R
EM4223
NEXT_SLOT
Acknowledges the successful reception of a
Transponder transmission by the Reader when
Acknowledges the successful reception of a
Transponder transmission by the Reader
valid ie. when received by a Transponder which when valid ie. when received by a
has just transmitted, and when the command is
received in the timing window and when the
Transponder which has just transmitted, and
when the command is received in the timing
Signature matches, causing the Transponder to window and when the Signature matches,
move from the ROUND_ACTIVE to the QUIET
states.
causing the Transponder to move from the
ROUND_ACTIVE to the QUIET states.
Causes a Transponder in the
ROUND_STANDBY state to move into the
ROUND_ACTIVE state.
Causes a Transponder in the
ROUND_STANDBY state to move into the
ROUND_ACTIVE state.
Causes the Transponder Current Slot Counter
to increment by one.
Causes the Transponder to automatically start
a new Round by resetting its Current Slot
Counter and randomly selecting a new Reply
Slot when the Current Slot Counter has
reached the Round Size Value.
CLOSE_SLOT
Causes a Transponder in the
ROUND_STANDBY state to move into the
ROUND_ACTIVE state.
Causes a Transponder in the
ROUND_STANDBY state to move into the
ROUND_ACTIVE state.
Causes the Transponder slot counter to
increment by one.
Causes the Transponder to automatically start
a new Round by resetting its Current Slot
Counter and randomly selecting a new Reply
Slot when the Current Slot Counter has
reached the Round Size Value.
STANDBY_ROUND
Causes the Transponder to move to the
ROUND_STANDBY state, in which the
Transponder does not transmit its identity or
data.
Causes the Transponder to move to the
ROUND_STANDBY state, in which the
Transponder does not transmit its identity or
data. While in the ROUND_STANDBY state,
the random number generator for slot number
choosing is running so that transponder slots
are not synchronized and thus have maximum
spread and randomisation in the Transmit
times. When the Transponder exits the
ROUND_STANDBY state, it will wait until the
next internally generated slot time before re-
enabling its data transmit circuitry.
RESET_TO_READY
Moves the Transponder from its current state to Moves the Transponder from its current state
READY state.
to READY state.
MUTE – this is not an actual
command but is an implied
command derived from the first
low-going pulse of any command.
Not used.
The Transponder will move to the
ROUND_STANDBY state upon reception of
the first low-going pulse of any command.
This could be any single pulse or the first
pulse of the SOF of a valid command. The
Transponder will continue to decode the
command and if the pulse turns out to be part
of a valid command, the Transponder will
move to either the READY or the
ROUND_ACTIVE state depending on the
actual command and the command
parameters. If the WUS bit = 0 the
Transponder will automatically leave the
ROUND_STANDBY state after a timeout
period of 2.5 X 176 tag bit periods has
elapsed since the last MUTE command (176
bits = maximum Data Message length).This
timeout will be reset each time a new implied
MUTE command is received.
Table 6– Command Operations
10
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