HID Global Corporation 5553 Manuale Utente

1508-USM-00-0-04

HF Multi ISO RFID Reader User Manual, Firmware V1.4

2.3.5 ‘t’ Command – Data Frame Transfer

This command allows card-specific communication. The tag type has to be specified first – see
Set tag type, page 53.

Then issue a high-speed select command. If successful, the frame waiting time (FWT) is
calculated as defined in ISO14443-4, and used instead of the TMR timer if the Extended Protocol
flag is set – see Extended Protocol (default 1), page 27. If no FWT is found, TMR is used by
default.

Other considerations when using the ‘t’ command

Extended Protocol Flag – bit 6, Protocol configuration 1 register

This flag switches ISO14443-4 handling, including error handling, on or off.

ISO14443-4 Error handling – bit 7, Protocol configuration 2 register

This flag switches ISO14443-4 error handling on or off. Error handling always uses the
TMR time-out. The Extended Protocol Flag (above) has to be selected for Error Handling
to work.

Receiving more than 256 bytes

The PCB byte of ISO 14443-4 frames contains a chaining bit. This bit is set or has to be set
if the number of data does not fit in a single block. Refer to ISO 14443-4 for more detailed
information about the chaining mechanism.

Huge Data Mode

In huge data mode the option and length byte of the transfer data command will be turned
off to enable larger data transmission. A default value of 0Fh for the option byte will be
used. The full 512 byte data buffer is used in this mode, enabling chaining up to 512 data
bytes. In this mode, the answer comprises two length bytes (16bit) followed by the card
response. If using ASCII mode, a trailing <CR> byte is mandatory.

‘t’ command

Command

Data

Normal mode

't'

Downlink length (1 byte) <> 0
Option byte (1 byte)
Data (n bytes)

or

Transmit/Receive mode

Downlink length (1 byte) = 0
Downlink length new (1 byte)
Option byte (1 byte)
Transmit byte (1 byte)
Receive byte (1 byte)
CRC Preset LSB (1 byte)
CRC Preset MSB (1 byte)
Data (n bytes)

Page 90 of 144

August 2010