Keysight N1911A Programming Manual page 203

Query
CALCulate[1]|2|3|4:MATH[:EXPRession]?
The query returns the current math measurement setting on the specified window.
Query Example
CALC1:MATH?
Error Messages
– For the single channel N1911A power meter: if <string> is not set to "(SENS1)"
– For the dual channel N1912A power meter: if <string> is not set to "(SENS1)"
N1911A/1912A P-Series Power Meters Programming Guide
while SENSe:SPEed is set to 200, error –221, "Settings Conflict" occurs.
or "(SENS2)" while SENS1:SPEEd or SENS2:SPEEd is set to 200, error –221,
"Settings Conflict" occurs.
CALCulate Subsystem
This command queries the current setting
of the math expression on the upper
window/upper measurement.
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