2.0 Basic Instrument Concept; Functioning Principle; Signal Waveforms; Sawtooth - Hameg HM 8131-2 Manual

2.0 Basic instrument concept

List of abbreviations and symbols:
V peak-to-peak voltage
pp
V peak voltage
p
V root-mean-square voltage
rms
DDS Direct digital synthesis
Sin

sine

Tri

triangle

Sqr

square wave

+rmp positive ramp, sawtooth
–rmp negative ramp. sawtooth
Spc spectrum; selection of an arbitrary signal or noise

Functioning principle

The HM 8131-2 is a direct digital synthesis signal generator . All
possible waveforms are stored in an EPROM or they are calculated.
Not all waveforms are available up to 15 MHz due to the limited
speed of converters, memories and of the processor.

Signal waveforms

The HM 8131-2 offers the choice of 6 predefined waveforms and
of an arbitrary waveform. The frequency and the amplitude of
sawtooth, (pos. and neg. ramp) , triangle, sine , and square wave
are selectable. The amplitude of the functions white noise resp.
pink noise is selectable. The arbitrary function may be freely
defined given the limitations of the instrument, a 4 K and a 16 K
memory are provided.

Sawtooth

– Due to the digital principle of generation the frequency
range is limited to 100 µHz to 100 kHz
– Linearity error <1%
– Max. output voltage 20 V
– The ramp may be positive or negative
– Duration of negative or positive slope is appr. 45 ns.
Triangle
– Max. frequency 1 MHz
– Linearity error <1%
– Max. output voltage 20 V
Sine
– Max. frequency 15 MHz; resolution 100 µHz
– Max. output voltage 20 V
Square wave
– Max. frequency 15 MHz
– Resolution 100 uHz
– Rise time < 10 ns
– Max. output voltage 20 Vpp no load

Arbitrary

– Max. frequency is 10 MHz at 40 MSa/s
– Amplitude resolution is 12 bits
– 4 K and 16 K memories are available
– a 4 K non-volatile and a 16 K volatile memory are provided
Subject to change without notice
no load
pp
no load
pp
no load
pp
– The signal is filtered using a 7
frequency of 10 MHz
– resolution 100 µHz
3.0 Introduction to the operation of
HM 8131-2

First time operation

Please note the following guidelines especially at first-
time turn-on:
– The line voltage selector
the correct fuse is installed.
– The mains connection is either to a 3 terminal connector
with a safety ground terminal or via an isolation transformer
of class 2.
– No visible damages to the instrument
– Power cord undamaged
– No loose parts inside
– No test or other cables connected to the output terminal
. Check whether the LED adjacent to the output on/off
switch is extinct.
– First set the desired output signal at
– Check this signal by using a HAMEG scope
– A false output amplitude may damage any test,
measurement or other circuit connected to the output.

Self test

After turn-on the display will show in turn the following:
Instrument designation:
The display shows type and version number, e.g. HM 8131-2
V 3.01:
*FUNCTION GENERATOR*
** HM8131-2 V3.01 **
Date:
The display shows the time and date as they are stored in the
instrument:
FRIDAY 24/01/03
16:55
Interface:
The interface type is displayed, RS-232 standard, with option
HO88-2 also IEEE-488, the address is shown :
Communication Device
** default rs232 **
Reference frequency:
The display will indicate whether the instrument is programmed
for the internal or an external reference frequency:
Frequency Reference
Internal
Introduction of the operation
th
order Bessel function with a
is in the proper position, and
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