Hameg HM 8131-2 Manual page 62

Main menu 1 and functions
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 specifications for
accuracy and amplitude as outlined in the instrument
specifications.
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.
HM 8131-2 as the source of reference frequency
10 MHz-Referenz
10 MHz
IN / OUT
A HM 8131-2 can deliver the reference frequency for
STOP
other HM 8131-2. The HM 8131-2 which is destined as
the source is programmed in the menu „OPTIONS
MENU 3" for [Int]. The other HM 8131-2's are
programmed in the same menu for [Ext]. All
instruments are connected in parallel with their
terminals [10 MHz IN/OUT].
TiPP
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 Master-Slave operation
is mandatory.
STOP
Master – Slave operation
10 MHz-Referenz
62
[10 MHz IN/OUT]
10 MHz 10 MHz
IN / OUT IN / OUT
Up to 3 instruments may be synchronized this way. In the menu
"MULTI-DEV SYNC" [Sync] must be chosen. The definition
whether an instrument should be master or slave is done in
"Device configuration" where "MS–" or "SL+" designates master
resp. slave.
Example: Switching from master to slave
Switching from Master to Slave
Mt: 1.0000000 kHz
Sin Tri Sqr -->
*** MAIN MENU 1 ***
Sweep Arb Mode -->
** WORKING MODE **
Cnt Trg Gat Sync
** MULTI-DEV SYNC **
Master Pulse Slave
** MULTI-DEV SYNC **
Master Pulse Slave
Push button [Prev] twice
Sl: 1.0000000 kHz
STOP
Sin Tri Sqr -->
In place of Fr for free-running the basic menu will show
Mt for master and SL for slave.
TiPP
Selection of as well as leaving the synchronous
master-slave mode is only possible in the menu
"Working mode" by calling "Sync".
If it is desired to operate several generators with the
STOP
same frequency, all generators must use the same
reference frequency. In spite of the high accuracy of the
individual oscillators synchronisation is indispensable if
true coincidence is required. Synchronisation my be
STOP
achieved either by using an external reference (10 MHz)
for all generators or by naming one as the master
reference and synchronize the others (slaves) to this
one. Synchronization will guarantee identical phase
between all generators, but the phase or time difference
between the synchronization signal and the output
TiPP
signals can not be influenced.
Functional description of master – slave operation
Master – slave operation means defining the internal oscillator
frequency of one generator (master) as the reference for the
others (slaves). All slaves deliver signals identical to that of the
master and locked in phase. However, there will be a constant,
frequency-dependent phase shift between master and slaves.
Subject to change without notice