Communicating Directly with the reader

SCardControl function

Send commands directly to the reader through the SCardControl function. Set dwControlCode to SCARD_CTL_CODE(2048) and set lpInBuffer to the command you want to send to the reader.

The following piece of C code displays the string "hello!" on a GCR500 reader.

// Note that you might need to clear LCD first (command 2Ah)

dwControlCode = SCARD_CTL_CODE(2048);
memcpy(lpInBuffer, "\x2B\x81Hello!", 8);
nInBufferSize = 8;
nOutBufferSize = 300;

return_code = SCardControl(hCard,
                                            dwControlCode,
                                            lpInBuffer,
                                            nInBufferSize,
                                            lpOutBuffer,
                                            nOutBufferSize,
                                            lpBytesReturned);

if ((*lpBytesReturned == 1) && (lpOutBuffer[0] == 0x00))
   printf ("OK!\n");