Siemens TC63 - Manual (Page 430)

TC63 AT Command Set
18.15 AT^SNFS
s
TC63_ATC_V00.490 Page 430 of 501 5/24/05
Confidential / Draft - Do not copy
To switch back and forth:
AT^SNFW
Stores the audio mode and the interface.
OK
AT^SNFS=4
Switches to the handset connected to analog interface 1.
OK
AT^SNFS=2
Switches to the handsfree device at analog interface 2.
OK