Disclosure of Invention
According to the problems existing in the prior art, the invention discloses a communication protocol based on a low-cost flexible printed label, which comprises the following steps:
a presentation layer for packing the data message and transmitting according to the data frame format;
receiving the data message transmitted by the presentation layer, and transmitting the data message of the presentation layer to establish a physical layer of a physical link;
the physical layer is located below the presentation layer.
Further, the frequency of the physical layer is 13.56MHz +/-7 kHz; the data rate of the physical layer is a self-adaptive data baud rate, and the range is as follows: 9600bps-38400 bps; the physical layer communicates in a load modulation mode, and the load modulation meets the requirements of the international standard ISO/IEC 10373-6; and the bit coding of the physical layer adopts NRZ-L.
Further, the presentation layer and the physical layer include:
an oscillator for generating a reference operating frequency fc;
the information memory is used for storing the label identity information, setting the switch display by adopting the identity information of the switch display label and ensuring the uniqueness of the identity code;
a frequency divider for dividing the reference working frequency transmitted by the oscillator to generate 5 groups of frequency division signals;
the encoder is used for 5 groups of frequency division signals transmitted by the frequency divider and the identity information of the label transmitted by the information storage;
and an antenna modulator for loading the signals transmitted by the encoder from the switch array to an antenna.
Further, the fields of the digital frame format of the presentation layer include: a sync word, identity information, a check word and an end word.
Further, the check word calculation method is as follows:
wherein: CS represents check word, and takes low 8 bits of data; n represents the number of bits of the UID.
A low cost flexible printed label comprising a communication protocol as claimed in any one of the preceding claims.
Due to the adoption of the technical scheme, the communication protocol based on the low-cost flexible printed label has the advantages that the flexible printed label using the communication protocol has low cost, so that large-scale application becomes possible, the flexible printed label using the simplified communication protocol simplifies a circuit, the precision requirement on production equipment is greatly reduced, the cost after the scale production is about 20 percent of that of a standard protocol label, various radio frequency electronic labels in the current market can be completely replaced, the communication protocol can be widely applied to various industries, and the communication protocol is particularly suitable for the application of cost-sensitive fast-consumption industries, such as beverage packaging, express packaging and the like; the method can realize low-cost object identification and lay a solid foundation for the interconnection of everything; one object can be realized, UID can reach 40BIT, codes can reach more than trillion, and the communication is stable and reliable; the protocol has self-adapting and checking functions and can be used in complex environment.
Detailed Description
In order to make the technical solutions and advantages of the present invention clearer, the following describes the technical solutions in the embodiments of the present invention clearly and completely with reference to the drawings in the embodiments of the present invention:
a low cost flexible printed label based communication protocol comprising:
a presentation layer for packing the data message and transmitting according to the data frame format;
receiving the data message transmitted by the presentation layer, and transmitting the data message of the presentation layer to establish a physical layer of a physical link;
the physical layer is located below the presentation layer.
The communication protocol is used for the label reader to correctly receive the identity information sent by the flexible printing label.
In addition, the communication protocol standardizes the energy and information interaction process and requirements between the reader and the flexible printed label.
FIG. 1 is a block diagram of a tag and reader of the present invention; each communication participant mainly performs the following functions:
flexible printed label: receiving energy from the reader → activating the tag circuit → reading the identity information of the tag → modulating the identity information to an antenna for transmission to the reader;
a tag reader: transmitting energy to the tag → receiving and demodulating the signal sent by the tag → analyzing the signal;
FIG. 2is a schematic diagram of a tag and reader communication according to the present invention;
further, the physical layer has the following characteristics:
the physical layer energy transfer: the reader should generate an RF field that gives energy;
frequency of the physical layer: the RF operating field frequency (fc) should be 13.56MHz + -7 kHz;
data rate of the physical layer: the self-adaptive data baud rate is in a range of 9600bps,38400 bps;
the reader automatically calculates the baud rate according to the received synchronous words;
the physical layer adopts load modulation, the tag can communicate with a reader through an inductive coupling area, and the load modulation meets the requirements of the international standard ISO/IEC 10373-6.
Representation and encoding of bits of the physical layer: the bit coding adopts NRZ-L;
the method for realizing the self-adaptive data baud rate of the physical layer comprises the following steps:
when the communication data frame is sent with the sync word 0XAA first, the sync word waveform is as shown in fig. 3, and the reader extracts the time length T of the sync signal after detecting the sync signal, the data baud rate can be calculated to be 1/(T/4).
Advantages of adaptive data baud rate:
the requirement on the reference oscillation frequency precision of the printed label can be reduced, the qualification rate of products is improved, and the cost is reduced.
Further, the presentation layer has the following characteristics:
the data frame format of the presentation layer is illustrated in the following table
Field(s)
|
Length of
|
Description of the invention
|
Synchronous word
|
1
|
Fixed to 0XAA
|
Identity information (UID)
|
5
|
Identity code of label
|
Check word (CS)
|
1
|
Verification
|
Ending word |
|
1
|
Fixed at 0X55 |
Examples of the data packet of the presentation layer are as follows:
the check word calculation method of the representation layer is as follows:
wherein: CS represents check word, and takes low 8 bits of data; n represents the number of bits of the UID.
Further, fig. 4 is a schematic diagram of a module at a tag end, where the presentation layer and the physical layer include: the system comprises an oscillator, an information memory, a frequency divider, an encoder and an antenna modulator;
the oscillator is used for generating a reference working frequency fc;
the information memory is used for storing label identity information, setting switch display by adopting the identity information of the switch display label and ensuring the uniqueness of identity codes;
the frequency divider divides the reference working frequency transmitted by the oscillator to generate 5 groups of frequency division signals f2, f4, f8, f16 and f32 (the number after f represents the frequency division number);
the encoder displays 5 groups of frequency division signals transmitted by the frequency divider and identity information of the label transmitted by the information storage through a switch;
the antenna modulator loads the signals from the switch array transmitted by the encoder onto an antenna.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.