The UltraBlock SCSI bridge automatically searches SCSI addresses 0..6 and 8..15 for an attached SCSI device. The UltraBlock SCSI bridge itself uses the fixed SCSI ID 7, which is "standard" for host adapters. So, you only need to change a device's SCSI ID if it also happens to be set for SCSI ID 7, as that would conflict with the UltraBlock's own SCSI ID.