Passive RFID tag

Abstract

The utility model discloses a passive RFID tag, an upper computer is connected with a reader-writer through a serial port line, the reader-writer is connected with a reader-writer antenna through a radio frequency line, the reader-writer antenna is in wireless communication with a tag antenna of the passive RFID tag through an air interface, the passive RFID tag comprises a plurality of RFID chips, each RFID chip comprises four pins, and the pins are connected with the reader-writer antenna. Wherein two pins are connected in parallel with a tag antenna, and the other two pins are connected with a pin which is connected with an external resistor to be measured. A conventional resistance measuring scheme needs a battery to supply power or a power line, and an RFID-based testing scheme does not need a power supply and can be used in places where wiring is inconvenient, such as an assembly line and a rotating scene. A conventional passive RFID tag cannot detect external analog quantity. The passive RFID tag of the utility model is connected with the pin through the pin, and is connected with an external resistor to be detected through the pin, so as to detect the external analog quantity.

Description

TECHNICAL FIELD

[0001] The utility model relates to radio frequency identification technology field, concretely relates to a passive RFID label. BACKGROUND

[0002] Radio Frequency Identification (RFID) technology, also known as wireless radio frequency identification, can identify specific targets and read and write related data through radio signals without establishing mechanical or optical contact between the identification system and the specific target. RFID technology is divided into three categories: passive RFID, active RFID and semi-passive RFID. Among them, passive RFID products develop the earliest, which rely on the electromagnetic energy sent by the card reader to work; Passive electronic tags do not have an internal battery, and when outside the reading range of the reader, the electronic tag is in a passive state, and when inside the reading range of the reader, the electronic tag extracts the power required for its work from the radio frequency energy emitted by the reader. Among them, the main component of the passive RFID tag is the rectifier circuit used to convert the received radio frequency signal into a direct current power supply. Passive electronic tags are the most mature in development and the most widely used in the market because of their simple structure, economy and practicality. For example, bus cards, canteen meal cards, bank cards, hotel access control cards, second-generation identity cards, etc. This is everywhere in our daily life, which belongs to the near contact type identification.

[0003] At present, the conventional resistance measurement scheme needs to be powered by a battery or have a power line, while the RFID-based test scheme does not need a power supply and can be used in places where wiring is not convenient, such as assembly lines and rotating scenes. However, the conventional passive RFID tag cannot detect external analog quantities. UTILITY MODEL CONTENT

[0004] In view of the deficiencies in the prior art, the utility model provides a passive RFID label, wherein an upper computer is connected with a reader-writer through a serial port line, the reader-writer is connected with a reader-writer antenna through a radio frequency line, and the reader-writer antenna is connected with a label antenna of the passive RFID label through air interface wireless communication. The passive RFID label comprises: a plurality of RFID chips, each RFID chip comprises four pins, two pins of which are connected with the label antenna in parallel, and the other two pins are connected with a pin, and the pin is connected with an external resistance to be measured.

[0005] Preferably, the passive RFID label comprises: four RFID chips, which are connected with the external resistance to be measured through a connector;

[0006] The pin of the first RFID chip is connected with the first pin and the second pin of the connector;

[0007] The pin of the second RFID chip is connected with the third pin and the fourth pin of the connector;

[0008] The third RFID chip connects the fifth pin and the sixth pin of the connector through the pin;

[0009] The fourth RFID chip connects the seventh pin and the eighth pin of the connector through the pin;

[0010] The first pin, the third pin, the fifth pin and the seventh pin of the connector are combinedly connected to one end of the external resistance to be measured;

[0011] The second pin, the fourth pin, the sixth pin and the eighth pin of the connector are combinedly connected to the other end of the external resistance to be measured.

[0012] Preferably, the external resistance to be measured comprises a two-wire resistance.

[0013] Preferably, the RFID chip is a KX2005X-BT model RFID chip.

[0014] Compared with the prior art, the utility model has the beneficial effects that:

[0015] The conventional resistance measurement scheme needs to be powered by a battery or a power line, and the RFID-based test scheme does not need a power supply and can be used in places where wiring is inconvenient, such as a flow line or a rotating scene. The conventional passive RFID tag cannot detect external analog quantities. The passive RFID tag of the utility model connects the pin through the pin, connects the external resistance to be measured through the pin, and is used to detect the external analog quantity. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A structure diagram of the passive RFID tag provided by the utility model is shown in the figure;

[0017] Figure 2 A working diagram of the passive RFID tag provided by the utility model is shown in the figure. DETAILED DESCRIPTION

[0018] To make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0019] The utility model will be described in further detail below in combination with the drawings:

[0020] As Figures 1-2As shown, the utility model embodiment provides a passive RFID label, host computer and reader are connected through serial port line, reader and reader antenna are connected through radio frequency line, reader antenna and passive RFID label's label antenna are through air interface wireless communication, passive RFID label includes: a plurality of RFID chip, every RFID chip includes four pin, wherein two pin parallel connection label antenna, other two pin connect insertion needle, insertion needle connects external resistance to be measured.

