CSL CS468 16-Port EPC CLASS 1 GEN 2 RFID READER
USER'S MANUAL, VERSION 2.0.1
Copyright © Convergence Systems Limited, All Rights Reserved
81
7.10
Target and Toggle A / B Flag (C# and Java Demo App)
There are 2 meanings for
Target
in the standard of
EPC
Radio-Frequency Identity Protocols
Class-1 Generation-2 UHF RFID Protocol for Communications at 860 MHz
–
960 MHz
by
EPCglobal
.
One of them is the parameter of RFID protocol
Inventory
–
Select
Command, which
indicates whether the Select command modifies a Tag's Selected (SL) flag or its inventoried flag.
Another
Target
is the parameter of RFID protocol
Inventory
–
Query
Command, which selects
whether Tags whose inventoried flag is
A or B
participate in the inventor round. Tags may change
their inventoried from A to B (or vice versa) as a result of being singulated.
In CSL RFID Reader Read / Write configuration,
Target
is the parameter of RFID protocol
Inventory
–
Query
Command. The options for Query Command in the field
Target
are
“A”
,
“
B
”
and
“
Unknown
”
. User can set the Target of CSL RFID Reader using both C# and Java Demo App.
Inventory contains a designation of the tags with which flag is to be inventoried. User can define
it to be Flag A, or Flag B. There is also a parameter toggle, if user set it to "on", i.e. toggle, then in
continuous inventory it will inventory Flag A in the first round, then Flag B in the next round, and
so on. If user set it to "off", then it will keep on inventorying the same flag.
So the usual trick is to set inventory to read Flag A, and toggle to off. Then it will keep on
reading Flag A tags. Those that have been read will become flag B and it will not respond to an
inventory of Flag A tags. This will the crowded situation will improve as reader read more and
more tags, leaving only those who have not been read yet (hence still in flag A state) to respond
with no jamming by others.
