cli (config-if-wlan-0-X)#
Syntax
Call the command without parameter assignment:
no wlan dfs
Result 
The DFS function is enabled.
Further notes
You display the setting with the show wlan basic <wlan 0/X> command. 
You enable the function with the wlan dfs command.
See also
wlan dfs (Page 240)
7.1.5.37 wlan dfs prefer-configured-channel
Description   
If the configured channel of a WLAN interface was blocked due to radar detection and is free 
again after 30 minutes the access point changes automatically to the configured channel.
Before the access point starts the communication on the configured channel it searches 60 
seconds for primary users on the channel. During this time the access point does not send 
beacons. If signals are found on the channel, the access point changes channel and repeats 
the check. Only when no signals from primary users are detected after 60 seconds does the 
access point send on the channel.
If no fixed channel is defined for the access points, the device has no configured channel to 
which it can return.
Requirement
● DFS is enabled.
● The access point does not select the channel automatically.
● You are in the Interface Configuration mode of the WLAN interface.
The command prompt is as follows: 
cli (config-if-wlan-0-X)#
Syntax
Call the command without parameter assignment:
Network structures
7.1 WLAN
SCALANCE W770/W730 acc. to IEEE 802.11n Command Line Interface
Configuration Manual, 09/2017, C79000-G8976-C324-08 241