User`s manual

• TTLTrg0 through 7 – The VXIbus TTL trigger lines.
INTernal[1] is the source selected at power-on or following a reset,
but is specified in the programs to emphasize that sweeping,
frequency lists, and frequency-shift keying are only allowed when
INTernal[1] is the source.
AFG Frequency
Modes
There are four frequency “modes” available using the INTernal1 sample
source (DDS timebase). The modes selected by the
[SOURce:]FREQuency[1]:MODE command are:
• CW | FIXed – single frequency mode
• FSKey – frequency shift keying mode
• LIST – frequency list mode
• SWEep – frequency sweep mode
Frequency Range:
Sweeping and
Sampling
The frequency range for sweeping or sampling depends on the reference
oscillator used. However, for the
INTernal1 42.94967296 MHz oscillator,
the range for swept sine, square, triangle, and ramp waveforms, and the
swept sampling range for arbitrary waveforms is 0 Hz to 10.73741824 MHz.
Frequency Range:
Frequency Lists
and FSK
The maximum number of frequencies in a frequency list is 256. The range
of frequencies allowed in a frequency list or for frequency-shift keying
depends on the output function:
• Sine Wave and Arbitrary Waveforms: The minimum frequency is
0 Hz; the maximum frequency is the selected reference oscillator
frequency divided by 4.
• Square Waves: The minimum frequency is 0 Hz; the maximum
frequency is the selected reference oscillator frequency divided by 16.
• Ramp and Triangle Waveforms: The minimum frequency is 0 Hz;
the maximum frequency is the selected reference oscillator
frequency divided by four multiplied by the number of waveform
points (Rosc/(4*npts)).
Frequency Doubling For all waveforms except sine waves, the sweeping or sampling range can
be doubled using the
[SOURce:]FREQuency[1]:RANGe command.
Frequency doubling is enabled by specifying a range that is greater
than the maximum “undoubled” frequency allowed for a given
waveform. The maximum undoubled frequencies for the various
waveforms are given below.
• Arbitrary Waveforms: The maximum undoubled frequency is the
current reference oscillator frequency divided by 4.
• Square Waves: The maximum undoubled frequency is the current
reference oscillator frequency divided by 16.
Chapter 4 Sweeping and Frequency-Shift Keying 155