1. Tested the output wavelength of the SSN1SF64A/SF64A board with an optical spectrometer. The measurement value was approximately 1560 nm, instead of the required 1550.12 nm.
2. Tests showed that the default wavelength of a line board could be changed even when the board software remained unchanged. The following conclusions were reached:
a. Set a correct wavelength for the SSN1SF64A/SF64A board through the debugging interface and found that the SSN1SF64A/SF64A board output a correct wavelength. The output wavelength of the board remained correct even after the board was reseated or a cold/warm reset was performed on the board.
b. Re-set an incorrect wavelength for the SSN1SF64A/SF64A board that had already output a correct wavelength, and found that the SSN1SF64A/SF64A board always output an incorrect wavelength even after the board was reseated or coldly reset.
c. Found that the SSN1SF64A/SF64A board output a correct wavelength if a warm reset was performed on the board.
Based on the preceding conclusions, it is suspected that I2C communication is not reliable during the power-on or cold-resetting process of a line board, resulting in the output of an incorrect wavelength due to an initialization failure. If a correct wavelength is set for a line board, the line board outputs a correct wavelength even when re-initialization due to power-off fails, because the optical module of the line board can remember a preset wavelength.After a line board starts up, initializing an output wavelength is successful after a warm reset is performed on the line board, because I2C communication is normal in this case.