Strange thing happened.
I installed an extra application server (we had none) for our system but know the batch processes and update processes on the database server run into hold and error.
According to the log file due to TNS no listener
Database error 12541 at CON
> ORA-12541: TNS:no listener
Initialization DB-Connect Failed, Return Code 000256
But listener is running normally and also DB is up and running and able to access sqlplus
HP-UX, Oracle 11.2.04, ECC EHP6 and kernel 7.21 EXT UC
All other processes are working fine