This command sends APDUs to the currently selected card. APDUs are the communication units between a reader and an ISO 14443-4 card. They're defined in the ISO/IEC 7816-4 standard. VHL.ExchangeAPDU transmits the actual APDU command via the Cmd parameter and returns the APDU response as Resp.

Keep an eye on the frame size

The combined size of transmitted and received APDU data (i.e. the combined size of Cmd and Resp ) must not exceed the maximum frame size supported by your reader's firmware version. To check the maximum frame size, run Sys.GetBufferSize and refer to the TotalSize response value.

For larger amount of data, please use VHL.ExchangeLongAPDU instead.

No error correction or retry mechanisms

The reader firmware does not perform any error handling operations with ISO/IEC 7816-4 inter-industry commands. Errors will be directly reported as part of the Resp value without further action, so you have to take care of error handling in your application.


Parameters (request frame)

Name Type/Size Description
AssumedCardType Enumeration (8 bits)

Forces the reader to assume a certain card type. By default (i.e. if CardType is 0x00), the reader uses the card type detected by VHL.Select.

  • Default (0x00)
    See description above
  • MifareClassic (0x10)
    MIFARE Classic (1k and 4k variants)
  • Iso14443aGeneric (0x11)
    Generic ISO 14443-4 Type A without ISO 7816-4 support
  • Iso14443aInterIndustry (0x12)
    ISO 14443-4 Type A compliant with ISO7816-4 and MIFARE L3
  • MifareUltraLight (0x13)
    MIFARE Ultralight
  • MifareDesfire (0x14)
    MIFARE DESFire (2k, 4k, and 8k variants)
  • InfineonSle55 (0x15)
    Infineon my-d proximity (SLE55)
  • Iso14443aIntIndustryMif (0x16)
    ISO 14443 Type A (NXP SmartMX/inter-industry)
  • MifarePlusL2 (0x17)
    MIFARE Plus L2 (2k and 4k variants)
  • LEGICAdvantIso14443a (0x18)
    LEGIC advant ISO 14443 Type A
  • MifarePlusL3 (0x19)
    MIFARE Plus L3
  • LEGICPrimeLegacy (0x20)
    LEGIC prime; this is a legacy value - it has been replaced by LEGICPrime .
  • LEGICAdvantLegacy (0x21)
    LEGIC advant (ISO 14443 Type A/ISO 15693); this is a legacy value - it has been replaced by LEGICAdvantIso14443a and LEGICAdvantIso15693.
  • Iso15693 (0x30)
    ISO-15693-compliant label
  • LEGICAdvantIso15693 (0x32)
    LEGIC advant ISO 15693
  • Iso14443bUnknown (0x40)
    ISO 14443-4 Type B without ISO 7816-4 support
  • Iso14443bIntIndustry (0x41)
    ISO 14443-4 Type B with ISO 7816-4 support
  • IClassIso14B (0x42)
    iCLASS via standard-compliant ISO 14443 Type B protocol (Level 3 compatible)
  • IClassIso14B2 (0x50)
    iCLASS via proprietary ISO 14443 Type B protocol derivate (Level 2 compatible)
  • IClass (0x60)
    iCLASS via ISO 15693
  • Felica (0x70)
  • EM4205 (0x80)
    EM 4205/EM 4305
  • EM4100 (0x81)
    EM 4100/EM 4102
  • EM4450 (0x83)
    EM 4450
  • Pyramid (0x84)
    Farpointe Pyramid
  • HidProx32 (0x85)
    HID Prox32
  • Keri (0x86)
  • Quadrakey (0x87)
  • HidIndala (0x88)
    HID Indala ASP
  • HidAwid (0x89)
  • HidProx (0x8A)
    HID Proximity
  • HidIoprox (0x8B)
  • Hitag1S (0x8C)
    HITAG 1 or S
  • Hitag2M (0x8D)
    HITAG 2 Manchester
  • Hitag2B (0x8E)
    HITAG 2 Biphase
  • TTF (0x8F)
    Low-level card type/programmable decoder
  • STSRIX (0x90)
  • SecuraKey (0xA0)
  • GProx (0xA1)
  • HidIndalaSecure (0xA2)
    HID Indala ASP+
  • Cotag (0xA3)
  • Idteck (0xA4)
  • BluetoothMce (0xB0)
    Bluetooth MCE; Mobile Card Emulation over Bluetooth
  • LEGICPrime (0xC0)
    LEGIC prime
  • HidSio (0xE0)
    Abstract card type for reading SIO Elements
Length of Cmd Integer (16 bits) Length of Cmd in bytes
Cmd Raw data APDU command data

Returned values (response frame)

Name Type/Size Description
Length of Resp Integer (16 bits) Length of Resp in bytes
Resp Raw data APDU response data