Io
SENSOR
Section 4 RF/ID Tag Reader
SMT-200 Operations and Technical Manual 2.00/R1
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4.1
RFID Tag reader introduction
When testing geophones strings using the SMT-200 a test identification or the string number must first
be allocated to each string test. This number can normally to be found as an ID label attached to the
string. The identification label has to first be located and the identification number then entered in to
the SMT-200 before commencing with the actual geophone string test. This is a time consuming
practice and is a possible source of errors.
However by using the RFID tag reader this process is much faster and it’s impossible to enter an
incorrect string number. Just point the tag reader at the tag, pull the trigger and it reads the string
number and automatically starts testing. Fast and error free.
4.2
Principles of the RFID Tag reader
The tag reader consists of a low power radio transmitter and receiver together with a microprocessor
for interpreting and conditioning the signals. The tag consists of an integrated circuit (IC) containing a
unique number and a wire antenna. Both are encapsulated in a small round epoxy package. This tag
can be attached to the string cable in a special ‘key-hanger’.
Activate the tag reader by pulling the trigger. A magnetic field is generated by a RF current passed
through its antenna.
When the reader is close enough proximity to the tag, a current is induced in it’s coil and the IC
continuously transmits it’s unique number back to the radio receiver in the tag reader until read.
The tag number is send via an RS232 link to the SMT-200.
Tag reader
SMT-200
String
key-hanger
A
B
C
