1. Export the following variables :
export OB2APPNAME=<SID>
export OB2BARLIST=<Original Backup barlist>
2. Now run the ob2rman.pl command as in the following example where the original hostname of the original backup is specified :
/opt/omni/lbin/ob2rman.pl -restore_controlfile -session 2016/01/29-1 -apphost systema.usa.hp.com
[Normal] From: ob2rman@systema.usa.hp.com "QDB" Time: 02/23/16 04:00:09
Starting restore of target database.
Net service name: QDB.
Instance status: OPEN
Instance name: QDB.
Database DBID = 3400754956.
Database control file type: CURRENT.
Database log mode: ARCHIVELOG.
[Normal] From: ob2rman@systema.usa.hp.com "QDB" Time: 02/23/16 04:00:10
Starting restore of Data Protector managed control file backup.
[Normal] From: ob2rman@systema.usa.hp.com "QDB" Time: 02/23/16 04:00:56
Restore of Data Protector managed control file backup completed.
Location: /var/opt/omni/tmp/ctrl_QDB_16514.dbf.
[Normal] From: ob2rman@systema.usa.hp.com "QDB" Time: 02/23/16 04:00:56
Restore of target database completed.