RFID Communications
77 LRP2000 Passive Reader/Writer
6.4.16 ABxS Command 88H: Tag Search All
DESCRIPTION
Command 88H checks to see if there is an RFID tag within range of the antenna.
DISCUSSION
This command activates controller to look for a tag in range. As soon as the controller finds a tag it returns
a command echo to the host. 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
number of tags returned can be either 1 (tag found), or 0 (timeout expired without having found a tag).
Example
Checks for an RFID tag in the RF field. A timeout of 1 seconds (07D0H = 2000 x 1 ms increments) is set for
the completion of the Tag Search. The Family ID is set for any tag. One tag is found and the command is
successful.
Field Remarks
Command Command number in hex preceded by AAH
Family ID Tag Family ID - 00H = all tags
Reserved 00H
Timeout Timeout value given in 1 ms units (001EH - FFFEH)
Message Terminator FFFFH
Command from Host Response from Controller
MSB LSB Remarks MSB LSB Remarks
AAH 88H Perform Command 88 AAH 88H Command Echo
00H 00H Family ID/Reserved 01H 08H Ntags/Status
07H D0H 2-second Timeout FFH FFH Message Terminator
FFH FFH Message Terminator