EXFO FTB-800 Series for FTB-1 - Manual (Page 478)

Test Control
468 FTB-700G/800 Series
Headset/DTMF Button
Headset
Note: The settings here and on the platform are independent but platform
settings may limit level control. For more information, refer to Adjusting
Microphone and Speaker Volume from the platform user guide.

Speaker Volume: The slide bar and +/- buttons are used to increase or
decrease the volume of the speaker.

MIC Volume: The slide bar and +/- buttons are used to increase or
decrease the volume of the microphone.
DTMF
The DTMF phone-style button grid is used to enter the standard DTMF tone
(0-9,*,#). Alternatively the hard keyboard of the FTB-1 platform can be
used.