Tektronix 222 Operator's Manual page 98

More On How It Works-222 DSO Operators
channel that is "OFF" take effect when the trace is
turned back on.
6.5
DEFAULT ACQUISITION MODES
The default modes possible are: SCROLL, SC AN-ROLL-SCP
SCAN-ROLL-SCAN-SAVE, RECORD, and REPETITIVE.
As the SECIDIV switch is rotated, the method of acquisition changes
at predetermined settings. In general, the switching is as follows. At
the very slow sweep speeds (20 sec to 0. I sec per division) a version
of ROLLmode (dependent on the Trigger MODE in effect) is selected.
When the sweep speeds are faster (50 ms to 5 ~s per division), full-
record sampling is done. At the fastest sweep speeds (2 ps to 50 ns
per division), equivalent-time sampling of the applied signal(s)
occurs. Table 6-2 shows this information.
SCROLL Mode: In NORM and ENV acquisition mode, with either
AUTO LVL or AUTO BL Trigger Mode selected, the display mode for
SECIDIV settings of 20 second per division to 0.1 second per division
is Scroll mode (continuous ROLL). No trigger is accepted, and each
data point is displayed as it is acquired, starting with the first data at
the left end of the trace. Only valid data points are displayed, and the
trace is blanked at the end of the valid points. After the display is
filled, the data points are shifted left one position for each new data
point acquired. The new data point is added at the first position at the
right end of the trace, giving the effect of scrolling the waveform
across the display area. Pressing the INIT button at any point restarts
the acquisition and display. AVG and CONT ENV acquisitions mode
displays do not scroll; they are updated as full-records only. At the
slower SECIDIV settings you may prefer to use NORM or ENV acqui-
sition mode for your application. Also, if NONSTORE display mode is
selected, the trace will be blanked immediately after the display up-
dates. Use STORE mode to retain the waveform displays between
updates.
REV JUN
1989