Abstract: Multiple signals are graphically presented. A signal for each measured frequency channel is separately represented on a display. Representations of the signals are superimposed. Center channel frequencies for all the representations of the signals are aligned relative to a single position on a first axis. Amplitude for all the representations of the signals is indicated relative to a second axis. Overlap of a signal within a compliance mask indicates violation of an amplitude minimum, an amplitude maximum or frequency drift.

Abstract: A display method depicts rendered waveforms and markers in a manner that enables a user of an instrument or system to view a marker and a rendered waveform on a display, even in regions of the display where the marker and the rendered waveform overlap. The display method defines the marker by a series of contours on the display, grades the contours in the series at positions on the display where the rendered waveform does not coincide with the contours, and interleaves display elements of the display within the contours at positions where the rendered waveform coincides with the contours. The display method is alternatively implemented in a system, which includes a driver and a display, that depicts the rendered waveform and the marker.

Abstract: Multiple signals are graphically presented. A signal for each measured frequency channel is separately represented on a display. Representations of the signals are superimposed. Center channel frequencies for all the representations of the signals are aligned relative to a single position on a first axis. Amplitude for all the representations of the signals is indicated relative to a second axis. Overlap of a signal within a compliance mask indicates violation of an amplitude minimum, an amplitude maximum or frequency drift.

Abstract: A method automatically scales a sampled representation of a waveform applied to a sampling system, regardless of the nature of the waveform. The method, implemented within a digital oscilloscope or other type of sampling system, achieves amplitude auto-scaling from samples of the applied waveform acquired when the sampling system is un-triggered. The method then determines the nature of the applied waveform based on the number of acquired samples within an intermediate amplitude band and the number of amplitude transitions across the amplitude band. Records are then taken with the sampling system triggered and the occurrence of alternative designated events, based on the nature of the waveform, is detected within the records. Time offset and time gain are adjusted based on a first occurrence and a second occurrence of the designated event.

Abstract: A scale control method provides fine scale control in a measurement instrument and also provides scale control spanning wide adjustment ranges. The method detects the presence of the user input to a control sensor and establishes an acceleration factor for the input based on a rate at which events are generated by the control sensor. The acceleration factor modifies a defined scale step size that has a correspondence to the events generated by the control sensor. The defined scale step size, as modified by the acceleration factor, is added to a prior scale to establish a present scale. The present scale and prior scale are used to select a detent value from a series of detent values and to determine if a detent is applicable. When a detent is applicable, the present scale is set to the selected detent value and control of the scale parameters is then determined by this detent value.

Abstract: A phase-lock loop for a swept synthesized source in which hysteresis, tuning nonlinearity, and drift over time and temperature of an oscillator incorporated into the swept synthesized source are compensated. The tuning current to the oscillator is initialized to zero to eliminate hysteresis effects. Then, the pretune current is set to produce the minimum operating frequency of the oscillator. Next, the main phase-lock loop is closed, and a low-frequency synthesizer is swept to in turn sweep the oscillator over a selected frequency span. If the selected frequency span extends over other frequency bands, the oscillator is swept to the maximum frequency of the present band and held at this frequency by a track and hold circuit. The main phase-lock loop is opened, the low-frequency synthesizer is re-initialized, the main phase-lock loop is again closed, and the low-frequency synthesizer is swept again. Each frequency band is crossed in a similar manner until the selected frequency span is swept.