Email: aborsic@brookes.ac.uk
CompanyName: Oxford Brookes University
Country: UK
Abstract:
OXBACT 5 Data Acquisition System's software architecture
Andrea Borsic, Christopher N. McLeod, Xicai Yue
We present in this paper a brief
overview of the OXBACT V's software architecture. Given the
complexity of modern EIT data acquisition systems, we believe OXBACT V's novel
software
architecture to be of scientific interest.
A typical EIT DAS (Data Acquisition
System) is composed by a custom data acquisition
subsystem, which can range from a single PCB board to full rack mount system,
and by a host PC
that controls the process and logs the data. On simpler systems the controlling
software
resides entirely on the host PC side. On more sophisticated instruments, the
DAQ (Data
Acquisition) subsystem is based on a DSP or on a microcontroller and part of
the software will
reside on it. The development of this low level software is long and error prone,
debugging
tools are difficult to use and maintenance is hard.
In order to overcome the limitations
of the classic architecture we identified a new structure
that amongst other advantages offers a quicker development process, improved
development tools
and better maintenance cycle. We decided to base the custom DAQ subsisted on
a Pentium
compatible PC104 board. The presence of a ``traditional" processor in the
DAQ subsystem allows
running an embedded real--time OS on it. All the signal processing tasks previously
carried
out via DSPs can now be performed by the Pentium processor and be coded in higher
level
language for a much quicker development cycle. The presence of an OS and of
standardised
hardware components allows us to connect the DAQ subsystem to the data logging
PC via
traditional network solutions (Ethernet, Wireless Ethernet) and to develop all
the
communications tasks on top of the TCP/IP protocol. Several other details of
interest will be
presented, including the use of MATLAB for direct control of the instrument
and data
acquisition tasks.