User's Manual

HF Mifare Easy Module V1.0
ACG Identification Technologies GmbH 33
7.4.3 Common commands
7.4.3.1 Increment value block (credit)
Increments a value block with a defined value. A read after write is done
automatically to verify data integrity. The command fails if the source block is not in
value block format. A previous log in is needed to access a block.
Command
Command Data
'+' Block (1 byte)
Value (4 bytes)
Answer
Answer Description
Data Value (4 bytes)
'I' Error: value block failure
'F' Error: increment failure
'N' Error: No tag in field
'X' Error: Unable to read after write
Example
Command Description
+0400000001 adds 1 to value block 4
+0500000100 adds 256 to value block 5
7.4.3.1.1 No value block 'I'
Specified block does not match the value format. The value block is corrupted. A
backup block can be used to restore the correct value.
7.4.3.1.2 Increment failure 'F'
General failure during increment procedure or unable to read after write.
7.4.3.1.3 No tag error 'N'
The reader does not detect a response of the tag. There is either no tag present or
the tag does not respond the request.