ACR89U-A2 – Reference Manual
Version 1.01
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Page 48 of 57
4.1.2.3.6. Read Value Block
The Read Value Block command is used for retrieving the value from the value block. This command
is only valid for value blocks.
Read Value Block APDU Format (5 bytes)
Command
Class
INS
P1
P2
Le
Read Value Block
FFh
B1h
00h
Block Number
04h
Where:
Block Number
1 byte. The value block to be accessed.
Read Value Block Response Format (4 + 2 bytes)
Response
Data Out
Result
Value
{MSB .. LSB}
SW1
SW2
Where:
Value
4 bytes. This is the value returned from the card. The value is a signed long
integer (4 bytes).
Example 1
: Decimal - 4 = {FFh, FFh, FFh, FCh}
Value
MSB
LSB
FFh
FFh FFh
FC
Example 2
: Decimal 1 = {00h, 00h, 00h, 01h}
Value
MSB
LSB
00h
00h
00h
01h
Read Value Block Response Codes
Results
SW1 SW2
Meaning
Success
90 00h
The operation is completed successfully.
Error
63 00h
The operation has failed.