:MEASure:EYE:TDEQ:OMA:METHod

Command Syntax

:MEASure:EYE:TDEQ:OMA:METHod {MEASured | UDEFined}

Query Syntax

:MEASure:EYE:TDEQ:OMA:METHod?

Description

Sets the method that the TDEQ (Transmitter and Dispersion Eye Closure for PAM4) is determined during a TDECQ measurement (:MEAS:EYE:TDEQ command).

UDEFined

This is the recommended selection. With this selection, you first must perform an Oscilloscope mode OMA measurement (:MEASure:OSCilloscope:OMAmplitude command) and enter the resulting value. OMA is the difference between the optical power of an PAM4 level three pulse and the optical power of an PAM4 zero pulse. When you make the measurement, use a pattern that contains consecutive runs of ones and zeros as called out in many standards. This pattern allows the one and zero levels to settle out to minimize the effect of level transitions.

MEASured

This is the default setting. The OMA value is automatically derived during the TDEQ measurement using the OMA at Crossing measurement. Since a pattern of consecutive ones and zeros is not used during the OMA measurement (as is done when entering a user-defined OMA value), the resulting TDEQ measurement can be too optimistic.