Agilent 6800 Series Triggering
In ATE applications, triggers are often a conven- ient way of synchronizing test system events and increasing test throughput. These benefits also apply to the triggering subsystems in the 6800 series products since these products combine the capabilities of many test instruments. Each model is equipped with the ability to send and receive triggers, and to perform or initiate a multitude of synchronized functions upon receiving a trigger.
Triggers can be used to change the output, syn- chronize a change to a phase of a waveform cycle, and synchronize a measurement to an output change. The effectiveness of the triggering capability can be shown when measuring worst case inrush current of a switching power supply. Using the 6800 series triggering subsystem, the output can be triggered to turn on at a phase near the peak of the ac cycle for simulating a worst case ac line condition. Simultaneously, the ac source can be triggered to take current measurements to charac- terize the behavior of the power supply under test. In addition, triggering can be extended to external test equipment via the Trigger Out connection.
The 6800 series has two main triggering subsystems, one for generating transients and one for making measurements. These two subsystems have common trigger sources that can synchronize transient and measurement events.
What Actions Can be Triggered?
The following actions of the 6800 series can be triggered:
•a change in output setting
•the start of a Step, Pulse, or List transient
•the pace of a List sequence
•the acquisition of digitized voltage and current
•the synchronization of an output change to a phase of the cycle
A programmable time delay can be specified for triggers that generate output changes. This allows the insertion of a specified time delay between the receipt of the trigger and the action of the ac power source/analyzer output.
What Can Serve as the Source of the Trigger?
The 6800 series can receive triggers from the following sources:
The GPIB. The computer can send trigger commands to the ac power source/analyzer. There is a short command processing time associated with this source.
External Trigger In. This is the 6800 series TRIGGER IN connector. It accepts TTL levels, with the falling edge detected as the trigger.
TTL Trigger. The TTL trigger is an internal trigger that causes the acquisition of digitized voltage and current data.
This internal trigger can be generated when an output transient begins or ends, or as the result of List step execution.
How Can Triggers be Generated?
The 6800 series can generate a trigger on the TRIGGER OUT connector as a result of the follow- ing actions:
•the beginning of a Step, Pulse, or List output transient
•the completion of a Step or Pulse output transient
•the completion of a List sequence
•the beginning of a List step
The TRIGGER OUT signal is a nominal
How Can the Agilent 6800 Series be Enabled to Respond to a Trigger?
The default state of the ac power source/analyzer is the idle state where trigger detection is disabled. To respond to a trigger, it must be placed in the “initiated state.” This can be done via the front panel or over the bus. Once initiated, the ac power source/analyzer can detect a trigger from the selected source.
When the trigger is detected, the ac power source/ analyzer will perform the trigger action after wait- ing any programmed trigger delay time. Upon com- pletion of the trigger action, the ac power source/ analyzer will return to the idle state.
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