Keysight E4428C ESG RF Programming Manual page 198

Programming the Status Register System
Status Groups
This is the named
status register for
the E4438C.
However, not all
signal generator
models use all of
the shown events
(i.e. some use only
a subset of the
E4438C's status
registers).
Data Questionable Condition Register
The Data Questionable Condition Register continuously monitors the hardware and firmware status of
the signal generator. Condition registers are read only.
190 Keysight Signal Generators Programming Guide