# Ratio of Level Mismatch

For PAM3 and PAM4 signal types, the Ratio of Level Mismatch is a measure of the smallest separation between adjacent levels divided by the ideal separation.

When adding this measurement, the waveform on which measurements are made depends on the selected SNDR Standard:

Waveform on which measurements are made for PAM4 SNDR standards
Standard | Waveform on which measurements are made
--- | ---
PCIe | The selected Source input channel
IEEE (PRBS13Q) | The SNDR Input waveform
IEEE 802.3 dj | The SNDR Input waveform
ASA SG4, 5 | The SNDR Input waveform

Waveform on which measurements are made for PAM3 SNDR standards
Standard | Waveform on which measurements are made
--- | ---
USB4 Gen 4 | The SNDR Input waveform

## SCPI Command

`:MEASure:SNDRatio:RLMismatch`