Hameg HM8131-2 Handbuch Seite 54

M a i n m e n u 1 a n d i t s f u n c t i o n s
Triggering on the falling edge
The negative slope of the trigger signal will start the sine, the
last sine period will be completed after the rising slope of the
trigger.
Burst mode
Burst can be generated either by an external trigger signal or
via an interface. If a burst is programmed in the arbitrary mode
the trigger signal must be short than the signal period so that
only one period is generated.
Gated mode
By pressing (Gat) the "GATE CONTROL" menu is called. Also
here fi rst + or – slope is selected. In gated mode the output
signal is controlled by a gate signal applied to the TRIG.INP
on the front panel. This mode is asynchronous, i.e. the output
signal may start at any time during its period.
Gate (High)
The output signal will be present as long as the gate signal will
be High (TTL levels). The picture illustrates how the signal at
any level.
52
Subject to change without notice
Gate (Low) The output signal will be present as long as the gate
signal is low (TTL levels).
Reference frequency operation
The standard HM 8131-2 oscillator is a stable crystal type. As an
option HO86 a temperature-controlled TCXO is available which
-7
features 5x10 . This option must be installed in the factory or
by the HAMEG service.
A further increased frequency stability is attained by using an
external standard connected to the terminal
on the rear panel.
The external reference must comply with the specifi cations
for accuracy and amplitude as outlined in the instrument
specifi cations.
The menu OPTIONS MENU 3 allows the selection of reference
frequencies by choosing [Ref] either [Int] or [Ext]. The selected
source will be shown each time the instrument is turned on.
HM8131-2 as the source of reference frequency
10 MHz
IN / OUT

A HM8131-2 can deliver the reference frequency for
other HM8131-2. The HM8131-2 which is destined
as the source is programmed in the menu OPTIONS
MENU 3 for [Int]. The other HM8131-2's are pro-
grammed in the same menu for [Ext]. All instru-
ments are connected in parallel with
their terminals
HINT
If all instruments are set for identical signals they
will in fact deliver identical signals derived from the
same reference frequency, however, the signals
are not synchronous! In order to realize this Ma-
ster-Slave operation is mandatory.
STOP
[10 MHz IN/OUT]
10 MHz-Referenz
10 MHz 10 MHz
IN / OUT IN / OUT
[10 MHz IN/OUT].