Table of Contents
Advertisement
Optical Modulation Analyzer
Maintenance
Troubleshooting
The OMA can fail to display results if not configured correctly. Warning and error messages are shown in
red at bottom of the LabMaster touch screen display. While these messages are self-explanatory, two
common errors are discussed below to assist you with troubleshooting.
"OMA module not found!"
Check that the coherent receiver hardware unit is turned on and the USB cable is connected between it
and the oscilloscope. The USB connection is mandatory for the device operation because the OMA
software requires stored calibration data.
"OMA cal unsuccessful"
OMA calibration can fail due to a number of reasons. If this occurs:
1) Check the optical data transmitter is on.
2) Check that the wavelength of the laser (internal or external) matches that of the transmitter.
3) Check RAW traces in OMA to make sure that signal values are not clipped or too low. Some
transmitters do not send stable signals right after they are powered on. Any RX calibration during
this phase will fail as the signal may clip when out of range.
Another common failure mode is that calibration succeeds, but output eye and constellation diagrams
are collapsed. This can happen for a number of reasons:
Laser wavelength for the transmitter and receiver do not match.
•
Laser (internal and external) power level is too low.
•
Transmitter signals are not at the right power.
•
Transmitter bias settings need adjusting. Please consult your transmitter's manual to find out
•
how to perform this operation.
Modulation type set on the Optical Inputs dialog is different from the actual signal input to the
•
system.
Symbol rate set on the Optical Inputs dialog is not correct.
•
54
Advertisement
Table of Contents
