Wireless Access

Aruba 3400 and AP93 can diable ARM and manual Set Specific Channel ? If can, please advise the step

Yes, you can disable ARM and manually assign channels, but this is not advised in most environments.

In your AP group, navigate to RF Management, select the radio (A / G) and then under ARM, create a new profile and change assignment to "disable".

Then you can go into the main radio profile (802.11a or 802.11g) and assign the channel. (I would create a new profile with the channel settings).

Thanks.

you means diable ARM assignment? and in the regulatory domain profile, choose the channel value which I expert?

You can do it by creating different ARM profiles (like cappalli suggested) or Regulatory Domains (Defining what channels you want available for use) for each AP-Group 

May i know  the different with regulatory domain valid channel and ARM profile (802.11g profile) channel ? which channel setting will be apply to APs?

But in the 802.1g profile, channel only can assign one channel, about the above and below, I tested 3 APs, I set channel 6- . 3 APs' show 3 channel 6, 6, 9..