ib technology

5

Read Tag

Command to read 4 bytes of data from HT2 32 bit page. If the read was successful,

indicated by acknowledge status flags then four bytes of tag data follow.

B7

B0

Command:

0 1 0 1 0 0 1 0

(ASCII “R”, 0x52)

Argument1:

x x x x x N N N

(N = HT2 page address 0-7)

Acknowledge:

1 1 F F F F F X

(F = Status flags)

Data only follows if read was successful

Reply1:

D D D D D D D D

(D = msb data to write to HT2)

Reply2:

D D D D D D D D

Reply3:

D D D D D D D D

Reply4:

D D D D D D D D

(D = lsb data to write to HT2)

Note that PASSWORD exchange occurs for READ command.

If no tag present then acknowledge / status byte reply is 0xC0

If tag present but RWD PASSWORD check fails then acknowledge byte reply is 0xC0.

If tag present but TAG PASSWORD check fails then acknowledge byte reply is 0xC4.

If tag present and both PASSWORDS match then acknowledge reply is 0xD6 followed

by 4-bytes of data.

Tag STATUS

Command to return Tag status. The acknowledge byte flags indicate general Tag status.

B7

B0

Command:

0 1 0 1 0 0 1 1

(ASCII “S”, 0x53)

Acknowledge:

1 1 F F F F F X

(F = Status flags)

Card UID

Command to return card status and UID (Unique Identifier or Serial number).

The acknowledge byte flags indicate general Tag status.

B7

B0

Command:

0 1 0 1 0 1 0 1

(ASCII “U”, 0x55)

Acknowledge:

1 1 F F F F F X

(F = Status flags)

Data only follows if card was selected OK with no errors detected.

Reply1:

D D D D D D D D

(D =MS Byte of UID/Serial number from card)

Reply2:

D D D D D D D D

Reply3:

D D D D D D D D

Reply4:

D D D D D D D D

(D =LS Byte of UID/Serial number from card)

Note that the CARD UID command works independently of the PASSWORD mode.

The PASSWORD authentication only occurs for READ/WRITE operations.