Recording Digital Data can be achieved by a number of different means. Most
often, the data is recorded onto some form of tape based media such as DAT or
AIT tapes, although Hard Disk and Solid State drives are fast becoming the norm. The type of data can be from any source that provides a constant or
variable data stream such as PCM, ARINC 429,
MIL-STD-1553, Voice data, Aeronautical signals etc.
A Data Recorder uses Signal Acquisition circuits (Data Acquisition System
DAS) to accept the incoming data
and make it available to be recorded onto the media. Sometimes the data requires
conditioning to assist in the correct recording of the data. Timing accuracy is
achieved by inbuilt clocks which can be synchronised to an
IRIG clock signal from an external
IRIG time generator.
Once recorded the data can be played back either in real time or at an
accelerated rate for analysis by computer software.
A data acquisition system is a device designed to measure and log some
parameters. The purpose of the data acquisition system is generally the analysis
of the logged data and the improvement of the object of measurements. The data
acquisition system is normally electronics based, and it is made of hardware and
software. The hardware part is made of sensors, cables and electronics
components (among which memory is where information are stored). The software
part is made of the data acquisition logic and the analysis software (and some
other utilities that can be used to configure the logic or to move data from
data acquisition memory to a laptop or to a mainframe computer). An example:
Data logging, carried out by a data acquisition system (DAS), can be used to
measure parameters such as temperature and humidity in storage facilities with
perishable products; the measurement data is then stored for analysis to improve
quality assurance. Another example: a data acquisition system can be placed on a
race car to measure RPM and vehicle speed to analyze car's behaviour once it's
back to pits and improve the car setup.
Data logging and Recording systems
Data logging and Recording systems consist of four elements:
1. Measuring output (sensors around the vehicle)
2. Recording output signals (logger unit)
3. Uploading/accessing recorded data (telemetry)
4. Analysis of recorded data. (DAS software)
The 4 elements above have specific requirements which need to physically
present and included in the design process. Sensors to measure selected
parameters must meet certain specifications, and the routing of the sensor
cables ensures they will not suffer from electromagnetic interference from other
electronic systems. The DAS unit (including memory) and the link from the DAS
unit to the operating platform to upload the acquired data via a hardwire cable
or telemetry also must conform to requirements.
The Heim Systems data recorders supplied by
Photo-Sonics International are airborne qualified and tested for use in Aircraft
Test and Development. We also supply Ground Station systems for monitoring
Telemetry Data and replay of the data.
Recording media has moved on since tape based equipment. We now supply
recorders which use a variety of media, including Hard Disks and Solid State
Systems.
