User Guide

Table Of Contents
Allegro/Title-21 Tag Commands
63
Read Tag ID Single (21h)
The Read Tag ID Single/Tag Detect command performs a search operation and returns
the first Allegro/Title-21 tag it finds.
Read Tag ID Single Request Fields
Examples
An example, without TM Options, command:
Field Value Description
TM OpCode 0x21 TM OpCode
Timeout [2 bytes] Indicates how long the command should spend attempting
the operation, in milliseconds.
TM Options
Note: This and following
fields are optional.
Bit 4
(LSB=bit 0))
0 - Metadata flags must not be passed and Meta Data will
not be returned.
1 - Metadata flags must be passed and the corresponding
Metadata shall be returned with the tag EPC.
Metadata Flags (to specify
more than one OR the val-
ues together)
0x0000 When no flags are set no meta data will be returned, only the
tag EPC.
0x0001 When bit 0 is set the Read Count will be returned
0x0002 When bit 1 is set the LQI/RSSI will be returned
0x0004 When bit 2 is set the Antenna ID will be returned
0x0008 When bit 3 is set the Frequency will be returned
0x0010 When bit 4 is set the Timestamp will be returned
0x0020 When bit 5 is set the RFU (ThingMagic Only) will be returned
0x0040 When bit 6 is set the Protocol is returned.
FF 02 21 00 FA D6 1B
SOH Length OpCode Time-
out (ms)
CRC