EXFO FTB-800 Series for FTB-1 - Manual (Page 470)

Test Functions
460 FTB-700G/800 Series
Spare Bits
Spare Bits
Note: Spare Bits are not available when the framing is set to Unframed.
From the Test menu, tap Functions, tap the Spare Bits tab.
TX
Tap a spare bits field to set its value.
Note: All spare bits are reserved for national use and should be set to 1 when not
used.

E4

G.751 Bit 14, 15, 16: Choices are 000 to 111 (default).

E3

G.751 Bit 12: Choices are 0 and 1 (default).

E1

S
i0
is located in the bit 1 of the frame containing the frame
alignment signal (FAS). Choices are 0 and 1 (default).

S
i1
is located in the bit 1 of the frame not containing the frame
alignment signal (FAS). Choices are 0 and 1 (default).

S
a4
to S
a8
are located in bit 4 to 8 of frame number 1, 3, 5, and 7 of
sub-multiframe 1 and 2. Choices are 0 and 1 (default) or 0000 to
1111 (default) depending on the selected framing.

TS16 Frame 0 Bit 5, 7, 8 are located in bit 5, 7, and 8 from Timeslot
16 of frame 0 of a E1 signal. Choices are 000 to 111 (default).