Trigger Source DescriptionBus Selects GPIB device trigger, *TRG, or (Group Execute Trigger).External Selects ANY pin that has been configured as a Trigger Input on the digital con-trol port.Immediate Triggers the transient as soon as it is INITiated.Pin<1-7> Selects a specific pin that is configured as a Trigger Input on the digitalcontrol port.Use the following commands to select one of the available trigger sources:Front Panel Menu Reference SCPI CommandNot available To select Bus triggers:TRIG:ELOG:SOUR BUSTo select digital pin 5 as the trigger:TRIG:ELOG:SOUR PIN5Initiate and Trigger the ElogWhen the power supply is turned on, the trigger system is in the Idle state. In this state, the triggersystem is disabled, ignoring all triggers. The INITiate command enables the measurement system toreceive triggers. To initiate and trigger the Elog:Front Panel Menu Reference SCPI CommandNot available To initiate the Elog:INIT:ELOGTo trigger the Elog:TRIG:ELOGAlternatively, if the trigger source is BUS, you can also program a *TRGor an IEEE-488 command.When triggered, the Elog starts placing data in the internal measurement buffer. Because the buffer isonly large enough to hold 20 seconds of accumulated measurement your PC application mustperiodically retrieve (or fetch) the data from this buffer.Periodically Retrieve the DataEach FETCh command returns number of requested records of the data in the buffer and removesthem, making room available for more data. The Elog continues until it is aborted.An Elog record is one set of voltage and current readings for one time interval. The exact format of arecord depends on which functions have been enabled for Elog sensing. If all functions are enabled,then one record will contain the following data in the specified order:Current averageKeysight RP7900 Series Operating and Service Guide 1434 Using the Regenerative Power System
