System Functional Overview
CSA 803C Service Manual
3Ć5
User control of the CSA 803C is primarily through the following three front
panel controls:
H the frontĆpanel majorĆmenu buttons
H the touch panel
H the multifunction knobs
The major menu buttons are the top level menu selections for the instruĆ
ment. Touching an icon, menu item, or waveform selects that particular icon,
menu item, or waveform, respectively. The multifunction knobs control the
function of the particular item that is selected.
The I/O block provides a GPIB port, RSĆ232ĆC port, and a PRINTER port for
interfacing various I/O devices to the instrument.
The display subsystem provides all visual output to the user. This includes
not only data output such as waveform traces, graticules, axes, and annotaĆ
tion, but displays supporting the human interface as well (which includes
menus, labeling for touch panel input, and an interactive output to assist in
operating the system; that is, the current modeĆsetting information).
The CSA 803C uses a custom vertical rasterĆscan display that provides
excellent resolution for both waveform display and text. The display system
produces the display by the following:
1. transferring waveform data from the Waveform Memory
2. compressing it into 512 horizontal pixels
3. converting it to a format compatible with the vertical rasterĆscan display
The Waveform Compressor takes waveforms with more than 512 data points
and compresses these points into 512 groups. For example, for a 1024Ćpoint
waveform, each group would contain two points; for 2048Ćpoint waveforms,
each group would contain four points. The Waveform Compressor finds the
largest and smallest vertical value in a group of points and then draws a
vector between the maximum and minimum Ċ even in dots" mode. The
only difference between dots and vectors is that in vector mode the vectors
are extended vertically to meet the vector on the next scan line.
Front Panel Controls
I/O Block
Waveform
Compressor and
Display Control Block