EXFO FTB-800 Series for FTB-1 - Manual (Page 99)

Test Setup - Test Configurator, Timer, and System
NetBlazer 89
Modify Structure Button

Topology allows the selection of the network test topology.

Coupled uses the same settings for both the TX and RX signals.

Decoupled uses independent settings for TX and RX signals.
However, the pattern and some other parameters are always
coupled. Decoupled is not supported with OTN BERT test
application.

Through loops the RX signal to the TX port without TX overwrite
capabilities.

Dual RX uses two DS1 or DS3 signals at the same time. Both RX
ports are coupled at the exception of the termination mode. Only
available with DS1 and DS3 signal rates.