chrispeng [ad_1]
principle
After the tag enters the magnetic field, it receives the radio frequency signal sent by the reader, and uses the energy obtained by the induced current to send out the product information (Passive Tag, passive tag or passive tag) stored in the chip, or actively send a signal of a certain frequency ( Active Tag, active tag or active tag); after the reader reads and decodes the information, it is sent to the central information system for relevant data processing.
RFID technology realization analysis
1) Use UHF technology to achieve
When the personnel are not very dense, the area is relatively wide, the tags will not be blocked by other personnel (such as personnel entering the attendance area in turn), and when the cost is more sensitive, 915MHz RFID can be used, which has the following advantages:
* Realize long-distance card reading, according to different models of products, 0-10 meters of label information can be read, so as to realize long-distance automatic attendance;
* The label is light in weight, and employees can wear it by tagging;
* The label adopts passive design and has a long service life;
* There are many kinds of tags and the cost is low;
* The reader has strong anti-collision capability and can identify multiple tags at one time.
The reading distance can meet the requirements, but UHF has drawbacks. When the UHF tag worn by the worker is blocked, the reading may be missed.
2) Use 2.45GHz technology to achieve
When the application is crowded with people and the tag will be hidden by the human body, 2.4GHz or 433MHz RFID can be used. This system has the following advantages:
* The tag is powered by a battery, and the distance it can be recognized by the reader is longer, and it can be adjusted from 0 to 100 meters;
* Strong penetrating ability, little influence from being blocked by the human body, the label can be placed in the bag, pocket, etc.;
* Strong anti-collision ability, can identify more than 500 tags at a time.
The distance can be adjusted from 0-100m, and the distance can be flexibly controlled by the on-site situation. The active tag worn by the worker is in the reading area of the reader, as long as it is not
It is sealed with an all-metal shielding box, which can be identified.
RFID equipment recommendation
1) RFID reader
Install a reader on each side of the door, as shown in Figure 1.
Figure 1 System topology diagram
2) RFID card issuing machine
Realize short-distance authorization management, which can be uploaded to the software or super terminal through the serial port, without manually inputting the ID number, reducing labor costs and reducing manual misoperation.
3) Label
The label is the size of a bank card, and each worker is required to add a holster to the label. The method of wearing the chest will not affect the work of the workers, and it can also achieve a good monitoring of the workers’ entering and exiting the ship.
[ad_2]
