFID Interface
56
LRP820S-Series Long-Range Passive Reader/Writers
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ABxS Command 08H: Tag Search
DESCRIPTION
Check to see if there is an RFID tag in the field.
DISCUSSION
This command will activate the controller to search for the presence of
a tag within range of the antenna. If the controller finds a tag it will
return a command echo to the host. The timeout value is given in 1
msec increments and can have a value of 001EH to FFFEH (30 to
65,534 ms). When the timeout is set to 0, the controller will return a
syntax error. If no tag is present, it will return an error message. See
Section 6.2 for more information on error codes.
Field
Remarks
Command
Command number in hex
preceded by AAH
Timeout
Timeout value given in 1 ms
units (001EH - FFFEH)
Message Terminator FFFFH
Example
Checks for an RFID tag in the RF field. A timeout of 2 seconds
(07D0H = 2000 x 1 msec increments) is set for the completion of the
Tag Search.
Command from host
Response from controller
MSB LSB Remarks
MSB
LSB
Remarks
AAH 08H Perform Command 8
AAH
08H
Command echo
07H D0H Timeout Value
FFH
FFH
Message Terminator
FFH
FFH Message Terminator
