Cannot add additional HDB nodes to smsy

Dear Hana experts:

We have a HDB with 2 nodes and each has its own server FQDN: CHARLOTT1 and CHARLOTT2.

We can add CHARLOTT1 as DB server to our solution manager's SMSY, but anyway we cannot add the other one.

Seems it is because both have the same SID.

We notice following blog but no hint is found:

http://www.happyhana.nl/viewtopic.php?t=41&p=69

Could you kindly direct me to some links or blogs about this topic?

Thanks!