Texas Instruments MSP430FR6047, User Manual, Page: 7 / 19

transducers will affect how much additional margin is required to address shifts in the signal due to temperature
and flow variations. For example, a pipe with an ultrasonic path of 19 cm might require 10 µs of additional
capture time preceding the signal.
The "Number of Pulses" affects the strength of the signal and the standard deviation of the dToF waveform at
zero flow. An increase in the number of pulses should give a lower standard deviation in dToF. There is also a
tradeoff with respect to power consumption and interference. As the number of pulses is increased, earlier parts
of the excitation signal can interfere with the latter part of the transmitted signal when traveling along alternative
ultrasonic paths. The default setting for this parameter should be used as a starting point.
The "UPS and DNS gap" is the time between upstream and downstream measurements. The time required
between measurements is governed by the ultrasonic propagation time. Larger pipes require a larger gap. There
also needs to be enough time between UPS and DNS excitations to ensure the DNS signal does not have
interference from residual reflections of the UPS signal. The default setting for this parameter should be used as
a starting point.
The "UPS0 to UPS1 Gap" is the time between the end of a set of measurements and the beginning of the next
set of measurements. Power consumption is directly affected by the measurement rate. A UPS0 to UPS1 gap of
1 second consumes roughly twice as much power as a UPS0 to UPS1 gap of 2 seconds. The default setting for
this parameter should be used as a starting point.
Set the "Meter Constant" to give a volumetric result that is consistent with a reference meter under flow.
Specifics on the calibration procedure for determining the meter constant can be found in the "Calibration User’s
Guide". The default setting for this parameter should be used as a starting point.
After the desired set of configuration parameters has been set, you should click the "Request Update" button to
send these parameters to the platform. The "Save Configuration" button will save the current set of parameters
to a file. The "Load Configuration" button loads a previously saved set of configuration parameters from a file.
The timing diagram for the configuration can be seen at the bottom of the GUI screen (see
Figure 4-3 ). The
timing diagram represented in this figure is representative and is not exact.
Figure 4-3. Configuration Timing Diagram
www.ti.com USS GUI
SLAU810B – SEPTEMBER 2019 – REVISED SEPTEMBER 2020
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