FUNCtion Subsystem
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This command stops and restarts the arbitrary waveforms on both channels at whatever sample rates they happen
to be set.
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If the two arbitrary waveforms have the same number of points, they will remain synchronized over multiple repe-
titions; otherwise, they will only be synchronized at the beginning and after numbers of repetitions that happen to
be multiples of the number of points in both waveforms. For example, if you synchronize an 8-point waveform and a
10-point waveform, they will re-synchronize after 40, 80, and 120 repetitions.
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This functionality is similar to using burst mode, but it operates in continuous wave mode.
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This command also works with burst, sweep, and modulation, when trying to synchronize two arbitrary waveforms.
[SOURce[1|2]:]FUNCtion:NOISe:BANDwidth {<
bandwidth
>| MINimum | MAXimum}
[SOURce[1|2]:]FUNCtion:NOISe:BANDwidth? [{MINimum | MAXimum}]
Sets bandwidth of noise function.
Parameter
Typical Return
1 mHz to instrument's maximum frequency, default 100 kHz
+6.00000000003
Set bandwidth to 20 kHZ:
FUNC:NOISe:BWIDth 20000
The Noise function produces white gaussian noise with a Crest Factor of 4.6.
The noise bandwidth is continuously adjustable to place more noise energy in the frequency range from 0 Hz to the
specified noise bandwidth frequency.
[SOURce[1|2]:]FUNCtion:PRBS:BRATe {<
bit_rate
> | MINimum | MAXimum}
[SOURce[1|2]:]FUNCtion:PRBS:BRATe? {<
bit_rate
>| MINimum | MAXimum}
Sets the pseudo-random binary sequence (PRBS) bit rate.
Parameter
Typical Return
1 mbit/s to 50 Mbits/s, default 1000 bit/s
+1.92000000004
Set bit rate to 19,200 bits per second
FUNC:PRBS:BRATe 19200
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A PRBS waveform using polynomial PN
x
is generated by a shift register of
x
bits, and the output waveform begins
with
x
sample periods of high output. Sample period is the reciprocal of the sample rate (
),
and the channel's
Sync
pulse indicates the waveform's start. For example, if the PRBS uses PN23 with sample
rate 500 Hz, the output begins with 46 ms of high output (23 x 2 ms).
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The bit rate is independent of the data sequence length.
Agilent 33500 Series Operating and Service Guide
217
