I do not see Huawei as a supported NAS device. Please look at the following document:
NetWorker Hardware Compatibility Guide, starting on page 262
Also, As per NetWorker 8.2.x Administration Guide,
EMC Celerra, Isilon, VNX, and NetApp filers with NDMP version 4 or later support token-based backups (TBB) to perform NDMP full, incremental, and level 1-9 backups. NetWorker supports the same number of incremental levels that the NAS vendor supports. EMC Celerra, Isilon, and NetApp documentation provide the maximum number of incremental levels that the TBB incremental backup can support.
When you configure TBB after you update the NetWorker server from 7.6 SP1 or earlier, the first incremental or level 1 to 9 backups does not occur until after one complete full backup.
Filers that do not support TBB, do not support incremental backups. If you select the level incr, the NetWorker server performs a full backup. However, you can schedule level backups to function like incremental backups. For example, define a weekly backup schedule of full on day 1, level 1 on day 2, level 2 on day 3, level 3 on day 4, and so on.
Verify the NAS storage vendor supports NDMP incremental backups before you use this feature.
Using TBB is available and supported on your NAS, then you define this in the NetWorker client’s Application Information field: USE_TBB_IF_AVAILABLE=y