EXFO FTB-8500 Series for FTB-200 - Manual (Page 74)

Introducing the Smart User Interface
60 FTB-8500 Series and FTB-8120NGE/8130NGE
Keyboard Usage

Full keyboard: Allows entering numbers, letters and some other
characters. The Back, Del, Shift and space bar keys have the same
functionality as a regular PC keyboard.

Trace message keyboard (WAN): Allows entering alphanumerical
characters (ITU T.50) required for J0 and J1 Trace fields. the Ctrl
button to access these characters.