Display; Setting Of Parameters; Fig. 4.3: Front View Including Display Of The Settings; Fig. 4.4: Front View Including Display Of The - Hameg HMF2525 Handbuch

the knob CW resp. CCW. The parameter selected can the set
after pushing the knob. The value set will be accepted by pushing
the knob again.
Examples of setting parameters:
The following examples demonstrate the setting of parameters
for the square wave function. First push the square wave key
below the keyboard. You will see the following display:

Fig. 4.3: Front view including display of the settings

In this case the signal frequency was set to 50.0000000 kHz.
The simplest method of entering parameters quickly and ex-
actly is the entry via the numerical keyboard
parameters via the keyboard the value will be accepted upon
pushing the respective unit key MHz, kHz, Hz or mHz. If you
hold the ESC key ( button), the value input window vanishes
at any false entry via the keyboard. If an illegal value was en-
tered, the instrument will automatically jump to the minimum
or maximum value of the selected function.
In order to clarify this, enter a frequency of 20.56 kHz. Setting
the frequency is possible if the respective key of the softkey
menu lights up blue. Push the keys
proper sequence. The value entered will be accepted by pushing
the key to the side of the numerical keyboard. The following
display will be shown:
Fig. 4.4: Front view including display of the settings changed
Alternative methods of parameter entry are with the knob
Now push the second soft key (its blue LED will light up if it is
active) in order to set the amplitude. Use the left cursor key to
select the first decimal position of the numerical value. Use the
knob to set 2.000 V. The display will show:
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Fig. 4.5: Front view including display of the amplitude change
O p e r a t i o n o f t h e H M F 2 5 2 5 / H M F 2 5 5 0
. When entering
4
, , , and in
.
10
The entries of Sweep, Offset etc. are performed following the
same procedure. If the signal output of the function generator
is connected e.g. to an oscilloscope, the signal may be shown
on the display of the oscilloscope. The key
white LED is lighted.
4.5

Display

Depending on the type of function selected, the HMF2550 /
HMF2525 will display a preview of the waveform of the signal.
When the basic waveform is changed, the preview will be
adapted accordingly. This allows to see immediately how the
signal reacts to the entries. Above this display the setting of the
impedance (e.g. 50 Ω, HIGH Z or user defined), the selection of
the external or internal clock, and the selected interface will
be shown.
The right portion of the display shows the variable parameters
in the soft key menu. This menu will be adapted to the waveform
selected. The setting of the parameters will be explained in the
following section „Setting of parameters". Most of the soft keys
are dual function: the active function will be shown in blue and
the inactive one in white letters. Pushing the key will alternate
between functions.
The frequency display is a 9 digit one with a maximum resolu-
tion of 10 µHz. The peak-to-peak values of amplitude, high/low
level, and offset are displayed with a maximum of 5 digits and
a maximum resolution of 1 mV. The period is selectable in 1ns
steps starting from a minimum value of 20 ns.
Please note that the maximum output amplitude which
can be set will depend upon the (load) impedance selected
(50 Ω or HIGH Z), it will be 10 V maximum with 50 Ω and
20 V maximum open circuit.
4.6

Setting of parameters

The soft keys allow to use the menu field displayed. E.g. for the
waveform sine the parameters frequency, amplitude, and offset
can be varied. The amplitude may be also defined by setting the
upper (High level) and lower (Low level) levels. The selection
can be performed via the numerical keyboard and with the knob
. In addition to the parameters frequency, amplitude, and
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offset also the duty cycle and the pulse width (High/Low width)
of square waves and pulses can be defined. If the output was
activated (the LED of the OUTPUT key lights up white), any
parameter changes will be immediately available at the output
of the function generator. The waveforms triangle and pulse
allow to define the rise and fall times (Edging time). With the
waveform triangle also the symmetry (percentage of the rise
time to the period) may be adjusted.
Please note that parameters like the symmetry of the tri-
angle waveform, or the phase shift of the phase modula-
tion must be terminated with the respective unit (° , resp.
%), similar to an frequency input in Hz or Mhz. Please use
either the knob , or the unit button „MHz".
10
If a selection menu offers several pages (e.g. with the wave-
form pulse), the lowest soft key will be indicated as page 1/2.
Pushing the lowest soft key will advance to the second page,
pushing it again will return to the first page.
is active if its
Subject to change without notice
37