The worldwide ISO Organization ( International Standardisation Organisation), created a work group in 1991 ( WG3/SC19/C23) formed by manufacturers, technicians and researchers about the issue, with the aim of to uniting technologies and making possible the universalisation of electronic identification.
As a result of this, ISO WG3 of electronic identification published a standard first approved in March 1994 (ISO 11784), setting out the main structural characteristics of the Electronic Code of electronic identification for farm animals.
With this structure we set up the position and the bits number of the information telegram, with a total length of 64 bits, giving more than 274.000 millions of possible combinations of the identification code.
For the animal EID the unique frequency assigned to ISO 11784 fully valid since October 1998, is 134,26kHz or “animal EID ISO frequency”
It can be distinguished by two fundamental methods in radio frequency:
· FDX method (full duplex) allows a simultaneous communication between the transceiver and the transponder or chip
· HDX method (half duplex)(patent owned by Texas Instruments Ltd. Holland), alternatively uses a channel that allow an alternative communication (one way) between the transceiver and the transponder.
Both systems at first sight, seem to be equivalent. FDX should be quicker than HDX but in fact, the first ones seem to be more sensitive to interferences since it can use modulation systems according to width, or frequency variation in a wide range of frequencies.
However, HDX only uses phasyc modulation in the transmission of information and it does it in a tight range of frequencies.
These technical concepts , together with the terminology to use in the EID of animals by radio frequency, were discussed in another ISO standard approved in 1995 (ISO 11785).
Within it there are defined the characteristics that are to carry out all transceptors.