No errors being thrown in the Oracle Backup Sequence after initiating RMAN connection to channels.
Upon review it would seem that the Oracle Plugin is configured correctly with paths and set names input correctly
No password file stored in Oracle.
Normally, as a DBA you would use sqlplu "/as sysdba" to connect to the database. No need to enter a password. However, this is due to using OS Level Authentication. By default, the Oracle Plugin will use OS Authentication unless you use a password file.
So, when configuring the NetVault Oracle Plugin, be sure to de-select ' Use Oracle Password File Authentication'
See below more details on both authentication types from the "NetVault Plugin for Oracle" User's Guide.