User`s manual

Sweep Time The number of frequencies (points) in a sweep and the number of frequencies
in a frequency list change the duration of the sweep or pass through the list.
The relationship between the sweep or list time (
[SOURce:]SWEep:TIME), the
time between frequencies (
TRIGger:SWEep:TIMer), and the number of
frequencies (points) is shown below:
TIME =
TIMer * (points - 1)
Changing the number of points keeps the value set by the last command sent
(either
[SOURce:]SWEep:TIME or TRIGger:SWEep:TIMer) and changes the
other. Changing
TIME or TIMer affects the other.
Sweep Advance Source The source which advances the sweep or list to the next frequency is set
with the
TRIGger:SWEep:SOURce command. The available sources are:
• BUS – The GPIB Group Execute Trigger (GET) command or the
IEEE-488.2
*TRG common command.
• HOLD – Suspend sweep or frequency list advance triggering.
Advance to the next frequency (sweeping or in a list) using
TRIGger:SWEep:IMMediate.
• LINK – The next valid start arm advances the sweep or list.
• TIMer – The [SOURce:]SWEep:TIME and/or TRIGger:SWEep:TIMer
commands control the sweep and frequency list advance timing
(default source).
• TTLTrg0 through TTLTrg7 – The VXIbus TTL trigger lines.
More information on the sweep advance source can be found in Chapter 5,
“Arming and Triggering”.
Specifying a
Sweep Time
The sweep time (set by [SOURce:]SWEep:TIME) is the period from the
generation of the first frequency in the sweep or list to the generation of
the last frequency (see below).
The duration (t) of each frequency (except the last (f
n
)) is:
specified sweep time/(frequency points - 1)
For multiple sweeps or repetitions through the list, the duration of the last
frequency (f
n
) is also t. To maintain a constant rate between sweeps or
repetitions, the duration of f
n
must be accounted for as follows:
f
1
f
2
f
3
f
4
f
n
Sweep Time
t
t
t
t
158 Sweeping and Frequency-Shift Keying Chapter 4