rman backup not writing to log file

We are using database version 11.2.0.3. I setup cron job to run rman backup. Looks like the cron job is running; however, there is no log generated. Is there any syntax error in the script I need to change? Gurus, please advise. Thank you very much.

Below is my script:

run_backup_full.sh

connect catalog username/password@RCAT
connect target username/password
RUN {

BACKUP
   FULL
   TAG Daily_Full_Backup
   DATABASE FILESPERSET=1
   ;
BACKUP
   CURRENT CONTROLFILE
   ;
SQL 'alter system archive log current';
BACKUP
   ARCHIVELOG ALL FORMAT '/ebs/dxibackup/archctl/%d_%t_%s_%p.arch';

DELETE NOPROMPT OBSOLETE;
CROSSCHECK BACKUP;
CROSSCHECK ARCHIVELOG ALL;