Report the size of the encapsulated BLOB (uint8 *). 
- Parameters
 - 
  
    | self | The DOFValue. This must represent a single value of type BLOB (uint8 *), and must not be NULL. | 
  
   
- Returns
 - The size of the BLOB (uint8 *) held in the DOFValue.
 
- Exceptions
 - 
  
    | 0 | is returned if an invalid parameter is detected.  |