Command Syntax

:SPRocess:FFT:PREFerence {LEFT | CENTer | MANual}

Query Syntax

:SPRocess:FFT:PREFerence?

Description

When the FFT output has been defined as phase, unwrapped phase, or group delay (FFT:DISPlay command), use this command to set the FFT phase reference to LEFT, CENTer, or MANual. When MANual is specified, use the FFT:PREFerence:TORigin command to set the FFT origin in seconds.