80 Keysight NFA Series Noise Figure Analyzers Service Guide
Instrument Messages
Event Messages
Event Messages
Event messages are displayed in the MSG area in the bottom left of the 
instrument display. Event messages and message numbers are defined by the 
SCPI standard.
In the X-Series, sub-messages are often attached to add additional 
information, to help you better understand the event being reported. For 
example, error –221 is defined as Settings Conflict, but in the X-Series 
you will often see a longer message appended to error –221, such as 
Settings Conflict; Function not available in Zero Span. This 
helps you understand the exact cause of the Settings Conflict error.