Communicating Directly with the Reader

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.  Note that Gemplus EMV certified readers will not allow the use of this command.

The following piece of C code displays the string "hello!" on a Gcr500 reader.  Note that you install a Gcr500 as a Gcr410, by writing Gcr410 in the Reader Name box of RdrInstall.

// 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");