artisan DAC128V, Hardware Reference Manual

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TYPICAL APPLICATIONS
Copyright 2001 B-1 DAC128V HARDWARE REFERENCE
B.1 Overview
Systran extends an open invitation to all users to freely submit their applications that
might, or do, use the DAC128V IP Module to solve a problem. This section of the
manual will be revised periodically to include new application ideas for all users to
consider. Help advance the level of technology by participating with the Systran team,
while simultaneously publishing your ideas.
Submission constitutes permission to publish without additional consent or
compensation, and Systran reserves the right to modify submissions to provide for more
generic appeal, when necessary.
B.2 A Short Glossary Of Analog Signal Applications
The following typical applications were developed by using one or more channels on the
DAC128V IP Module. Most of the analog output voltage reference configuration
operations can be performed (within limits) by proper connections and software
manipulations.
.
NOTE: If the DAC128V is to be used with the voltage range at +10 V and/or -10 V,
the user must supply the +15 V power source to the I/O connector and make the
appropriate jumper selections. This is necessary due to the onboard DAC’s requiring
the reference voltage be at least 2.5 V below the power source. For example the +10
V range is only 2 volts under the carrier’s +12 V source and will cause possible
errors in the DACs operation. Therefore an external power source of +15 V is
required to ensure proper operation.
B.2.1 Avionics Signal Simulations
This application example provides the user with one of many possible configurations for
using the DAC128V as an analog output reference. Flight Simulators and Automated-
Test-Equipment (ATE) systems require the need for simulation of many analog signals
generated from the line-replaceable-units (LRUs) contained in most avionics navigation
suites. Most avionics signals are directly proportional to a unit of measure (i.e., nautical
miles per hour, feet per second squared, inches of mercury, etc.) via an analog voltage
representation.
One example would be a barometric altitude signal from an LRU that would be
represented by a 12-bit DAC with 10 feet of altitude per bit resolution. This would be
represented as 2 raised to the 12th power times 10, for a total of 40,960 feet of absolute
altitude. If the DAC128V were configured for 0 to +10 V outputs, the altitudes between 0
and 40,960 feet would equate linearly to the range of 0 to +10 volts (in 0.000244 volt
increments).
Another example would be a range or distance-to-go signal that would be represented by
a 12-bit DAC with 1 nautical-mile-per-bit resolution. This would be represented as 2
raised to the 12th power, for a total of 4096 nautical miles of absolute distance. Again
with the DAC128V configured for 0 to +10 V outputs the distance between 0 and 4096
nautical miles would equate linearly to 0 to +10 V (in 0.00244 V increments). Similarly
with the DAC128V configured for 0 to +5 V, a velocity or true-air-speed signal could
have a resolution of 0.1 miles-per-hour (mph) per bit (which equals 0.00122 V
increments), yielding 0 to 409.6 mph true-air-speed.
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