ACS ACR1255U-J1, Reference Manual

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ACR1255U-J1 – Reference Manual
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Page 48 of 73
6.4.6. Read Value Block
This command is used for retrieving the value from the value block. This command is only valid for
value block.
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. 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 FCh
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 90h 00h The operation is completed successfully.
Error 63h 00h The operation is failed.