N5161A/62A/81A/82A/83A MXG Signal Generators User's Guide

Basic Digital Operation (Option 651/652/654)Multiple Baseband Generator SynchronizationUnderstanding the Master/Slave SystemSystem DelayThe multiple BBG synchronization feature provides a system for synchronizing the waveformgeneration capability of up to 16 signal generators to within a characteristic value of ± 8 ns betweenthe master and the last slave. This minor amount of delay (± 8 ns) can be reduced further topicosecond resolution by using the I/Q Delay softkey located in the I/Q menu. To reduce the delay,check and adjust the BBG signal alignment for each signal generator in the system. For moreinformation on adjusting the delay, see “I/Q Adjustments” on page 201.The delay value includes compensation for cables that have less than 1 ns of propagation delaybetween the EVENT 1 and PAT TRIG connectors (see Equipment Setup). The recommended cable is anAgilent BNC cable, part number 10502A. The use of cables with greater propagation delay may notallow the signal generators to properly synchronize.System SynchronizationSynchronization occurs after the master signal generator sends a one–time event pulse thatpropagates through and to each slave in the system. Prior to this event, each slave must recognizethat it is waiting for this event pulse, which occurs during the system configuration (see “Configuringthe Setup” on page 222). In order to properly send the synchronization pulse, the trigger source andthe Dual ARB Player for each signal generator must be turned off.The master/slave setup does not incorporate a feedback system between the slaves and the signalgenerator selected as the master. After synchronization, if changes occur to the Multi–BBG SyncSetup menu or a signal generator is added to the system, the master does not automaticallyresynchronize the setup. This may cause the signal generators in the system to incorrectly reporttheir status as In Sync.The system can also misinterpret other signals as the synchronization pulse, which results in anincorrect In Sync status. These types of signals include a continuous trigger or an active Markerrouted to the EVENT 1 connector. Improperly connected rear panel cables can also create a falsestatus.You must resynchronize the entire system after making any change in one or all of the Multi–BBGSync Setup menus, after adding a signal generator to the system, or in doubt as to the true status ofa signal generator. Changes to parameters that are outside of the Multi–BBG Sync Setup menu suchas waveform files, Dual ARB state, sample rate, scaling, carrier frequency or amplitude have no effecton the system synchronization. To resynchronize a system, see “Making Changes to the MultipleSynchronization Setup and Resynchronizing the Master/Slave System” on page 224.System Trigger SetupThe multiple BBG synchronization feature restricts the trigger selections (see page 219) for eachsignal generator. For signal generators selected as slaves, you can only modify the trigger type (withrestrictions). The trigger source is fixed and set to receive a trigger through the rear panel PAT TRIGconnector. On the master, you can change both the trigger type (with restrictions) and the triggersource. The trigger source provides three options for triggering the waveforms: external trigger, frontpanel Trigger key, or the GPIB trigger.If the trigger settings are other than what the BBG synchronization feature supports, the featurechanges the trigger settings to what is shown on page 219. When this change occurs, the Agilent MXGgenerates a settings conflict error to alert you to the changes. To avoid the error generation,Agilent N5161A/62A/81A/82A/83A MXG Signal Generators User’s Guide 221