![Advanced Card ACR89U-A2 Reference Manual Download Page 47](http://html1.mh-extra.com/html/advanced-card/acr89u-a2/acr89u-a2_reference-manual_2855854047.webp)
ACR89U-A2 – Reference Manual
Version 1.01
www.acs.com.hk
Page 47 of 57
4.1.2.3.5. Value Block Operation (Increment, Decrement, Store)
The Value Block Operation command is used for manipulating value-based transactions (e.g.,
increment a value of the value block, etc.).
Value Block Operation APDU Format (10 Bytes)
Command
Class
INS
P1
P2
Lc
Data In
Value Block
Operation
FFh
D7h
00h
Block
Number
05h
VB_OP
VB_Value
(4 Bytes)
{MSB .. LSB}
Where:
Block Number
1 Byte. The value block to be manipulated.
VB_OP
1 Byte.
00h = Store the VB_Value into the block. The block will then be
converted to a value block.
01h = Increment the value of the value block by the VB_Value. This
command is only valid for value block.
02h = Decrement the value of the value block by the VB_Value. This
command is only valid for value block.
VB_Value
4 Bytes. The value of this data, which is a signed long integer (4 bytes),
is used for value manipulation.
Example 1
: Decimal - 4 = {FFh, FFh, FFh, FCh}
VB_Value
MSB
LSB
FFh
FFh
FF
FCh
Example 2
: Decimal 1 = {00h, 00h, 00h, 01h}
VB_Value
MSB
LSB
00h
00h
00h
01h
Value Block Operation Response Format (2 Bytes)
Response
Data Out
Result
SW1
SW2
Value Block Operation Response Codes
Results
SW1 SW2
Meaning
Success
90 00h
The operation is completed successfully.
Error
63 00h
The operation has failed.