EXFO FTB-8500 Series for FTB-500 - Manual (Page 146)

Port Tabs
132 FTB-8500 Series and FTB-8120NGE/8130NGE
Electrical TX
Electrical TX
Press TEST, Port, and Electrical TX.
Configuration
Ethernet port crossover: Allows selecting the type of cable used.

When disabled, the cable used should be straight through.

When enabled, the cable used should be crossover.