Range
Safety
AlliedSignal Technical Services Corporation
deployed five Visual Test Systems to meet their need
for flexible and reliable telemetry processing capabilities
to support range safety requirements for the Shuttle.
The systems receive, process, extract, multiplex, and
retransmit shuttle range safety data. Each receives
one PCM wavetrain at a time*, decommutates each wavetrain,
extracts identified range safety parameters, creates
a forward link based on the extracted range safety measurements
from all four sources in a predetermined hierarchy,
and transmits the range safety wavetrains to a number
of remote stations over an RS-422 network interface.
* Each wavetrain includes two embedded PCM wavetrains
with voice and data.
Flight
Test System Checkout
Sikorsky is relying on a multiprocessor
VTS system on the flight line to check out entire airborne
telemetry systems prior to flight test. The VTS verifies
sensor calibration, data acquisition, PCM encoding,
and video transmission subsystems.
Sikorsky’s VTS supports two independent
streams and provides PCM receiving, bit synchronization,
decommutation, processing, archiving, and quick-look
display capabilities. When connected to a network port,
the VTS transfers real-time or archived data to a heritage
ground station, freeing the range ground station for
other flight tests. In the future, the system can be
expanded to simultaneously acquire data directly from
MIL-STD-1553 and ARINC 429 avionics buses.
Balloon Flight
Four VTS systems are being used at Holloman
AFB in New Mexico and in various worldwide locations
for everything from balloon control checkout to flight
data analysis. During checkout, the VTS’ integral simulator
helps to verify that each bit in the defined stream
is functional. The instrumentation system is then moved
to the flight line, where the entire data acquisition
system is checked — from sensor integration to processing
to data archiving. During flight test scenarios, multiple
systems can continuously monitor and capture data as
required. Real-time and archived data is sent to scientific
teams for analysis, often providing unprecedented insight
into atmospheric phenomenon, or proving the equipment
or experiment on board the payload.
Avionics
Bus Test
At numerous locations worldwide, the
VTS is being used as a replacement for L-3’s venerable
Serial Bus Analyzer (SBA) MIL-STD-1553 bus tester. The
VTS allows avionics engineers to test, debug, and verify
MIL-STD-1553 subsystems on the “hot bench” or in the
vehicle to ensure that new versions of hardware are
compatible with embedded software. Additionally — using
only the VTS — engineers can record all data to disk
(limited only by disk capacity) to quickly monitor 1553
traffic with the “Activity” page and to perform BC and
RT simulations. The system’s ability to parameterize
MIL-STD-1553 data words and display data alongside PCM,
analog, and other inputs, makes the VTS a powerful tool
for throughput evaluation and complete system testing.