The Smart Scan measurement mode provides three different screens (Level
Screen, Type Compensated Level Screen, and Deviation Screen).
Each screen continuously updates the measurements for all the enabled
channels in the active channel plan. Each screen displays all absolute
signal level measurements and graphical tick mark values from the current
user-selected signal level units as specified in the global configuration.
Finally, each screen contains an area referred to as the Marker Channel
Area (area above the bar or filled line graph). This area displays
information about the channel currently selected. The information
that is displayed in this area is: Overall pass/fail indicator, Channel
label, Channel type (Single, TV, Dual, Digital, or DOCSIS), and the Channel
Number. NOTE: Channel assignments are specified by the currently
selected channel plan.
SMART SCAN MAIN SCREEN
The Smart Scan bar graph view provides evenly spaced vertical bars representing
each channel along the x-axis and the deviation level on the y-axis.
NOTE: The height of the bar represents the deviation level of that
channel and a narrow vertical marker is provided to designate the
selected channel.
The Smart Scan line graph view provides a filled in line graph with each selectable
marker location representing a single channel in the result set.
The channels results are plotted such that the x-axis is frequency and the y-axis
is the measured signal deviation. NOTE: The height of the line graph
represents the deviation level of that channel and a narrow vertical marker
is provided to designate the selected channel.
The Tilt, Maximum Deviation, and Minimum Deviation are displayed on the
left side of the Channel Status area at the bottom of the screen. The
Frequency, Level, and Deviation of the selected channel are displayed on
the right side of the Channel Status area.
Graph Area
The Smart Scan Bar Graph is comprised of channels along the x-axis
and signal deviation on the y-axis. A vertical bar appears above each channel
and the height of the bar represents the signal deviation of that channel.
The Smart Scan Line Graph is comprised of channels along the x-axis
and signal deviation on the y-axis. The top of the line graph represents a
channel's deviation and the graph is filled so as to make it easy to see.
Upon entering the Smart Scan deviation screen, gray dashes will appear
in place of numeric values until a valid measurement is complete for that
value.
When the marker is on a channel, the top of the marker is dark and extends to the top
of the screen. Use the left and right arrows to move the marker. Use the left and right
arrows to move the marker. With each non-continuous key press, the marker
will increment or decrement to the next or previous channel.
When limits are enabled, two horizontal lines will be drawn on the graph at the
Max Deviation and Min Deviation limit setting. Note that the minimum deviation
limit value is the negative of the max deviation limit setting.
Channel Status Area (below the graph)
This area consists of the following:
- Tilt (dB): This is the smart scan calculated
tilt or network slope of the measurement.
- Max Dev (dB): This is the deviation of the
channel in the result set that has the highest deviation value.
- Min Dev (dB): This is the deviation of the
channel in the result set that has the lowest deviation value.
- Freq (MHz): the frequency of the selected channel
- Level (user selected units): The level measurement of
the selected channel
- Deviation (dB): The deviation of the selected channel.
The deviation of a channel is the difference between the actual measured level and the
smart scan computed expected level for the channel. Smart Scan will compute the
expected or best fit value of each channel based upon its type, the tilt present
in the system, and all the other channels present in the result set.
If limits are enabled and any limit check fails, an arrow will be displayed next
to the value that failed the limit check. The arrow will indicate if the value
was too high or low for the given limit check. If any individual channel fails its
limit checks, the overall status of the test will be a failure and an X should appear
in the upper left of the status bar. Limit checks are performed on the overall tilt
and the level and deviation of each channel in the result set.
SMART SCAN LEVEL DATA SCREEN
The Level Data bar graph view provides evenly spaced vertical bars representing
each channel along the x-axis and the signal level on the y-axis.
NOTE: The height of the bar represents the level of that
channel and a narrow vertical marker is provided to designate the
selected channel.
The Frequency and Level of the selected channel are displayed on
the right side of the Channel Status area.
Graph Area
The Level Data Bar Graph is comprised of channels along the x-axis
and signal levels on the y-axis. A vertical bar appears above each channel
and the height of the bar represents the level of that channel.
If Smart Scan animation is enabled, this will be the first of three screens viewed
when entering smart scan mode. Upon entering the Level Data screen, gray dashes
will appear in place of numeric values until a valid measurement is complete for that
value.
When the marker is on a channel, the top of the marker is dark and extends to the top
of the screen. Use the left and right arrows to move the marker. With each
non-continuous key press, the marker will increment or decrement to the next or
previous channel.
Limit check results are not displayed on this screen.
Channel Status Area (below the graph)
This area consists of the following:
- Freq (MHz): the frequency of the selected channel
- Level (user selected units): The level measurement of
the selected channel
SMART SCAN TYPE COMPENSATED DATA SCREEN
The Type Compensated bar graph view provides evenly spaced vertical bars representing
each channel along the x-axis and the type compensated signal level on the y-axis.
NOTE: The height of the bar represents the type compensated level of that
channel and a narrow vertical marker is provided to designate the
selected channel.
The Frequency, Level, and Type Compensated Level of the selected channel are displayed on
the right side of the Channel Status area.
Graph Area
The Type Compensated Bar Graph is comprised of channels along the x-axis
and type compensated levels on the y-axis. A vertical bar appears above each channel
and the height of the bar represents the level of that channel.
The Type Compensated Line Graph is comprised of channels along the x-axis
and type compensated levels on the y-axis. The top of the line graph represents
a channel's type compensated level and the graph is filled so as to make it easy to see.
If Smart Scan animation is enabled, this will be the second of three screens viewed
when entering smart scan mode. Upon entering the Type Compensated screen, gray dashes
will appear in place of numeric values until a valid measurement is complete for that
value.
When the marker is on a channel, the top of the marker is dark and extends to the top
of the screen. Use the left and right arrows to move the marker. With each
non-continuous key press, the marker will increment or decrement to the next or
previous channel.
Limit check results are not displayed on this screen.
Channel Status Area (below the graph)
This area consists of the following:
- Freq (MHz): the frequency of the selected channel
- Level (user selected units): The level measurement of
the selected channel
- Type Comp. Level(dB): The type compensated level of
the selected channel. While computing the deviation for all the channels in the result set,
smart scan will automatically compute the offset for the various types of channels in
the channel plan. The applicable computed offset is applied to all channels that are of a
different type than the channel in the result set with the lowest frequency. For example,
if the channel plan has TV channels from 55 - 500 MHz and Digital QAM 256 channels from
500 - 750 MHz, the Type Compensated values printed for the digital channels will be
adjusted upwards to match the levels of the TV channels in the system. The amount that a
channel will be adjusted based on its type is automatically computed based on the system
that is being tested. Channels that are of the same type as the lowest frequency channel
in the result set will not be type adjusted.