Keysight InfiniiVision M9241A, Startup Manual

Page: 39 / 72

Make a Measurement
7
Keysight M9241/42/43A PXIe Oscilloscopes and M9240A AutoProbe Power Module Startup Guide 39
2
If you want to return to the oscilloscope settings that existed before , click Undo
Autoscale .
3
If you want to enable "fast debug" autoscaling, change the channels
autoscaled, or preserve the acquisition mode during autoscale, click Fast Debug ,
Channels , or Acq Mode .
These are the same softkeys that appear under Main Menu > Utilities > User
Options Menu > Preferences > Autoscale .
If you see the waveform, but the square wave is not shaped correctly as shown
above, perform the procedure "Compensate Passive Probes" on page 39.
If you do not see the waveform, make sure the probe is connected securely to the
front panel channel input BNC and to the left side Probe Comp terminal.
How Autoscale
Works
Autoscale analyzes any waveforms present at each channel and at the external
trigger input.
Autoscale finds, turns on, and scales any channel with a repetitive waveform that
has a frequency of at least 25 Hz, a duty cycle greater than 0.5%, and an
amplitude of at least 10 mV peak-to-peak. Any channels where no signal is found
are turned off.
The trigger source is selected by looking for the first valid waveform starting with
external trigger, then continuing with the lowest number analog channel up to the
highest number analog channel.
During Autoscale, the delay is set to 0.0 seconds, the horizontal time/div (sweep
speed) setting is a function of the input signal (about 2 periods of the triggered
signal on the screen), and the triggering mode is set to Edge.
Compensate Passive Probes
Each oscilloscope passive probe must be compensated to match the input
characteristics of the oscilloscope channel to which it is connected. A poorly
compensated probe can introduce significant measurement errors.
1
Input the Probe Comp signal (see "Input a Signal" on page 36).
2
Choose Main Menu > Default Setup to recall the default oscilloscope setup (see
"Recall the Default Oscilloscope Setup" on page 37).
3
Choose Main Menu > Autoscale to automatically configure the oscilloscope for
the Probe Comp signal (see "Use Autoscale" on page 38).
4
Click the channel button to which the probe is connected (color-coded 1 , 2 , etc.
at the top of the SFP window).
5
In the Channel Menu, click Probe .
6
In the Channel Probe Menu, click Probe Check ; then, follow the instructions
on-screen.