User manual

Chapter 2 Front Panel Operations RIGOL
DG800 User's Guide 2-57
Log Sweep
In Log Sweep type, the output frequency of the instrument varies in a logarithmic
fashion, that is, the output frequency changes in the way of "octave per second" or
"decade per second". The variation is controlled by "Start Frequency", "Stop
Frequency", and "Sweep Time".
When Log Sweep is enabled, you can set the following parameter: start
frequency
start
F
, stop frequency
stop
F
, and sweep time
sweep
T
. The function prototype
of Log Sweep is:
T
current
FP=
current
F
is the instantaneous frequency of the current output. The parameter
P
and
T
can be expressed with the above parameter.
sweepstartstop
TFF
P
/)/lg(
10=
)lg(/)lg( PFtT
start
+=
Wherein,
t
is the time from the start of the sweep, and its range is from 0 to
sweep
T
.
Press Menu  Sweep  "Log" to enable the log sweep. An exponential function
curve is displayed on the screen, indicating that the output frequency changes in a
logarithmic mode.
Figure 2-9 Log Sweep
Step Sweep
In Step Sweep type, the output frequency of the instrument "steps" from "Start
Frequency" to "Stop Frequency" with a stepwise increase. The duration of the output
signal on each frequency point is determined by "Sweep Time" and "Steps".
Press Menu  Sweep  "Step" to enable the step sweep. A step waveform is
displayed on the screen, indicating that the output frequency varies with a stepwise