adding new tape drive to existing storage node for isilon ndmp backups

Hello i have two tape devices already configured to backup data on our emc Isilon filestorage via ndmp.  I am trying to add the two new tape devices to this pool. The drives are already installed in the library and zoned exactly like the currently working drives.  I do see the two new drives in networker but  they have the brown wrench beside them. 

Not sure of the process to get these two new drives working.