EXFO FTB-8100 Series Transport Blazer for FTB-500 - Manual (Page 291)

DSn Tabs
SONET/SDH Application 277
DS1/1.5M TX
Loopback
The Loopback feature generates a code that is interpreted by the DUT. The
DUT interprets the command and implements the loopback.
³
Type allows the selection of the type of loopback. Choices are
CSU (10000/100), NIU FAC1 (1100/1110), NIU FAC2 (11000/11100),
NIU FAC3 (100000/100), 10 predefined Loop Codes (refer to DSn Loop
Codes on page 543), and User Defined.
³
Loop-Up and Loop-Down: Indicates respectively the Loop-Up and
Loop-Down code corresponding to the selected loopback type. When
the selected loopback type is User Defined, enter the Loop-Up and
Loop-Down loopcode values from 3 to 16 bits (000 to
1111111111111111).
³
Command: Allows the selection of the loopback codes that will be
used to overwrite the traffic that will be generated. Choices are
Loop-Up and Loop-Down. The default setting is Loop-Up.
³
Send: Allows the injection of the selected loop code. The loop code
will be generated continuously for a maximum of 10 seconds or until
the loopback is confirmed. After 10 seconds, if the loopback has failed,
a Loop-Down command is sent. A pop-up window appears indicating
the loop code injection progress and result.
Loopback Type
Command
Loop-Up Loop-Down
CSU (10000/100) 10000 100
NIU FAC1 (1100/1110) 1100 1110
NIU FAC2 (11000/11100) 11000 11100
NIU FAC3 (100000/100) 100000 100