[0021] As Figure 1 As shown, passive RFID label includes: four RFID chips, through joint connection external resistance to be measured;

[0022] The insertion needle of first RFID chip connects the first pin and the second pin of joint;

[0023] The insertion needle of second RFID chip connects the third pin and the fourth pin of joint;

[0024] The insertion needle of third RFID chip connects the fifth pin and the sixth pin of joint;

[0025] The insertion needle of fourth RFID chip connects the seventh pin and the eighth pin of joint;

[0026] The first pin, the third pin, the fifth pin and the seventh pin of joint merge and connect one end of external resistance to be measured;

[0027] The second pin, the fourth pin, the sixth pin and the eighth pin of joint merge and connect the other end of external resistance to be measured.

[0028] In the utility model embodiment, the external resistance to be measured includes two-wire resistance.

[0029] In the utility model embodiment, the RFID chip is KX2005X-BT model RFID chip.

[0030] KX2005X-BT is an RFID chip that can measure external circuit conduction and disconnection, and the detection of external on-off is a rough range, usually between 2MΩ~3MΩ, and the utility model proposes a simple external detection resistance range scheme based on this.

[0031] As Figure 2As shown, the host computer installs custom software, and communicates with the reader. The software of the reader can communicate with the reader and process related commands, and is an industrial software. The reader is connected with the antenna, provides radio frequency energy to the RFID tag, and realizes wireless communication with the RFID tag. The RFID tag is activated after receiving the energy provided by the reader, and can parse the data sent by the reader. The RFID tag has an RFID chip, and each chip has four pins, two of which are connected to the tag antenna, and the other two are connected to the pin, and the pins connected to the pin can realize on-off detection.

[0032] As shown in Figure 1 , it is assumed that each tag has four chips, the antenna pins are connected in parallel, and the pin pins are independently connected out, so there are eight pins. The pin is externally connected with a two-wire resistance. The pins of the four chips are respectively connected to the H1 joint in the following manner: chip 1 (first RFID chip) corresponds to 1, 2 feet, chip 2 (second RFID chip) corresponds to 3, 4 feet, chip 3 (third RFID chip) corresponds to 5, 6 feet, and chip 4 (fourth RFID chip) corresponds to 7, 8 feet. R1 is an external resistance to be tested, and the 1, 3, 5, 7 pins of the H1 joint are combined and connected to the 1 pin of R1, and the 2, 4, 6, 8 pins of the H1 joint are combined and connected to the 2 pin of R1. In this way, the test pins of the four chips are connected in parallel to the two ends of R1, and the resistance range of R1 is tested by the reader reading the data of the four chips.

[0033] After the reader is turned on and detected, when the resistance connected outside the tag is less than a certain value, the tag returns 0000, and when the resistance connected outside the tag is greater than a certain value, the tag returns 0202, so as to judge the on-off of the external circuit. By increasing different resistances outside the tag, the resistance range of the external resistance can be counted. 0000 is initially sent by the tag, sent to the reader through the UHF frequency electromagnetic wave, and then sent to the host computer by the reader. The reader can communicate with the host computer through a serial port or a network cable.

[0034] For example, as shown in Figure 1 , the resistance values outside the tag are 100KΩ (chip 1), 200KΩ (chip 2), 300KΩ (chip 3), and 400KΩ (chip 4), and the resistance to be tested is 2MΩ. The return value of chip 1 and chip 2 is 0000, and the return value of chip 3 and chip 4 is 0202, so the resistance range of the resistance to be tested is between 2.2MΩ and 2.3MΩ.

[0035] It should be noted that the number of external resistances is determined by the number of chips, and there are several external resistances for several chips. The number of resistances can also be expanded to be proportional to the number of chips, that is, one chip is associated with multiple resistances.

[0036] The above merely is preferred embodiment of the present utility model, and is not for limiting the present utility model, for the person skilled in the art, the present utility model can have various changes and changes. Any modification, equivalent replacement, improvement etc. that is made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A passive RFID tag, wherein a host computer is connected with a reader through a serial port line, the reader is connected with a reader antenna through a radio frequency line, and the reader antenna is connected with a tag antenna of the passive RFID tag through air interface wireless communication, characterized in that, The passive RFID tag comprises a plurality of RFID chips, each RFID chip comprising four pins, two of which are connected in parallel to a tag antenna, and the other two of which are connected to a pin, the pin being connected to an external resistance to be measured.

2. The passive RFID tag of claim 1, wherein, The passive RFID tag comprises four RFID chips, and the external resistance to be measured is connected through a joint; the pin of the first RFID chip is connected to the first pin and the second pin of the joint; the pin of the second RFID chip is connected to the third pin and the fourth pin of the joint; the pin of the third RFID chip is connected to the fifth pin and the sixth pin of the joint; the pin of the fourth RFID chip is connected to the seventh pin and the eighth pin of the joint; the first pin, the third pin, the fifth pin and the seventh pin of the joint are connected in combination to one end of the external resistance to be measured; the second pin, the fourth pin, the sixth pin and the eighth pin of the joint are connected in combination to the other end of the external resistance to be measured.

3. The passive RFID tag of claim 1, wherein, The external resistance to be measured comprises a two-wire resistance.

4. The passive RFID tag of claim 1, wherein, The RFID chip is a KX2005X-BT model RFID chip.

Images