An application of an ethernet based protocol for communication and control in automated manufacturing

The exchange of information in the industrial environment is essential in order to achieve complete integration and control of manufacturing processes. At present the majority of devices present in the shop floor environment are still used as stand alone machines. They do not take advantage of the possibilities offered by a communication link to improve the manufacturing process. The subject of this research has been centered on the development of a simple, flexible and inexpensive support system for communication and control of manufacturing processes. As a result, a system with these features has been proposed and implemented on a simulated workcell. The area footwear manufacturing was chosen for modelling the workcell. The components of the manufacturing support system were developed using an object oriented approach which allowed modularity and software reuse. In order to achieve communication between the components, a communication protocol was developed following the process defined in the rapid protocol implementation framework. Ethernet was selected for implementing the lower levels of the protocol. Java, a new object oriented programming language used for the implementation of the system, showed that it could became a promising language for the implementation of manufacturing applications. In particular the platform independence feature of the language allows the immediate porting of applications to systems with different features. The manufacturing cell simulation had shown that the times associated with the manufacturing support system operations are compatible for its use in applications where the response times are in the order of one second

A Performance Comparison of UNIX Operating Systems on the Pentium

This paper evaluates the performance of three popular versions of the UNIX operating system on the x86 architecture: Linux, FreeBSD, and Solaris. We evaluate the systems using freely available micro- and application benchmarks to characterize the behavior of their operating system services. We evaluate the currently available major releases of the systems “asis,” without any performance tuning. Our results show that the x86 operating systems and system libraries we tested fail to deliver the Pentium’s full memory write performance to applications. On small-file workloads, Linux is an order of magnitude faster than the other systems. On networking software, FreeBSD provides two to three times higher bandwidth than Linux. In general, Solaris performance usually lies between that of the other two systems. Although each operating system out-performs the others in some area, we conclude that no one system offers clearly better overall performance. Other factors, such as extra features, ease of installation, or freely available source code, are more convincing reasons for choosing a particular system. 1

M.: A Performance Comparison of UNIX Operating Systems on the Pentium

Abstract This paper evaluates the performance of three popular versions of the UNIX operating system on the x86 architecture: Linux, FreeBSD, and Solaris. We evaluate the systems using freely available micro-and application benchmarks to characterize the behavior of their operating system services. We evaluate the currently available major releases of the systems "asis," without any performance tuning. Our results show that the x86 operating systems and system libraries we tested fail to deliver the Pentium's full memory write performance to applications. On small-file workloads, Linux is an order of magnitude faster than the other systems. On networking software, FreeBSD provides two to three times higher bandwidth than Linux. In general, Solaris performance usually lies between that of the other two systems. Although each operating system out-performs the others in some area, we conclude that no one system offers clearly better overall performance. Other factors, such as extra features, ease of installation, or freely available source code, are more convincing reasons for choosing a particular system