Transputer-based Systems Research Articles

Trapper: A graphical programming environment for parallel systems

We present a graphical programming environment for parallel systems called TRAPPER ™. TRAPPER supports the development of industrial applications which require high computing power. The programming environment is based on the programming model of communicating sequential processes. TRAPPER contains tools for the design, mapping, visualization and optimization of parallel systems. The Designtool supports a hybrid program development, where the parallel process structure is described using a graphical representation and the sequential behavior is described using textual representations. The configuration of the target hardware and the mapping of the application onto the configured hardware is supported by the Configtool. During run-time, the monitoring system records software events like interprocess communication and measures the computation and communication loads of the underlying hardware. The run-time behavior of the software is animated by the Vistool, the load behavior of the hardware is displayed by the Perftool. The first target systems are transputer-based systems as well as workstation clusters and parallel supercomputers with the standard interfaces PVM, PARMACS or MPI.

Transputer-based multi-agent monitoring system in NC

This paper describes the design and implementation of a system base software platform for transputer-based systems that is being used for experimentation in prognostic and monitoring of CNC machines using the multi-agent paradigm. After an introduction to the application domain, the basic requirements and the structure of a suitable base software environment are described, emphasizing the heterogeneity issue. The logical model of the implemented monitoring and prognostic system as well as the integrating agents and machining model are presented and discussed.

Developing transputer-based systems using HOOD and Parallel C

Parallel C is one of a number of high level languages now being used to program the transputer as well as Occam. These languages have been used successfully to program the transputer in a variety of application areas. Large-scale software systems should be specified at higher levels of abstraction during the early stages of system development. Design methods promote a systematic and methodical approach to the development of software. This paper describes the use of a particular method, HOOD, for the design of transputer-based systems. It has been used with Ada and C to program other architectures. Both HOOD and Parallel C support concurrency and are based on the synchronous approach to inter-process communication. Therefore, a consistent approach to concurrency and communication is adopted at the design and implementation phases. The paper outlines the transformation from HOOD to Parallel C and the implementation of HOOD's design features. The overall approach is best used with coarse-grain client-server applications, though some optimization during implementation is still necessary.

SYNC_WAVE: a high accuracy and low overhead algorithm for clock, synchronization in transputer networks

This paper addresses the implementation of global time in transputer systems by software synchronization of local processor timers. After an introduction on the synchronization problem, SYNC_WAVE, a synchronization algorithm for multicomputer architectures, is briefly described. The rest of the paper gives details of an existing implementation of SYNC_WAVE for transputer-based systems. Most of the devised code is presented and commented on, showing the methods used to improve synchronization accuracy and to read the global clock from within a user process. The performance results obtained are shown, and the usefulness and portability of the proposed code are discussed.

The design of time-critical conversations

The problems associated with ensuring a correct and timely response are particularly acute in computing systems which must satisfy critical timing requirements. Faults must be recognised promptly and the overheads of state restoration and retries must be tightly controlled so that real-world time constraints are not violated. This paper describes how a form of rate-monotonic scheduling could be used to incorporate deadline mechanisms into transputer-based systems in order to provide timely fault-tolerance through conversations.

Allocation of precedence-constrained tasks to parallel processors for optimal execution

The present work describes two methods for allocating m precedence-constrained tasks to n identical processors for optimal execution, uniform static load balancing and minimum interprocessor communication. The comparative studies made between two methods, the Simulated Annealing and a well-chosen Heuristic, indicate the suitability of the latter for complex precedence graphs. Examples from Matrix algebra have been chosen for the experiments. The resulting methods can be readily applied to optimize performance of practical problems on distributed memory parallel processor systems such as transputer-based systems.

Debugging and monitoring highly parallel systems with grip

This paper reports an investigation to build a tool for the debugging and monitoring of highly parallel systems. The investigation is based on the principle of folding/unfolding graphical user interface and materialised in the design of GRIP. Initially we based our investigation on transputer-based systems but will be extended in a later stage to incorporate other non-transputer-based parallel systems.

Programmable interface for Transputer-based data acquisition and control

A circuit is described which can interface instrumentation with cost-effective Transputer-based systems. Four control lines, 12-bit A/D conversion at programmable sample time, and accessibility to concurrent computing are provided.

Analogue I/O strategies for transputers

With the advent of increasingly sophisticated multivariable systems for the control of advanced aircraft designs 1,2 has come the demand for further improvements in processing capacity and speed. These are becoming increasingly difficult to satisfy using conventional, sequential microprocessor-based systems, but the use of parallel processing concepts exemplified by the Inmos transputer will realize the required performance. To achieve this the transputer must be provided with a large bandwidth, high-performance data acquisition system. The paper surveys several practical strategies which provide the Inmos transputer development system (TDS) with a flexible analogue data acquisition capability. Three techniques have been implemented in Salford University's Department of Aeronautical and Mechanical Engineering, two of which are examined in detail. The interfacing methods identified may be categorized as: Host-based systems — (a) software interface and (b) combined software and hardware interface; External bus-based systems — (a) transputer(s) on the bus and (b) bus emulation; and Wholely transputer-based systems — (a) link-compatible autonomous devices and (b) memory mapped devices. Each type is discussed briefly and examples of combined software and hardware interface systems, and memory mapped devices are presented as case studies.