What is RFID? RFID technology, equipment, tags, systems
RFID is a software and hardware complex consisting of:
radio frequency tag;
RFID tags are portable devices consisting of a receiver micro-antenna and a microcontroller. The main task of radio frequency tags is the storage and transmission of the code (identifier) programmed in the microcontroller.
RF tags can be classified as follows:
active and passive;
Active tags are equipped with a miniature battery that allows the tag to transmit information over long distances. Passive tags only work when there is a carrier frequency from an antenna causing induction on a micro antenna in the tag. radio frequency range;
There are several radio frequency tag operation ranges. The appearance of several bands is associated with a ban on the use of certain radio frequencies in various states.
data reception and transmission standard;
Currently, there are several data transmission standards in the world:
1) ISO 14443
2) ISO 15693
3) EPC / ISO 18000-6
4) ISO 10374
5) ISO 18000-4
RF tags can be made in the form of:
1) hard inserts;
2) paper labels.
The reliability of the tags is determined by the design. The main parameters are: protection from dust and humidity (IP), resistance to temperature effects.
Antennas are devices for emitting radio waves and receiving response from radio frequency tags.
Testing. Antenna on a tripod.
Testing. Antenna on a tripod and antenna below.
The receiver is a device for generating and receiving radio signals. A personal computer or computer network and antenna are connected to the receiver. Connection to a personal computer is carried out via standard RS232, USB or Ethernet interfaces.
RFID Receiver. 2 antennas are connected to it. Communication with the receiver via an access point.
Software is needed to write or read an identifier written on a radio frequency tag. The ID itself is a sequence of bytes. For the program, this sequence means practically nothing. The meaning of this sequence appears only with information about the object on which the label is set. Information about the objects is pre-entered into the database.
RFID technology application
Accelerating the identification of objects is required everywhere: in production, in a warehouse, in a store, on a highway, in a library, and so on. The general scheme for identifying objects using RFID is as follows:
In this case, the tags are located inside the equipment in the boxes.
Feasibility of using RFID
The use of RFID technology is advisable in the following cases:
The presence of the pipeline and a constant flow of objects that require accounting.
The presence of pallets, boxes or other objects that require consideration of the movement that are in constant rotation on the territory, for example, a warehouse or production.
The presence of packed boxes, folders with objects, information about which may be required during selection.
The presence of oversized transport: cars, trucks, loaders - in case of need to control their movement.
In most other cases, bar coding using simple labels is more appropriate than using RF tags.
RFID Application Features
RFID technology has a number of features that must be considered when designing an automated identification system:
short distance reading
When designing a system, it is necessary to calculate the distance from the receiver antenna to the possible location of the RFID tag. In practice, a stable reading is provided with a distance from 0.2 m to 1.5 m. To increase the distance to 3-4 meters, it is necessary to ensure the "direct visibility" of the radio frequency tag. RF tag cost spread
The cost of one radio frequency tag is from 0.5 Euro (paper label) to 5 Euro (solid label). Thus, the marking of objects that will soon leave the storage area, radio frequency tags costing more than 5 Euros is impractical. Marking the same objects that are in constant rotation in a warehouse or production, it is advisable tags of such value. These tags can be placed on pallets, boxes, shelves, etc. possible readout errors when working at the maximum distance or in the area of high radio frequency mark accumulation
It is important to take into account the peculiarity of reading radio-frequency tags: with an increased concentration of tags in one place, a reading error may occur. This error occurs when a concentration of more than 10 tags are located parallel to each other at a distance of less than 1-5 cm with a reading distance of more than 1 m. To increase the stability of reading, it is necessary to increase the time the tags stay in the reading area up to 5-10 seconds with slow progress of the marked object along the antennas.
Examples of RFID equipment design
Data collection terminal equipped with RFID antenna Antenna for RFID
RFID Receiver (connect up to 4 antennas)
10dB Antenna for RFID Receiver