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May ’00
Chapter 2. Commands
Examples:
1. The command sequence 'X01' reads page 1 of a Multipage Transponder without
switching the TX/RX control outputs.
2. The command sequence 'XM4201' reads page 1 of a Multipage Transponder,
switching the control output lines for a 4 Channel Transmit Multiplexer and a 2
Channel Receive Multiplexer.
A typical Multiplexer read sequence selects the Transmit Antennas from 1 to
TX_ANT then the Receive Antennas are selected from 1 to RX_ANT with a succes-
sive transponder read.
The multiplexer sequence depends on how many transmit and receive antennas are
specified, but the sequence is always: The first TX antenna is selected, then in series
the RX antennas (1, 2, 3 or 4), then the next TX antenna is selected, followed once
again by the RX antennas. Then the next TX antenna and so on.
Example:
Comment
XM2407
Read page 7 of a multipage transponder us-
ing 2 TX and 4 RX antennas.
Sequence = TX Antenna 1
Read page 7
RX Antenna 1
Page 7 ID
RX Antenna 2
Page 7 ID
RX Antenna 3
Page 7 ID
RX Antenna 4
Page 7 ID
TX Antenna 2
Read page 07
RX Antenna 1
Page 7 ID
RX Antenna 2
Page 7 ID
RX Antenna 3
Page 7 ID
RX Antenna 4
Page 7 ID
XM2209
Read page 9 of a multipage transponder us-
ing 2 TX and 2 RX antennas.
Sequence = TX Antenna 1
Read page 9
RX Antenna 1
Page 9 ID
RX Antenna 2
Page 9 ID
TX Antenna 2
Read page 9
RX Antenna 1
Page 9 ID
RX Antenna 2
Page 9 ID
In order for the multiplexer to work correctly the I/O lines must be configured to be
outputs (the default status).