ThingMagic M5e-Compact - Manual (Page 83)

Application Tag Commands
Command Set 83
Read Tag Single (21h)
For deprecated version (including non-Gen2 protocol specific syntax) of this command
see Appendix D:
Read Tag Single (21h)
The Read Tag Single command will search for a tag for the specified timeout or a single
tag is found, whichever comes first. The search criteria is specified using the
Tag
Singulation Fields . If Option=0x00 is specified it will return with the first tag it finds,
otherwise it will only return Success and the found EPC if a tag matching the specified
criteria is found. If no tag is read, a fault code is returned.
In addition to the Tag Singulation Fields the basic Read Tag Single command takes a 16-
bit timeout value in milliseconds. The command will return after a tag is found or the
timeout expires, whichever happens first.
The basic syntax which returns only the tag EPC is defined in Get Tag EPC . With
additional Option bits set Read Tag Single can also return Tag Read Meta Data using the
syntax in Get Tag EPC and Meta Data .
Note
Read Tag Single will always use Gen2 Q=0 when Get Protocol Configuration
(6Bh) Q Value set to Dynamic Q. For use with large tag populations a Static Q
appropriate for the population should be used to avoid collisions.
Get Tag EPC
The following example shows a search requesting a tag matching the following criteria for
a max timeout of 1000 ms. This example uses the
Tag Singulation/Select Functionality with
Option=0x03, indicating Tag Selection based on the contents of User Memory,
specifically:
Memory Bank = User Memory.
Starting Address = bit 32
Select Data = 0x1234