Command
:CALCulate<Ch>[:SELected]:LIMit:OFFSet:MARKer
This command sets the current active marker value as the limit line amplitude offset value.
Ana.WriteString ":CALC1:LIM:OFFS:MARK", True
Analysis > Limit Test > Limit Line Offsets > Marker -> Amplitude Offset
SCPI.CALCULATE(Ch).SELECTED.LIMIT.OFFSET.MARKER