User`s manual

Reference
Oscillator Sources
• The USER function can use any of the reference oscillator sources
selected by the
[SOURce:]ROSCillator:SOURce command. The
reference oscillator sources are:
INTernal[1] – 42.94967296 MHz (power-on value)
INTernal2 – 40 MHz
CLK10 – 10 MHz (the VXIbus CLK line)
EXTernal – User provided value (the front panel “Ref/Smpl In” BNC)
ECLTrg0 or 1 – User provided value (the VXIbus ECL trigger lines)
• If using either the EXTernal or ECLTrg0 or 1 reference oscillator
sources, enter the source frequency to the AFG using
[SOURce:]ROSCillator:FREQuency:EXTernal <frequency>.
• For best frequency linearity, use the 42.9 MHz (i.e., INTernal[1])
reference oscillator source with the DDS (frequency1) frequency
generator. This combination provides .01 Hz resolution. For higher
frequency values, use the 40 MHz (i.e.,
INTernal2) reference
oscillator source with the Divide-by-N (frequency2) frequency
generator. Use the
EXTernal or ECLTrg0 or ECLTrg1 sources for
custom frequency values. However, any reference oscillator source
can be used with any frequency generator.
Sample Sources
• The USER function operates with any of the sample sources selected
by the
TRIGger:STARt:SOURce command. The INTernal[1] source
automatically selects the DDS frequency generator. The
INTernal2
source selects the Divide_by_N frequency generator. The other
sources are not used with any frequency generator. The sample
frequency thus depends on the externally generated sample signal.
The different sample sources are:
INTernal[1] (power-on value; selects the DDS frequency
generator)
INTernal2 (selects the Divide-by-N frequency generator)
BUS (the GPIB GET or *TRG commands)
EXTernal (the front panel “Ref/Smpl In” BNC)
ECLTrg0 or ECLTrg1 (the VXIbus ECL trigger lines)
HOLD (suspends sample generation)
TTLTrg0 through 7 (the VXIbus TTL trigger lines)
Chapter 3 Generating Arbitrary Waveforms 115