R
EM4223
NOTES:
SIGNATURE value as sent by the tag to the Reader
as part of its transmission. In all other cases the
"Next_Slot" command will be accepted as
"Next_Slot (Not OK)".
Tags will automatically start a new round without a
"Begin_Round", "New Round", "Init_Round" or
"Init_Round_All" command when they receive a
"Next_Slot" or "Close_Slot" command while their
internal "Current Slot Counter" indicates the last slot
in the current round. This will also apply to tags
being moved from the ROUND_STANDBY state to
the ROUND_ACTIVE state by a "Next_Slot" or
"Close_Slot" command.
Commands marked with the "#" character will place
tags in the "ISO" mode of operation. These are the
"Begin_Round", "Init_Round"
commands.
& "Init_Round_All"
The "Wake_Up_FST" command marked with the
"@" character will place tags in the "FST" mode of
operation.
The last Mask selection made in the "ISO" mode
will be retained when switching from the "ISO" to
the "FST" mode.
"Next_Slot(OK)" will only occur when the tag
receiving the "Next_Slot" command receives the
command in the command window immediately
following its transmission to the Reader and if the
"Next_Slot" command contained the same
Tag state storage
Note: Implementation of the Quiet state storage may
imply that the Transponder will retain this condition
during a time greater than 2s, up to several minutes in
low temperature conditions. The Reset_to_Ready
command overrides the Quiet state under these
circumstances.
In the case where the Transponder loses the energizing
field for short periods of time (eg. when moving), the
Transponder retains its state for at least 300µs. In
addition, if the Transponder is in the Quiet state, it retains
its Quiet state for at least 2s.
State
Description
Commands to which responsive
The Transponder is out of the RF field
or the Reader Tx Carrier is switched
off.
RF field off
None.
The Transponder is in an RF field, its
clock is running and it is waiting for a
command.
Wake-Up_FST, Init-Round-All, Init-
Round, Begin-Round
READY
None required, responsive to all
commands according to the collision
arbitration loop. Standby_Round will
move the Transponder to the
ROUND_STANDBY state.
The Transponder steps through the
hold-off loop and will transmit if it has
reached its turn to transmit
ROUND_ACTIVE
Next-Slot, Close-Slot, New-round, Init-
Round, Init-Round-All, Begin-Round,
Reset-To-Ready, Wake-Up-FST &
Time-Out
ROUND_STANDBY
ROUND_ACTIVE state is suspended
The Transponder is unresponsive to
commands and the hold-off loop has
been suspended. It will only respond
QUIET (Persistent Sleep)
to a Reset-To-Ready command or will Reset-To-Ready
reset when removed from the RF field
for an extended period of time
typically greater than 2 seconds.
Table19 - Transponder States
24
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