Keysight EXG and MXG X-Series Signal Generators User’s Guide 95Optimizing Performance for All ModelsUsing the Power Meter ServoUsing the Power Meter ServoThe Power Meter Servo mode uses power meter readings to adjust the output power of the source,maintaining a constant DUT output power.The servo loop measures the output power of the DUT, compares it to the user-provided referencepower, and adjusts the output of the source to achieve the user-provided power level within thesettling error. The servo loop will abort after twenty unsuccessful attempts to achieve theuser-provided power level.Figure 5-14 Power Meter Servo MenusFor details on each key, use key help asdescribed on see page 56.See page 87Sets the allowedsettling error.The system automatically adjustspower level according to the powermeter reading.Once performs the adjustment only atthe end of any transition (amplitude orfrequency change). After theadjustment is performed and thepower error is corrected, no furtheradjustments are performed until thenext transition.Continuous performs the adjustmentas in Once mode, and continues toadjust the power periodically if thevalue differs by more than thespecified Settling Error.N5173B/83B onlyN5173B/83BonlySets the relative initial powerwhen leveling with the PowerMeter Servo mode. Thedefault of 0 dB means that thesystem starts with the powerit thinks is needed (based onoutput power, offset andreference) but this might leadto power overshoots in certaincases (especially when theoffset is not set up correctly).This value allows to specifyan additional safe-margin tostart the measure/adjustcycles lower than the targetpower to protect the devicefrom power overshoots.
