2-4
IM 701240-01E
Record Length
The term
record length
normally refers to the number of data points acquired per channel
in the acquisition memory. The record length changes when you change the record time
or sample rate (see appendix 1). The following equation holds: record length = record
time
×
sample rate. The maximum record length of the SL1400 is 50 MW. The measured
waveform signal of a single channel can be acquired up to the maximum record length of
50 MW when only a single channel is displayed.
The record length that is stored in the acquisition memory and the record length of the
displayed waveform are the same.
Display along the Time Axis
There are 10 divisions along the time axis, and 1001 points (logical number of points, not
the dots on the screen) are used to draw the waveforms. Therefore, if the record length
is exactly 1 kW (the number of acquired data points is 1001), the waveform is displayed
using 1001 points. However, if the record length is greater than or equal to 2 kW, the
maxim and minimum values are determined (P-P compression) and aligned at the same
time position (total number of points: 2002) to draw the waveform.
1001 points*
0
1000
Sampled data
Time axis
Record length
Record length
<P-P compression display>
Maximum value
Minimum value
* 1001 points is a logical number
of points. On the screen the
data is compressed to 651 dots
(when the zoom waveform area is
expanded to 751) and displayed.
Vertical axis
Zooming Horizontally and Drawing Waveforms
The SL1400 is capable of expanding (zooming) the waveform horizontally (see page
2-34). When the zoom rate of the waveform is increased, the number of displayed
points decreases. The waveform is displayed P-P compressed until the number of
display points falls to 2002 points. When the number of displayed points falls below
1001, the waveform can no longer be displayed using continuous lines. In this case,
the display data is interpolated using the display interpolation function (see page 2-33)
so that the number of displayed points is 1001 points.
2.2 Setting the Horizontal and Vertical Axes