EXFO FTB-800 Series for FTB-1 - Manual (Page 580)

Glossary
570 FTB-700G/800 Series
SONET/SDH
Examples for AU-4 (3 level convention)
TU-3: [K,0,0]
TU-2: [K,L,0]
TU-12:[K,L,M] where M = 1 to 3
TU-11:[K,L,M] where M = 1 to 4
Example for AU-3 (2 level convention)
TU-2: [L,0]
TU-12: [L,M] M is numbered 1 to 3
TU-11: [L,M] M is numbered 1 to 4
The GUI Grid indicates the TUG-2 [x] and TUG-3 [x] values.