Backup job not getting completed

Hi,

I have a BE12.5 server in a branch office. When the weekly job runs, it doesnt get completed and the tape ejects automatically. So when i see the status of the job, it says the following:-

Completed status: Canceled, timed out
The job was automatically canceled because it 
exceeded the job's maximum configured 
run time.

How do i configure the job so that it completes the write operation to tape.

Thanks,