EXFO FTB-800 Series for FTB-1 - Manual (Page 269)

Test Results
NetBlazer 259
Alarms/Errors

Undersize
RX: Frames smaller than 64 bytes with a valid FCS.

Oversize Monitoring check box, when selected (cleared by default),
allows monitoring the Oversize frame errors.
The following errors are only available with Half Duplex mode (only for
electrical interface at speeds of 10 Mbit/s and 100 Mbit/s).

Collision
RX: Indicates the number of collisions on the link.

Late Coll.
RX: Indicates the number of collisions that have occurred after a 64
bytes transmission.

Exc. Coll.
RX: Indicates the number of frames that were sent 16 times
unsuccessfully due to consecutive collisions.