User's Manual

ACG HF Multi ISO RFID Reader V1.0
ACG Identification Technologies GmbH 100
12.4.4.5 Read value block
Reads a value block. The command checks if data is in value block format. The read
value block command needs a successful login.
Command
Command Data
'rv' Value block (1 byte)
Answer
Answer Description
Data Read value (4 bytes)
'F' Error: General failure
'I' Error: value block failure
'N' Error: No tag in field
'O' Error: Operation mode failure
Example
Command Description
rv04 Reads value of block 4.
12.4.4.5.1 No value block 'I'
The value read back after the write value command is not a value block. Data was
written corruptly.
12.4.4.5.2 No tag error 'N'
This means that the tag does not respond, because either there is no tag present or
none of the tags in the field are authenticated ('l' instruction).
12.4.4.5.3 General failure 'F'
In addition to the case of a data read failure caused by bad transmission conditions,
this error is returned if a sector is addressed which is not located in the authenticated
area.
12.4.4.5.4 Operation mode failure 'O'
The tag is not ISO14443 type A compliant.