ATS-2 Basic Extensions.vp

ATS2.Inst.FFT.TrigSource Chapter 28 FFT Spectrum Analyzer
apbFFTChBFixed
Ch. B Fixed:
apbFFTExternal
Trig In (Ext): The External selection refers to pin 3 of the
15-pin D-sub connector on the rear of the DSP module. This
source is operational only with the SYS-2300 series Dual
Domain units. If pin 3 is high (or open circuit, in which case
it is pulled high by an internal pull-up resistor), triggering
occurs at the next digital sample. Pulling pin 3 low from an
external device holds off triggering, with acquisition being
triggered on the next sample after pin 3 is pulled high. This
External selection is unaffected by the Slope buttons.
apbFFTDGen
Digital Gen: The Digital Generator selection functions only
on Dual Domain units (SYS-2300 series). If the Digital
Generator is generating any of the waveforms selectable in
the Waveform field, a Digital Generator trigger occurs at
each zero crossing of the waveform, positive-going or
negative-going as selected by the Slope buttons. If the
Digital Generator is generating a signal from a waveform
file, a Digital Generator trigger occurs as the first sample is
read from the waveform file.
apbFFTAGen
Analog Gen: The Analog Generator Sync selection is the
same signal as at the Generator Aux Signals Sync Output
BNC on the front panel of ATS. This signal is a squarewave
at the Analog Generator frequency in sinewave and
squarewave waveforms, the envelope of the burst signal in
all Burst waveforms, a squarewave at the lower IMD
frequency in SMPTE IMD waveform, a squarewave at 1/2
the frequency spacing in CCIF IMD waveform, the
squarewave IMD signal in DIM IMD waveform, and a pulse
at the pseudo-random repetition rate in Pseudo noise
modes. There is no signal in Random noise modes.
apbFFTACMains
Line (Mains): the power line frequency.
AP Basic Extensions for ATS-2 Page 28-13