Agilent Technologies N1911A Programming Manual page 124

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.
96 N1911A/1912A P-Series Power Meters Programming Guide