Rohde Schwarz Rohde & Schwarz HMO1002 2-channel oscilloscope, Digital Storage oscilloscope, 21-1002-RS00 데이터 시트

The acquisition modes are selected by pressing the AC-
QUIRE 

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 key. This opens a display menu which offers the 

following acquisition modes:

This acquisition mode is intended specifically for very
slow signals, with the untriggered signal „rolling“ across 
the screen from right to left (requires signals slower than 
200 kHz). The R&S®HMO1002 uses a ring buffer to store 
the signal values in roll mode. Simply put, the instrument 
writes the first division to the first storage space, the se-
cond division to the second storage space, etc. Once the 
storage is full, the instrument overwrites the first storage
space with the data of the most recent measurement va-
lue. This creates a „ring“ or cycle run, similar to a ticker.

The soft menu ARITHMETIC offers following menu items:

 ❙REFRESH: 

This mode allows the capture and display of current 
signals.

 ❙

ENVELOPE: 
In this mode, the display includes the normal capture of 
each signal and the maximum as well as the minimum 
values of each capture. Over time, this creates an 
envelope surrounding the signal.

 ❙

AVERAGE: 
In this mode, you can use the universal knob in the 
Cursor/Menu section of the control panel to set the 
number of signal periods for averaging, available in 
powers of 2 from 2 to 1024 (requires repetitive signals).

 ❙

SMOOTH: 
The function SMOOTH is used to calculate the mean 
value from several adjacent sampling points. The result is
a smooth waveform. This function is used for non-perio- 
dic signals.

 ❙FILTER: 

In this mode, you can activate a low pass filter with
adjustable cut off frequency to suppress unwanted high
frequency interferences. The cut off frequency can be set 
based on the sampling frequency. The minimum setting is 
1/100 of the sampling frequency and the maximum value 
is 1/4 of the sampling rate. You can select this setting with 
the universal knob.

This mode is used for very large time base settings to 
detect even short signal changes. You can also deactivate 
this function within the menu (OFF) or you can select the 
automatic switching mode (AUTO). 

The following conditions must be met to activate the PEAK 
DETECT mode:

 ❙Function HIGH RESOLUTION is deactivated
 ❙None of the serial or parallel buses are active

5  Horizontal System

In the HORIZONTAL system 
section, users can select time 
base settings for capturing, 
trigger time position, zoom 
functions, acquisition modes, 
marker functions and search 
functions. Knobs allow you to 
set time base and trigger time 
position. A menu enables you 
to select the desired acquisi-
tion mode. A separate key is 
available to activate the zoom. 
Use the arrow keys     

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and the SET/CLR key to select 
marker functions.

The acquisition mode can be selected with the RUN/
STOP key 

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 In Run mode signals are shown on the screen 

according to the selected trigger conditions, discarding 
previously captured signals with each new capture. If you 
wish to analyze a captured signal on the screen without 
overwriting it, capture must be stopped by pressing the 
RUN/STOP key. While in STOP mode, you may not capture 
new signals and the key is illuminated in red.

The TIME/DIV knob in the HORIZONTAL section of the 
control panel is used to change the time base. The current 
time base setting (e.g.”TB: 500 ns”) is displayed in the up-
per right above the graticule. To the right of the display you 
can see the trigger time position in relation to the default 
setting. The default setting shows the trigger time position 
in the center of the display, with 50% of the signal display 
before and 50% after this trigger position. The X-POSITION 
knob 

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allows continuous adjustment of the x position.

The maximum values allowed depend on the time base 
setting. 

Pushing the SET/CLR key resets the value to its reference 
position as long as the marker or search functions have not 
been applied. The arrow keys     

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 allow you to change 

the X position by a fixed amount of 5 divisions in the
respective direction. The MENU 

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 key opens a menu to 

determine the function for the arrow keys     

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 and the 

SET/CLR key. As described above, these keys allow you to 
set the X position. Alternatively, you can use them to mark 
events within the signal with the option to navigate bet-
ween up to 8 markers. In the submenu NUMERIC INPUT 
you can enter any horizontal position directly. This menu 
also allows you to activate and set search functions. You 
can also set the TIME REFERENCE (position for the trigger 
reference point, from -5 divisions to +5 divisions with 0 
being the center and default setting).

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D

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Fig. 5.1: Control panel of the 
horizontal system