Setting Vertical Size And Offset - Tektronix 11801C User Manual

Vertical Controls
Setting Vertical Size
and Offset
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You can change the vertical magnification, or size, of a trace. You can also
move the trace up or down on the display. This is called adjusting the verti
cal offset. To do either, touch the vertical ( ) icon; this assigns the knobs to
adjust the vertical size (top knob) and offset (bottom knob) of a channel of
the selected trace.
If you want to change the size or offset of a different trace, touch the desired
trace to select it. Then use the knobs to adjust vertical size and offset.
Touch a knob label to display the keypad pop up menu. This lets
you set vertical size and offset numerically, or quickly set them to
maximum or minimum limits. It also lets you set the knob resolution.
Adjusting Channels and Adjusting Traces
When you adjust the vertical size or offset of a trace acquired in Fast mode,
you are adjusting the size or offset of one of the channels that is in the trace
expression. If the trace you are adjusting has the trace expression M1+M2,
you can adjust the vertical size of only one channel at a time. This has the
following side effects:
H Changing the channel size or offset for this trace changes the channel
size or offset for all the other traces that display that channel.
H If the trace you are adjusting has more than one channel in its trace
expression, changing the vertical size of one channel does not change
the size of the other channels. If the vertical scale factors of all the
channels in a trace do not match, the vertical size of the trace is unde
fined.
For example, in the case of the trace M1+M2, if M1 has a vertical size of
50 mV/div and M2 has a vertical size of 100 mV/div, the trace will have
undefined vertical units.
You can select which channel of the trace you want to adjust with the knobs.
Whenever the icon is highlighted, the lower right corner of the display
shows the Chan Sel selector. This selector always shows which channel the
knobs are set to adjust. You can touch this selector until it shows the chan
nel you want to adjust with the knobs.
Adjusting High Precision Traces
High precision traces use floating point arithmetic in their calculation. When
the selected trace is a high precision trace, you will see High Prec in the
bottom line of the Vertical Desc selector in the Waveform major menu.
You can adjust the vertical size and offset of high precision traces, without
adjusting a channel.
NOTE
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