Anritsu ML2430A - Manual (Page 77)

The unique method of range changing applied in this
mode means that the change between range 1 and 2 is
effected in less than 2
ms. In most cases it is not notice-
able, although there may be a slight discontinuity.
Due to the range-change method, if a triggered signal is
not repetitive the range change may not settle instantly,
and the displayed result may be in error. This is generally
true for x-axis times of less than 6 ms where it takes more
than one pass to completely update the display.
Control of
x-axis - Width of
Profile - Sample Time
The control of the time-frames over which the PROFILE is gathered is very pre-
cise, but there are certain restrictions. With care it can be used to display the pro-
file of signals down to typically 100
ms or better.
1. Select
SYSTEM|PROFILE. The first two items in the menus have already been
covered (selection of channel 1 or 2, and the method of display, min max). The
last two selections control the data collection PERIOD (the time span of the win-
dow). The default period is 10 ms, and it can be adjusted down to 100
ms and be-
low. If you are still displaying the 1 kHz square wave, enter a period of 3 ms. The
display will zoom in to show more detail of the pulses.
NOTE
Thermal sensors have rise and fall times of <4 ms. Do not
use a thermal sensor for fast signal profiles.
Typical MA2470A and MA2440A Series sensors have rise
times of <4
ms. Fall time is typically <10 ms, except at low
power levels. Consider this when looking at fast signals.
2. Note that the cursors have remained at their set positions in time, that is, when
altering the time axis the cursors stay at their set positions in terms of time - NOT
POSITION ON THE SCREEN. This is very important when measuring specific
points or peaks in a signal.
3. By altering the DELAY parameter, the PROFILE can be made to look at a seg-
ment of time long after or very close to the trigger point. That is, by setting the
DELAY to 100 ms, the PROFILE will show the 100th pulse (and onwards) of a 1
kHz square wave. By setting to ZERO, the profile will show data immediately after
the trigger has occurred. This is the DISPLAY TRIGGER DELAY and is denoted
by a small ‘x’ on the PROFILE display. This marks the point on the display where
data is taken at the time DISPLAY TRIGGER DELAY is placed. For example, for
the 1 kHz square wave, the pulse edge would occur at the ‘x’ point whenever the
DISPLAY TRIGGER DELAY is a multiple of 1 ms. The x-axis nomenclature al-
ways denotes this point with a time of ZERO (t=0), this allows the user to always
consider time intervals relative to the display trigger which is usually the point of
interest.
5-14 ML2430A OM
PROFILE OPERATION MODE PROCEDURES