Hewlett-packard Company

Mark S Allen

Steven C Bird

Stephen K Will

Phillip E Deaver

A drop out trigger captures waveform data when a normally continuous input signal is disrupted or interrupted. In the preferred embodiment, a conventional trigger detects a parameter periodically satisfied by the continuous signal and resets a timer whenever a trigger event occurs. The alarm count of the timer is set for an interval slightly larger than the periodic interval. If the timer reaches the alarm count, a measurement signal is generated.

Triggering for waveform recording

Both positive and negative time interval measurements between start and stop channel signals are made without ambiguity during repetitive measurements. Circuitry monitors the start and stop channel signals and automatically changes the arming of the measurement circuitry whenever drifting of the signals requires a change in arming. Once the start or stop channel event is chosen as the initial source of the arming signal, subsequent arming signal selections are accomplished automatically.

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Saratoga, CA, United States of America

Mark S Allen