Agilent Technologies N1911A Programming Manual page 378

9 PSTatistic Subsystem
Error Messages
• If command is executed in other window besides expanded CCDF
• If command is executed when the specific trace is not visible , error
350
window, error –221 "Settings conflict: Requires CCDF expanded
window" occurs.
–221 "Settings conflict:Trace Not Present" occurs. Use the command
PST:CCDF:TRAC? to check if the trace is enabled.
N1911A/1912A P-Series Power Meters Programming Guide