EXFO FTB-800 Series for FTB-1 - Manual (Page 363)

Test Results
NetBlazer 353
Summary (ISDN PRI)
The top left corner of each button indicates the channel number on a
background color as follows. The color coding remains when the test is
stopped or when the call ends.
The channel buttons also used background colors as follows:
Channel Number
Background Color
Description
Yellow At least one alarm/error occurred during a data call.
Red An alarm/error occurred in the last second of a data
call.
Green No alarm/error has occurred during a data call.
Button Description
Red An alarm/error occurred in the last second of a data call.
The Status Bit Error or Pattern is displayed.
Green No alarm/error has occurred in the last second of a data
call. The status No Alarm is displayed.
Blue Either a Speech or 3.1 kHz call is established, any call type
is terminated, or the test is stopped.
(Greyed Out)
Disabled
When a channel button is disabled, it implies that no call
was established on the channel after the test started.