Rohde & Schwarz Hameg HM8150, Руководство пользователя

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Operation of the HM8150
4 Operation of the
HM8150
4.1 Display
In normal operating mode, that means no parameter is
selected, the display provides information about the fre-
quency in the left and amplitude settings in the right part
of the display. The frequency display shows 5 digits and
has a maximum resolution of 10 mHz. Amplitude values
are displayed with 3 digits and can be set to a maximum
resolution of 1 mV. The displayed amplitude values presup-
pose that the output is unloaded and must be divided by
2 to yield the correct value when terminated with 50 Ω. In
addition, the displayed values are peak-to-peak values.
With the offset function activated (OFFSET button 7 is
illuminated), the right part of the display shows the offset
voltage. The displayed values refer to an unloaded output.
After activating the pulse width setting mode (PULSE
WIDTH button
14
is illuminated) , the frequency display
shows the pulse duration. The duration of the positive
pulse or – if a negative sign is stipulated by pressing the
INVERT button
9 – the negative pulse is displayed.
In sweep mode the frequency display switches auto-
matically over to the selected sweep parameter: sweep
time (TIME), start frequency (START) and stop frequency
(STOP).
4.2 Setting parameters
After selecting the desired waveform by pressing one of
the pushbuttons FUNCTION
17
, the displayed parame-
ters can be set after activation by operating of the corres-
ponding button with the rotary knob
4
and the two cur-
sor buttons
5
or with the decadic range buttons ÷10
13 and x10 6 .
The paramter to be changed is selected by operating the
corresponding button in the PARAMETER field (OFFSET
11
, AMPL
12
, PULSE WIDTH
14
, FREQ
15
or the AMP).
The button is illuminated, when the parameter can be
changed. By operating the rotary knob
4
the value of the
digit underlined by the cursor is modified. If the cursor un-
derlines a blank position, it is considered as 0 and can be
changed by turning the rotary knob
4 to the desired va-
lue. The cursor is shifted to another position with the two
cursor buttons
5
. Turning the rotary knob
4
incre-
ments or decrements the value depending an the direction
the knob is turned.
The range can be changed by using the two range but-
tons ÷10
13 and x10 6 . The parameter is increased or de-
creased by the factor 10. Thereby precise decade shifts
can be done. An unproper value is announced by a war-
ning signal.
When selecting the parameter PULSE WIDTH
14
, this but-
ton is illuminated and the pulse width can be set by opera-
ting the rotary knob
4
and the two cursor buttons
5
or with the decadic range buttons ÷10 13 and x10 6 .
If it is additionally desired to superimpose the output sig-
nal with an offset, the value of the offset can be varied by
selecting the OFFSET function
7
by using the rotary knob
4
and the two cursor buttons
5
or with the decadic
range buttons ÷10
13
and x10
6
.
4.3 Waveforms
The HM8150 offers six different waveforms, of which four
waveforms have fixed shapes that cannot be changed.
Only the frequency and amplitude of the sawtooth (ramp),
triangle, sine and square wave signals can be varied. The
pulse function permits the pulse width to be modified, too.
The arbitrary function can be defined by the user (within
the the specifications of the HM8150).
❙ Sine wave
The maximum frequency is 12.5 MHz.
❙
Square
The maximum frequency is 12.5 MHz. The rise and fall
time is <10 ns.
❙ Triangle
The maximum frequency is 250 kHz. The linearity is better
than 1%. The maximum voltage is 20 V
pp
(no load).
❙
Pulse
Positive and negative pulses can be generated with a
maximum frequency of 5 MHz. The pulse width can be set
between 100 ns and 80 s. The largest settable duty cycle
is 80%. The rise and fall times are the same as given for
the square wave signal. The output amplitude can be set
to between –10 V and +10 V.
❙ Sawtooth
The frequency can be changed in the range of 10 mHz to
25 kHz.The linearity is better than 1%. The maximum
output voltage is 20 V
pp
(no load). A positive or negative
ramp can be selected by operating the button INVERT
9
.
❙ Arbitrary
The maximum signal frequency is 250 kHz at a sampling
rate of 40 MSa/s. The resolution of the user-defined signal
is 1024 points for the 10 bits resolution and 4096 points
for 12 bit resolution. For more details please refer to
paragraph Arbitrary FUNCTION.
4.4 Operating modes
The HM8150 offers different operating modes.In addition
to the standard operating mode ”continuous“, signals can
be generated in response to a trigger event (triggered) as
well as in response to a gating signal (gated). The opera-
ting mode can be selected with the buttons GATED
18
and
TRIG‘d
19
. A luminous button indicates the actual opera-
ting mode. If none of the both buttons is illuminated, the
function generator is in continuous mode.
The following combinations of operating modes are
possible: