Furuno FS-2570 - Page 190

6.4 Tone test
6-14
(2) 4 to 6 Tone test
These tests are used to generate mark and space tones. The generated tone is observed at
TP4 on NBDP DSP board.
1) Tone test 1 (Mark)
Mark tone (1700 Hz-85 Hz) is generated.
2) Tone test 1 (Space)
Space tone (1700 Hz+85 Hz) is generated.
3) Tone test 1 (BY)
Mark and space tones (1700 Hz+85 Hz), 100 bps are generated.
The same tone is also generated through the system setting menu. See page 7-10.
Fig.6.4.2 DSP Board
TP4
TONE measurement