Hello @MIMIwho
AckReq is a Query command, recommended you could try the following steps to operate your tag. These steps initializes the RC663 to the ISO 18000-3 mode 3 protocol, sends an inventory request and listens to the response of a tag:
1: Cancels previous executions and the state machine returns into IDLE mode
2: Flushes the FIFO and defines FIFO characteristics
3: Fills the FIFO with 0x0E and 0x0E. (0x00 ISO 18000-3 - 21 Protocol in rx/tx direction)
4: Executes LoadProtocol command with parameters 0x0E and 0x0E (FIFO). This translates to load protocol ISO/IEC 18000-3 mode 3 - 212
5: Flushes the FIFO and defines FIFO characteristics
6: Switches the RF filed ON.
7: Clears all bits in IRQ0
8: Switches the CRC extention OFF in tx direction
9: Switches the CRC extention OFF in rx direction
10: Only the 7 last bits will be sent via NFC
11: Fills the FIFO with 0x04 (Performs a Query command AckReq of ISO/IEC 18000-3 mode 3)
12: Executes Transceive routine
13: Waits until a tag has responded by checking the IRQ0 register
14: Reads bytes from the FIFO to get tag ack.
Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.
Best regards,
Kelly
Technical Support
NXP Semiconductor
