What’s the Definition of APDU Command for Credit Card Reader
APDU: Application Protocol Data Unit--Application Protocol Data Unit. Protocol Data Unit (PDU) refers to the unit of data passed between peers. The protocol data unit (ProtocolDataUnit) physical layer PDU is a data bit (bit), the data link layer PDU is a data frame (frame), the network layer PDU is a data packet (packet), and the transport layer PDU is a data segment (segment) ), other higher level PDUs are data.
Application Protocol Data Unit (APDU) Transmission Protocol Data Unit (TPDU) IC cards are becoming more and more widely used. From memory cards to logical encryption cards, CPU cards have gradually dominated applications. CPU cards can be divided into two types according to the communication protocol: contact type and contactless type. The contact CPU card mainly uses two communication protocols: T=0 and T=1 communication protocol. T=0 is an asynchronous half-duplex character transmission protocol, and T=1 is an asynchronous half-duplex block transmission protocol. At present, the T=0 communication protocol is widely used, and most CPU cards at home and abroad support the protocol, and this communication protocol is also adopted in financial transactions.