Modul'n Amp (Signal Amp)
The Jitter mode modulation amplitude (Modul'n Amp) measurement is an optical measurement with the units in Watts. For any other units, the measurement is listed as Signal Amplitude (Signal Amp). Both measurements are the difference between the one level and zero level.
When making the measurement, be sure to check any relevant standard for one and zero run requirements in the pattern. When making the measurement on a square wave pattern, use Oscilloscope Mode's OMA measurement. Use this measurement to check for pattern dependencies and other issues by checking the results while using different patterns.
While the OMA measurement is made using the central 20% width of a consecutive run of ones and the central 20% width of a consecutive run of zeros, the modulation amplitude measurement is made from samples in a much narrower region. Also, depending on the settings in the Jitter Configuration dialog, the measurement may not be made in the center of the pattern runs. For example, you can change the Measurement Location setting from the default 50% (central) location. You can also define one and zero levels by minimum consecutive digits. Optical Modulation Amplitude (OMA) is the measure of the difference between the optical power of an NRZ one pulse and the optical power of an NRZ zero pulse. It requires an NRZ pattern and is designed to be used with square wave made of consecutive zeros following by consecutive ones. If needed, you can make an OMA measurement on any pulse train (not just a square wave) as long as enough consecutive symbols (ones or zeros) are included for the signal level to settle.
More Information
SCPI Command
:MEASure:AMPLitude:SAMPlitude