Ti-RFID basic principle
TI * RFID is the referusion of the US Texas Instrument Corporation (TI) RFIT (RFID), due to its high reliability and good technical secondary development environment, now in numerous applications such as postal, freight, logistics, intelligent buildings and The community property management, road traffic, industrial production line, and animal minced industry are widely used.
1. Ti * RFID technology system composition
Ti * RFID IC card technology is a contacted card mode of the radio frequency range from low frequency to high frequencies, induced distance from near to high frequencies, and the product form is diverse, suitable for different fields. TI * RFID basic sensing system works in the way of the following figure:
Basic Ti * RFID systems consist of three parts: transponder, antenna (antenna), and RF signal processing control system (Reader) section. Wherein, the Reader section can include: RF processing module RFM, control module CTL, and upper host system (application software system part). The control module mainly includes data communication processing, an external input and output interface. The front-end device mainly completes the automatic capture of card data, and the host part mainly completes the management of system applications.
2. Signal data transmission mode
RF transmission section:
Between the inductor (IC card) and the Reader (RF module), the data (digital bits) in the inductor (digital bits) in the inductor are 124.2 and 134.2 kH2 by FSK modulation by an FSK signal RF transmission mode of 124.2 kH2 to 134.2 kH2. The two signals are transmitted in their way as follows:
Data communication method:
There are three RS232 / RS485 / RS422 in the transmission mode between the low-end device (Reader Data Acquisition) and the upper main control system (computer); in a specific system, it can be selected according to the actual situation.
3. Low frequency system workflow
a. Card charging process
Due to the low frequency system, the card is driven from the battery, and its work is supplied over the rechargeable pulse generated by READE through the RF mode. From the card structure analysis, a charging mechanism in the card is at work, and reader first transmits a certain amount of RF pulse signal, charging the card on the card, and then the card capacitance is discharged for internal circuitry.
b. Data capture
After the card is charged, start working, transmit card information and data at 124.2kHz and 134.2kHz FSK signals, and receives and demodulates the processing of subsequent devices to process digital signals through the antenna by the Reader RF module.
c. Data Transmission and Processing
The 9 data formed after the FSK signal demodulation is the card memory information, by the control module, and the upper control host is systematically applied in accordance with a certain communication protocol. After the upper host processing, the command will be given to the control module, and the output control information completes the predetermined function to the actuator.
