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25 July 1996
2
Product Function
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2.1 Description
The Micro-reader module is an intelligent plug-in module which can be plugged into or soldered
onto an application specific adapter board. It supports serial data communications between a PC and
TIRIS transponders. With its Serial Communications Interface (SCI) the Micro-reader supports
TTL data communications, which with the addition of a communications driver (for example: RS232
or RS422) allows communication to a standard interface. The Micro-reader can be controlled
remotely by either providing certain inputs with the corresponding voltage level or sending
commands to the SCI. It can be driven either with or without synchronization - the synchronization
can be either wireless or wired to enable reliable operation in multi-reader environments. Two
outputs show the reader status and inform the user about a successful command execution. The
Micro-reader supports all available TIRIS transponders.
2.1.1 Power Supply
There are two separate 5V supplies to the Micro-reader, one for the output stage (VSP) and the
other for the logic (VSL). On power up VSL should rise faster than 0.1 V/ms to ensure a reliable
operation. The Micro-reader has an on-board reset circuit which will reset it should the supply fall
below 4 V (± 0.2 V).
In order to avoid problems with noise conducted via the supply lines, we recommend that if a single
supply is used, separate connections from a common de-coupling capacitor are used to feed the
Micro-reader.
Note:
The RF Module must not be supplied by Switched Mode Power Supplies (SMPS)
because most SMPS operate at frequencies around 50 kHz
generated field can interfere with the TIRIS receiver
power supplies, or SMPS with a fundamental operating frequency of 200 kHz or higher
2.1.2 Antenna
The Micro-reader has been designed for use with a 47 µH antenna with a Q of 10 to 20 at 132 kHz
to generate the exciter frequency of 134.2 kHz. Because of the low Q the system does not need to
be tuned.
Care must be taken when handling the Micro-reader as high voltages across the antenna pins
could be harmful to your health.
Therefore only use linear regulated
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WARNING
Micro-reader Module
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The harmonics of the
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This is
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