Download Display the Test Result of the Digital Circuit with Graph

Display the Test Result of the Digital Circuit with Graph
Introduction:
The digital multimeter, or DMM, has become a necessary instrument for electronic test benches of
all types. In developed countries, the digital multimeter is used in roughly 70-80% of applications
while the older analog meter is used much less often. But the typical DMM has had some of its
own shortcomings: For example, the analog meters allowed the user to “peak” their test devices by
watching for a positive or negative “dip” in the meter’s movement. In addition, there are often
cases where it would be advantageous to make readings of two different parameters at the same
time; for example, Voltage and Current. It is also handy to have quick access to statistics on our
measurements or a trending graph, similar to a strip chart recorder display.
With computer interface ports such as LAN, GPIB or USB we can send our data readings to a PC
for storage and further calculations. This can take some time. However, with SIGLENT’S
SDM3055 Digital Multimeter further data calculations can be performed in the DMM without
having to send the data to a PC. With the benefit of its 4.3 inch color TFT-LCD display and a
resolution of 480 * 272, the user can display two separate parameters, statistics, histograms, trend
charts, Pass/Fail, etc.
Four different display modes provide the user with fast and important data.
histogram
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bar graph
Trend
data
Simple and intuitive user interface allows for quick and easy data interpretation.
By clicking a button or two on the SDM3055’s front panel the user can easily access structured
interfacing and arithmetic menus. And by using the 6 soft-keys located below the display,
navigation is made even easier.
Figure 1. Display: offers four different displays.
Large multi-function Display
The horizontal bar-graph function allows the user a quick view - if and how much the measured
value is changing. This is often more handy than trying to interpret the direction and magnitude
changes in a numerical read-out. This bar-graph can also be used with the Limit function or when
using the Math features.
Figure2. bar graph can help you to see the measurement results rapidly
Powerful Trend Graph
If one expects the data to remain relatively constant then a measurement can be made only one
time. More typically, however, the measured value will drift over time, be effected by other
parameters or change due to some external disturbance. With the SDM3055(A) trending graph the
user can see if and how the data has been changing over the last minute or since the last Clear. As
an example, this function could be used to monitor the output of a power supply as load conditions
change. Or multiple DMMs could be used to simultaneously graph Voltage, Current, and
Temperature changes over time.
Figure 3.the trend shows the measurement result change over time.
Histogram Function Provides Quick Statistical Information
If the lowest measured values are constantly changing, for example, we want to know
what the nature of this change is. With the Histogram function we now see the
statistical variation of our measured values. Calculated values such as mean, standard
deviation, and distribution shape are all critical information used in understanding
these changes. The Histogram scale can be set to Automatic or to a Manual value of
10, 20, 40, 100, 200 or 400 depending on our requirements. We can also capture
values outside the range of our display such as the occasional power glitch or other
external interference.
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Figure 4 .histogram displays the distribution of the of measured values.
User interface display adds arithmetic and statistical functionality. Statistical functions can be
used both with displayed values but also with trend graphs, histograms, and bar charts.
Figure 5 shows the DC Voltage reading plus the statistical values to help in determining
measurement point stability.
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Figure 6: Showing statistics and histogram functions on single display.
Figure 7: Displaying statistics and trend graph simultaneously.
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Figure 8.Using statistical display and bar graph display.
Limit Test
The Limit function provides a visual and audio indication that alerts the user when a specific
preset condition has been exceeded. For example, if one was monitoring the temperature of a
circuit prototype in a hot dip tank, the Limit function would alert you before an expensive
prototype might be damaged. The Limit function can be used in all four test modes.
Figure 9: The Limit function in the normal digital mode.
Figure 10: Showing the Limit function when in the Trending display mode.
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Figure 11. This example shows the Limit function used in the Histogram function display.
Figure 12. Using the Limit function in the Histogram function display mode.
The following illustrates the powerful graphics capabilities of the SIGLENT SDM3000
multimeters:
A manufacturer of battery charging systems needs to run a test to determine the minimum use
of battery power in order for their system to smoothly shut down or restart the charging circuit.
Because the battery charger does not utilize a buffer circuit the charger should not respond
instantaneously to voltage changes. In order to simulate the charging circuit the design team uses a
triangle waveform provided by the SDG5000 arbitrary / function generator.
Engineers use the SIGLENT SDM3055 to measure the on / off output voltage of the detector
circuit as well as the Histogram mode to display the results. Looking at the frequencies of 1 Hz or
less, the display shows the histogram distribution with the appropriate results. However, when
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interference occurs the circuit reacts abnormally, displaying an intermediate output value. From
the display we can see at what frequencies this occurs and design a simple cut-off frequency filter
in the circuit to solve the problem.
Ramp
standard histogram
histogram with noise
In conclusion:
The SDM3055 multi-meter with its data analysis features has shown us the unique
advantages of this meter. Ordinary multimeters can display simple values only and using a an
external PC can slow down the process and requires additional programming. However, by using
the SIGLENT SDM3055 digital multimeter, a few keystrokes will access powerful built-in
arithmetic and statistical functionality. The user need not plot readings and calculate statistical
data as this is performed within the unit itself.
SIGENT’s core business is test & measurement instrumentation, adhering to our core
competencies and using strict quality control and technological innovation, the SIGENT
Technologies brand of products will continue to grow as your best choice and trusted partner!
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