set NFC shield to to emulate a ISO/IEC 1443-4A card

Hi guys, anyone has experience in setting pn532(NFC shield) to emulate a ISO/IEC 1443-4A card? My current working platform is arduino connects to NFC shield and use pn532.cpp and pn532.h library. As I try to set it following the introduction from NXP document PN532C106_Application Note_v1.2, the commend is
08 00
12 34 56
01 FE
A2 A3 A4 A5 A6 A7 C0 C1 C2 C3 C4 C5 C6 C7 FF FF
AA 99 88 77 66 55 44 33 22 11

it seemed that the command does not work because when I tried to send to NFC shield by sendCommandCheckAck(pn532_packetbuffer, 38)
it returns false

I have no idea to deal with it. Can you have solution to handle it? thank you.