R
EM4223
number of successful reads, the round size should be
increased. As the proportion of white space increases in
proportion to the number of successful reads the round
size should be decreased.
Use of the round_size function (ISO & FST modes)
To optimized the system for the Transponder population
size, the Reader is able to send round size commands to
the
Transponder
by
way
of
INIT_ROUND,
INIT_ROUND_ALL, BEGIN_ROUND, NEW_ROUND and
WAKE_UP_FST commands. The Reader needs to
determine the proportion of collisions occurring and the
amount of white space occurring and accordingly adjust
the round size. As collisions increase proportional to the
The round size is coded in the INIT_ROUND,
INIT_ROUND_ALL, BEGIN_ROUND, NEW_ROUND and
WAKE_UP_FST commands using 3 bits according to
Table20.
Value
Bit coding
Round Size
MSB
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
LSB
'0'
1
'1'
'2'
'3'
'4'
'5'
'6'
'7'
8
16
32
64
128
256
RFU
Table20 - Round size coding
27
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