In BioStar 1 you had the option of reading the iClass card CSN or Secure ID. 

[BioStar 1 iClass card read option] - CSN or Secure ID

However in BioStar 2 you only have the option to read the secure ID with iClass cards. 

[BioStar 2 iClass card read option] - only format configuration 

In BioStar 2 only the secure ID read has been implemented to follow the industry norm.