EXFO FTB-8500 Series for FTB-500 - Manual (Page 179)

Traffic Analyzer Tabs
Ethernet and Fibre Channel Application 165
Ethernet RX
The following errors are only available with Half Duplex mode. Not
available when Through Mode (FTB-8510B) is selected. Not available with
FTB-8510G.

Collision (10/100/1000Mbps): Indicates the number of collisions on
the link.

Late Collision (10/100/1000Mbps): Indicates the number of
collisions that have occurred after a 64 bytes transmission.

Excessive Collision (10/100/1000Mbps): Indicates the number of
frames that were sent 16 times unsuccessfully due to consecutive
collisions.
Total Error Count: Indicates the total number of errors including all the
above errors.