in reply to: Command 13 Read Tag, Descriptor, Date posted by Jens on 31 August 2011 at 07:45:00.
I found a hint to the uninizialized Strings. Command Summary Specification says in 5.1.1 that uninitialized Packed ASCII strings must be set to the question mark (?) character. Four question mark characters appear as the bytes 0xFF, 0xFF and 0xFF.