Agilent Technologies N1996A-503 User Reference page 301

Bad Command
FREQ:STAR 30MHz;POW:MIX RANG
-20dBm
MIX and RANG require a colon to separate them.
:POW:ATT 40dB;TRIG:FREQ:STAR
2.3GHz
:FREQ:STAR is in the :SENSE subsystem, not the :TRIGGER subsystem.
:POW:ATT?:FREQ:STAR?
:POW and FREQ are within the same :SENSE subsystem, but they are two
separate commands, so they should be separated with a semicolon, not a
colon.
:POW:ATT -5dB;:FREQ:STAR
10MHz
Attenuation cannot be a negative value.
Chapter 5
Programming Fundamentals
SCPI Language Basics
Good Command
FREQ:STAR
30MHz;POW:MIX:RANG -20dBm
:POW:ATT 40dB;:FREQ:STAR
2.3GHz
:POW:ATT?;:FREQ:STAR?
:POW:ATT 5dB;:FREQ:STAR
10MHz
301