Setting Sweep Mode, Ramp Time And Source - Metrix GX1010 Notice De Fonctionnement

sweep started at each frequency change; it is therefore faster to make changes with the
sweep off. The MARKER frequency, however, can be changed without interrupting the
sweep.
A second marker is also displayed at the frequency set on the main menu, i.e. at the
frequency set for the generator in non-sweep mode. This offers the advantage of a marker
adjustable from the same menu used to control amplitude, offset, etc.
The marker signal is output from the rear panel TRIG/SWEEP OUT socket, see
Connections for Sweep Operation section. The output is low (0V) for the duration of the
sweep, with narrow 1V pulses at the marker frequency. Note that the marker pulse width is
that of the duration of the frequency step with the closest value to the marker frequency.
This means that sweeps with few steps will have wider markers than those with many
steps, see Frequency Stepping Resolution section.

4.3.4. Setting Sweep Mode, Ramp Time and Source

Pressing the FIELD keys to move the cursor through each editable field of the first page of
the sweep menu eventually steps the cursor onto the second page shown below.
Pressing the left FIELD key with the cursor in the first (MODE) field will return the edit
cursor to the last field on the first page of the sweep menu. Pressing the right FIELD key
will step the cursor through all the editable fields up to TRIGger SouRCe; one more press
returns the cursor to the first field of the first page. Pressing ESCAPE always exits the edit
menu and returns to the Main menu.
With the edit cursor in the MODE field, alternate presses of the DIGIT keys, or turning the
rotary control, will set the sweep direction to BEGin-END or END-BEGin. There are no
restrictions on the BEGin and END frequencies, e.g. the BEGin frequency can be higher
than the END frequency, so the MODE field simply provides an easy way to reverse the
sweep direction.
With the edit cursor in the LAW field the sweep can be changed from LINear to
LOGarithmic. With LAW=LIN set, the frequency changes linearly with time across the
sweep; with LAW=LOG set, the frequency changes exponentially with time across the
sweep. The term 'log sweep' is a convention; with the start frequency lower than the stop
frequency (the usual mode of operation) the mathematical relationship of frequency to time
is actually anti-log.
The sweep rate is set with the cursor in the RAMP TIME field; ramp time can be set with 3
digit resolution from 0.01s (10ms) to 999s. The choice of ramp time affects the number of
discrete frequency steps in the sweep; faster sweeps will have fewer steps, see Frequency
Stepping Resolution section.
The trigger mode of the sweep is set with the cursor in the TRIGger SouRCe field; the
options are CONTINUOUS, EXTernal and MAN/REMOTE. In CONTINUOUS mode the
sweep starts simultaneously with the high-to-low transition of the TRIG/SWEEP OUT
signal; the sweep starts with the phase at 0° and at the output level set by the DC offset. At
the end of the sweep the signal returns to this DC offset level and the TRIG/SWEEP OUT
signal simultaneously goes high again. After a delay long enough for an oscilloscope to
retrace, for example, the cycle repeats.
In EXTernal mode a trigger signal is connected to the front panel EXT TRIG socket. A
sweep starts typically 200-800µs after the rising edge of the trigger signal; the sweep is
completed before another trigger edge is recognised and a new sweep initiated. The
GX1010
MODE=BEG-END LAW=LOG
RAMP TIME=0·05 S
TRIG SRC=CONTINUOUS
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