EXFO MAX-890 - Page 342

Test Functions
334 MAX-800 Series
FEAC
 Loopback Commands
 Current displays the valid message received in the last second of
measurement. A valid message is detected only when receiving 10
consecutive occurrences of a specific Loopback Command
immediately followed by 10 occurrences of a specific Channel
Codeword.
 Previous displays the last valid message received excluding the
actual Current message.