VOLTCRAFT 632 FG, Руководство пользователя

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5-2 Dual-channel Operation
Set the VERT MODE switch to DUAL to display trace in CH2 (The procedure
is same as CH1 described in previous section). At this step, the calibrator
signal appears in CH1 is Square wave, but it appears in CH2 is a straight line
as no signal applied to this channel yet.
Now, apply the calibrator signal to the vertical input terminal of CH2 through
the probe with the same procedure as for CH1. Set the AC-GND-DC switch to
AC, and adjust vertical POSITION knobs (11) and (19), the signals will be
displayed on both channels as shown in Figure 5-2.
Fig. 5-2
When ALT/CHOP switch is released (ALT MODE), the input signals which applied respectively to CH1and CH2 appears
on the screen alternately at each sweep. This setting is used when the sweep time is short in 2-channel observation.
When ALT/CHOP switch is pressed (CHOP MODE), the input signals which applied to CH1and CH2 are chopped and
display on the screen at the same time with the frequency of 250kHz. This setting is used for low speed sweep.
Set to dual channel operation (DUAL or ADD mode), select CH1 or CH2 signal from SOURCE switch to get triggering
source signal. If both CH1 and CH2 signals are in a synchronized relation, both waveforms will be displayed in stationary
states. If not, only a signal stationary waveform will be appeared. If press TRIG. ALT push button, both waveforms can
also be displayed in stationary states.
5-3 ADD Operation
An algebraic sum of the CH1 and CH2 signals can be displayed on the screen by setting the VERT MODE switch to
ADD. The displayed signal will be difference between CH1 and CH2 if press CH2 INV push button. Adjust
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POSITION knob of CH1 or CH2 can make vertical position, to the advantage of the linearity of the vertical amplifiers,
it’s better to set
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POSITION knob of both channels in middle position.
5-4 Triggering
Proper triggering is essential for an efficient operation of the instrument. Users must make themselves familiar with the
triggering functions and procedures thoroughly:
(1)Functions of MODE switch:
AUTO Select automatic sweep operation by setting to AUTO mode, the sweep generator will freely generate a
sweep without a trigger signal. However, it will automatically switch to triggering sweep operation if an
acceptable trigger source signal is preset. The AUTO mode is handy for observing the waveform when
first set up the instrument, as it provides sweep function for waveform observation until properly set to
other mode. Once starting to set the control mode, the operation often jumps back to the NORM trigger
mode as it is much more sensitive. Automatic sweep must be used for DC measurements and signals
with low amplitude in order not to trigger the sweep.
NORM
The NORM mode provides normal triggering sweep operation. The sweep will not act until the selected
trigger source signal crosses the threshold level set by TRIG LEVEL control knob. The triggering
generate one sweep which will come to inactivate until another triggering occurs. In the NORM mode,
there will be no trace unless an adequate trigger signal is present. In the ALT mode of dual trace
operation with NORM sweep selected, there will be no trace unless both CH1 and CH2 signals are
adequate for triggering.
TV-V Set the MODE switch to TV-V mode, select vertical sync pulses for sweep triggering to view composite
video waveforms. Select vertical sync pulses as a triggering to view vertical fields and frames of video.
A sweep time of 2 ms/div is appropriate for viewing fields of video and 5 ms/div for complete frames
(two interlaced fields) of video.