ISO 11784 & 11785

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ISO 11784 & 11785 are international standards that regulate the radio frequency identification (RFID) of animals, which is usually accomplished by implanting a microchip into just under the animal's skin.

RF identification of animals requires that the bits transmitted by a transponder are interpretable by a transceiver. Usually the bit stream contains data bits, defining the identification code and a number of bits to ensure correct reception of the data bits. ISO 11784 specifies the structure of the identification code. ISO 11785 specifies how a transponder is activated and how the stored information is transferred to a transceiver (the characteristics of the transmission protocols between transponder and transceiver)

These standards are updated and expanded in ISO 14223/1 which regulates "advanced" transponders for animals.

Contents

[edit] Introduction

The technical concept of animal identification described is based on the principle of radio-frequency identification (RFID). ISO 11785 is applicable in connection with ISO 11784 which describes the structure and the information content of the codes stored in the transponder.

The International Organization for Standardization (ISO) draws attention to the fact that compliance with clause 6 and Annex A of this International Standard may involve the use of patents concerning methods of transmission.

The ISO standards have severe limitations [1]. One of the objections is that the uniqueness of the ID is not guaranteed.

[edit] Specifications

[edit] RF Protocol

The carrier frequency for animal identification is: 134.2 kHz. There are 2 protocols in use to communicate between tag and reader:

Protocol Full Duplex (FDX or FDX-B) Half Duplex (HDX)
Modulation ASK FSK
Frequency 129-133.2 kHz 124.2 kHz=1
135.2-139.4 kHz 134.2 kHz=0
Channel code Differential Biphase none
Symbol time 0.23845 ms 0.1288 ms 1
0.1192 ms 0
Telegram (bit) 128 112

In DBP a 1 encoded as 00 or 11 and a 0 is encoded as 01 or 01, such that there is at least one transition per bit (so 11 is encoded as 0011 and not as 0000 or 1111)

[edit] Code Structure

ISO 11784:1996 Radio-frequency identification of animals - Code structure Published. The first 3 digits of the ID are the manufacturer code

[edit] HDX

With half duplex, the tag starts transmitting when the activating field is switched off. This makes the receiver simpler, as it is not necessary to pick up the weak signal from the tag among the strong activating field. The disadvantage is that the tag only has available to it the energy stored in a small capacitor to transmit.

Telegram layout:

  • 8 Startbits 01111110,
  • 1 Animal-No animal indicator,
  • 14 'Reserved for future use'bits,
  • 1 Extra data indicator bit,
  • 10 Country code according to ISO 3166,
  • 38 ID bits,
  • 16 CCITT CRC over the previous 64 bits,
  • 24 Application bits,

[edit] FDX

  • 11 Startbits 00000000001,
  • 38 ID bits,
  • 10 Country code according to ISO 3166,
  • 1 Extra application bits,
  • 15 Reserved bits,
  • 1 Animal bit,
  • 18 CCITT CRC over the previous bits, with the 9th and the 18th bit of the CRC set to 1,
  • 24 Application bits

[edit] Patents

Compliance with the standards may require use of techniques which are covered by (or claimed to be covered by) certain patents. ISO takes no position concerning the evidence, validity and scope of these patent rights.

The following patent holder has assured ISO that he will not exert its patent rights concerning FDX B technology:

The following patent holders have assured ISO that they are willing to negotiate licenses under reasonable and non-discriminatory terms and conditions with applicants through the world. In this respect, the statement of the holders of these patent rights are registered with ISO:

Attention is moreover drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights other than those identified above. ISO shall not be held responsible for identifying any or all such patent rights. In that connection, additional correspondences were received from two other companies (AVID and EID) not willing to forward pertinent declaration in accordance with the current ISO Directives.

Copies of declarations and statements received from all the above mentioned companies are available upon request to the ISO Central Secretariat.

[edit] References

  1. ^ www.rfidnews.com

[edit] External links