8 research outputs found
An Approach to remote process monitoring and control
The purpose of this thesis is to present an approach to remote monitoring and operation of distributed real time process control systems. Conventional monitoring of process control systems currently requires a great deal of close supervision from trained personnel located on-site. In many cases, researchers, developers or maintenance personnel cannot be at every location where such a system is installed. Currently, a standardized architecture for remote access to such systems is not available. In addition, most of these systems are very expensive and under-utilized. Researchers would benefit by having access to different parts of a system concurrently The benefits of a layered architecture for remote process monitoring and control will be analyzed through the use of a demonstration system that was realized to examine the real time performance of the interconnection mechanisms between the process controller(s) and the system monitoring interfaces. Low level, real-time process control is achieved by using specialized networking schemes called fieldbusses to interconnect all control devices. In this system, fieldbus controllers will also assume the role of servers connected to the Internet, in order to make device information available to any local or remote clients. In the proposed architecture, remote clients are user interfaces, implemented as JAVA applets, which can be accessed with a web browser. The proposed system architecture allows for client interfaces to gain remote access to various types of fieldbusses transparently
Wearable biosensing: signal processing and communication architectures issues, Journal of Telecommunications and Information Technology, 2005, nr 4
Long-term monitoring of human vital signs is becoming one of the most important fields of research of biomedical engineering. In order to achieve weeks to months of monitoring, new strategies for sensing, conditioning, processing and communication have to be developed. Several strategies are emerging and show different possible architectures. This paper essentially focuses on issues in wearable biosignal processing and communication architecture currently running at the Swiss Center for Electronics andMicrotechnology (CSEM) in the framework of several European projects
A conformance test framework for the DeviceNet fieldbus
The DeviceNet fieldbus technology is introduced and discussed. DeviceNet is an open standard fieldbus which uses the proven Controller Area Network technology. As an open standard fieldbus, the device conformance is extremely important to ensure smooth operation. The error management in DeviceNet protocol is highlighted and an error injection technique is devised to test the implementation under test for the correct error-recovery conformance. The designed Error Frame Generator prototype allows the error management and recovery of DeviceNet implementations to be conformance tested. The Error Frame Generator can also be used in other Controller Area Network based protocols.
In addition, an automated Conformance Test Engine framework has been defined for realising the conformance testing of DeviceNet implementations. Automated conformance test is used to achieve consistent and reliable test results, apart from the benefits in time and personnel savings. This involves the investigations and feasibility studies in adapting the ISO 9646 conformance test standards for use in DeviceNet fieldbus.
The Unique Input/Output sequences method is used for the generation of DeviceNet conformance tests. The Unique Input/Output method does not require a fully specified protocol specification and gives shorter test sequences, since only specific state information is needed. As conformance testing addresses only the protocol verification, it is foreseen that formal method validation of the DeviceNet protocol must be performed at some stage to validate the DeviceNet specification
A new approach to the development and maintenance of industrial sequence logic
This thesis is concerned with sequence logic as found in industrial control systems, with
the focus being on process and manufacturing control systems. At its core is the assertion
that there is a need for a better approach to the development of industrial sequence logic
to satisfy the life-cycle requirements, and that many of the ingredients required to deliver
such an approach are now available.
The needs are discussed by considering the business case for automation and
deficiencies with traditional approaches. A set of requirements is then derived for an
integrated development environment to address the business needs throughout the
control system life-cycle.
The strengths and weaknesses of relevant control system technology and standards are
reviewed and their bias towards implementation described. Mathematical models,
graphical methods and software tools are then assessed with respect to the requirements
for an integrated development environment.
A solution to the requirements, called Synect is then introduced. Synect combines a
methodology using familiar graphical notations with Petri net modelling supported by a set
of software tools. Its key features are justified with reference to the requirements. A set of
case studies forms the basis of an evaluation against business needs by comparing the
Synect methodology with current approaches. The industrial relevance and exploitation
are then briefly described.
The thesis ends with a review of the key conclusions along with contributions to
knowledge and suggestions for further research