Keysight N1911A Programming Manual page 118

2 MEASurement Commands
The expected power level is set to +20 dBm.
The resolution is set to 3.
The source list on the N1911A is set to Channel A on both windows and their
measurements.
The source list on the N1912A is set to Channel A for the upper measurement on
both windows and Channel B for the lower measurement on both windows.
118 N1911A/1912A P-Series Power Meters Programming Guide