Card reader:

(1) is called POS terminal for short. The terminal dials through the telephone line to send the information to the UnionPay platform. After the platform of UnionPay recognizes the relevant information, it will send the deduction information to the issuing bank, and the issuing bank will send it back to the platform of UnionPay after confirmation. After confirmation by UnionPay, the processed information will be sent to the front-end terminal, and the terminal will print the documents after receiving the confirmation information.

(2) Mobile POS terminals, by the same principle, send and receive information through data signals. The communication fee is not much, and the fixed terminal communication fee is charged by the telecom company according to the local telephone standard according to the flow calculation!