SATO CL408E Guía Del Usuario

Descargar
Página de 51
 
Version 0.8 
 
 
 
21/10/2004 
 
 
    Page 16 of 44 
Specifications, standards, and terminology are continually updated. RFID systems must 
comply with all relevant regulatory requirements as local governments regulate allowable 
frequencies, power output, emissions, and other performance characteristics. RFID 
standards created by the International Organisation for Standardization (ISO) in Geneva 
meet all worldwide regulatory requirements, so users can be assured their systems are 
available for global use.  
 
Q: Will the tags work globally? 
EPCglobal is in progress with a goal and mission to establish a global standard for 
immediate, automatic identification of any RFID item in the supply chain of any company, 
in any industry, anywhere in the world. Additionally, different regions of the world have 
designated different frequencies for RFID; thus, tags that are able to handle a wider range 
of frequencies would have more global coverage. Additionally, UHF tags, despite the 
target design frequency, can be read by another UHF frequency (i.e. a 915 MHz tag can 
be read with an 868 MHz reader and vice versa) given that the reader can support the 
handling of multiple frequencies. However, a degradation of performance can be expected 
when using mismatched components. 
 
DIFFERENTIATION BETWEEN EPC TAG PROTOCOLS 
The current specifications of the EPC (Electronic Product Code) protocol are open 
standards with the intention of allowing any vendor to manufacture products to either one 
of these specifications. Unfortunately, these protocols are not interoperable. A single 
reader can't read all these tags unless it is a multi-protocol reader. While Class 0 and 1 are 
tag protocols, Class 2, 3, and 4 are not distinct protocols, but different configurations.
 
Differences lie in the following: 
 
 
Class 0 is a read-only tag, which is the simplest type of tag where the EPC data is written 
only once into the tag during manufacture, resulting in a unique ID number assigned only 
to that particular tag. The memory is then disabled from any further updates. Class 0 is 
also used to define a category of tags called EAS (electronic article surveillance) or anti-
theft devices, which have no ID, and only announce their presence when passing through 
an antenna field. 
 
 
There is a newer version of the Class 0 tag, the Class 0 plus, which can read and write, 
and in which the transponders generally provide a tamper-proof fix factory-set identification 
code. Other than the read-write capabilities of this tag protocol, the Class 0 plus tag is 
identical to the Class 0 tag. 
 
 
Class 1 is a read-write tag allowing the end-user to input any serial number. Both operate 
in the 860-950MHz frequency band. This offers advantages in many applications where