EXFO FTB-8500 Series for FTB-200 - Manual (Page 209)

Traffic Analyzer Tabs
Ethernet and Fibre Channel Application 195
FC TX
FC TX
Press Menu, Test, Traffic Analyzer, and FC TX.
Alarm Generation

Type: The following error is available: Link Down. Note that a Pattern
Loss alarm will be detected when injecting a Link Down while the
PSP (Link Protocol) check box is selected (Refer to PSP (Link
Protocol) on page 139).

On/Off button: The On/Off button is used to activate/deactivate the
selected automated error continuously. This setting is disabled (Off) by
default.