Unique 125 kHz - RFID standardConstantly developed RFID (Radio-frequency identification technology – radio identification) has been developed during the World War II. Its predecessor, IFF (Identification Friend or Foe) has been developed to determine, if the airplane was a friend or an enemy unit.
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For commercial purposes, RFID technology was first used in the 1950s and 1960s in the shoplifting prevention systems. It is currently used to protect various articles with stickers featuring a magnetized metal which activates the EAS gates at the store entrance.
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RFID reads data stored in the tag/ID memory. The tag may be a key fob or a standard credit card sized device (Fig. 1) with an electronic circuit embedded in a plastic, flexible housing protecting it against liquids and mechanical damage.
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Fig. 1. Example Unique 125 kHz proximity ID
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Unique 125 kHz is an RFID standard for transmitting/receiving data via radio waves at 125 kHz carrier frequency. Data exchange does not require optical visibility of the proximity card and the proximity reader, required by the barcode systems.
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For a wireless data transfer, a Unique proximity card should include the following (Fig. 2):
1. integrated circuit with ROM for storing data, i.e. a unique ID, 2. antenna – for wireless data communication.
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Fig. 2. Unique 125 kHz proximity card design |
| 1 - Integrated circuit with ROM 2 - Antenna |
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The following six components are part of the data transmission process in RFID technology (Fig. 3):
1. Proximity reader – supplied with 9–15 V DC (standard 12 V DC) or via a USB port.
2. Receiving-transmitting antenna – generating an electromagnetic field; usually a built-in antenna.
3. EM field – generated by the antenna, directly affects the active proximity card distance - up to 15 cm.
4. Proximity card – a passive tag operating at Unique 125 kHz standard; when the ID is within the reader's range, an electromotive force is induced to supply the tag.
5. Transferring data – e.g. a unique number, from the card to the reader's receiving antenna.
6. Receiving data and further data processing by the primary systems - e.g. to record employee hours, open gate/door, record total number of hours per day/week.
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Fig. 3. Unique 125 kHz system diagram |
| 1 - Proximity reader 2 - Antenna 3 - EM field 4 - Proximity card 5 - Transmitting data 6 - Receiving data |
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A Unique standard frequency directly affects the data reading distance - at 125 kHz, the maximum data reading distance is 15 cm. A maximum proximity reader range must also be considered when calculating the range of a complete system.
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Unique 125 kHz standard features 64-bit ROM (Read-Only Memory). The proximity cards are factory programmed. In theory, 64 bits allows to write 264 = 18 446 744 073 709 600 000 unique number.
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Unique 125 kHz proximity card applications:
– work supervision (access control, work hours monitoring, employee identification, room security),
– logistics (process improvements: device identification, logistic process tracking, storage, stock taking ),
– industry automation (component and intermediate product identification),
– theft protection,
– agriculture (animal identification, breeding place and owner allocation).
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Pros
– Very simple and very effective system.
– Proximity cards and key fobs protect the internal circuits against liquids and mechanical damage.
– RFID advantage over the barcode systems - visual contact between the card and the reader is not required and allows data transmission without taking the ID out of the handbag/backback.
– We offer programmable tags.
– Selected proximity readers can also process data, e.g. to calculate time spent by the employee at work.
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Cons
– Considering the number of manufactured cards, the individual card numbers can be duplicated.
– No security/encryption of data stored in the tag memory may allow an unauthorized person to copy (duplicate) the proximity card - by simply writing down its identification number.
– When two Unique cards are present near the proximity reader, none will be read, since the cards will interfere with each other (new standards are available, e.g. HITAG including anti-collision algorithm to allow reading several cards simultaneously).
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