Autoscale - HP 1660CS-Series User Manual

Oscilloscope Common Menus

Autoscale

Autoscale
Autoscale is an algorithm that automatically optimizes the display of one or
more waveforms. When you select the Autoscale field and choose Continue,
the autoscale algorithm starts.
What the Autoscale algorithm does when a signal is found
The autoscale algorithm first checks all input channels to determine whether
or not there are any signals present. The vertical scaling is then set as
required for each channel. Next the time base is scaled for a single input
channel, the trigger channel is selected, the data is acquired, and the
waveforms are displayed.
Finding the vertical settings The autoscale algorithm sets the
vertical scaling (V/Div and offset) appropriate to the input signal for
channel 1. This process is repeated for channel 2.
Finding the time base settings The time base settings (s/Div and
delay) are determined based on the input signal of Channel 1 (if active)
or Channel 2. The time base is scaled so that between two and five
complete cycles of the time base scaling source input signal can be seen
on the screen. The trigger settings are also changed by the autoscale
algorithm and an edge mode trigger with CHAN 1 or CHAN 2 is selected.
The channel selected for time base scaling is selected as the trigger
source.
Displaying the waveform When the autoscale algorithm is complete,
the oscilloscope automatically starts running, acquires the data, and
displays waveforms for the inputs that have been selected.
The trigger point on the waveform is determined by the trigger level set by
the autoscale algorithm. The trigger point is displayed as a dotted vertical
line at the center of the screen (Delay = 0 s).
What the Autoscale algorithm does when a signal is not found
If no signal is found, the autoscale algorithm toggles the Auto-Trig field to
On, which places the oscilloscope in the automatic trigger mode. The
oscilloscope then displays the message "Auto triggered." The automatic
trigger mode allows the oscilloscope to sweep automatically and to display a
baseline anytime a trigger signal is not present. All other settings are
restored to their original values.
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