Showing papers presented at "AUTOTESTCON in 2000"

A new bridging fault model for more accurate fault behavior

Abstract: We describe a new bridging fault model which more accurately simulates the behavior of bridging faults that have been observed as a result of manufacturing fabrication defects in tightly packed logic structures.

On-line built-in self-test for operational faults

Abstract: On-line testing is fast becoming a basic feature of digital systems, not only for critical applications, but also for highly-available applications. To achieve the goals of high error coverage and low error latency, advanced hardware features for testing and monitoring must be included. One such hardware feature is built-in self-test (BIST), a technique widely applied in manufacturing testing. We present a practical on-line periodic BIST method for the detection of operational faults in digital systems. The method applies a near-minimal deterministic test sequence periodically to the circuit under test (CUT) and checks the CUT responses to detect the existence of operational faults. To reduce the testing time, the test sequence may be partitioned into small sequences that are applied separately - this is especially useful for real-time digital systems. Several analytical and experimental results show that the proposed method is characterized by full error coverage, bounded error latency, moderate space and time redundancy.

The role of a signal interface in supporting instrument interchangeability

Abstract: This paper investigates the principles of instrument interchangeability in Automatic Test Systems by identifying the effects of instrument replacement and by analyzing the existing solutions for interchangeability problems. The "robust" instrument interchangeability provided by the IVI-MSS approach is presented in detail. The solution proposed in the paper consists of the standardization of a Signal Interface as semantic contents for IVI-MSS interfaces. Besides the inherent advantages of the IVI-MSS architecture, this approach provides portability of components among different testing environments. The functional requirements, integration issues and associated business model for the proposed solution are analyzed.

A non-intrusive estimation of the carrier frequency in GMSK signals

Abstract: The paper presents an efficient technique for evaluating the carrier frequency in GMSK communication systems. This technique operates in a non-intrusive way and is based on measurement of the frequency shift from the expected value. It utilizes the Learning Vector Quantisation neural network based demodulator for reconstructing the transmitted phase. From this and the received phase the mean value of the frequency shift is estimated. The technique does not require a high frequency sampling rate because the base-band signal is processed. Tests performed on experimental GSMK signals show that the technique is quite attractive and is also fast and more accurate compared to others.

IEEE 1232 and P1522 standards

Abstract: The 1232 family of standards were developed to provide standard exchange formats and software services for reasoning systems used in system test and diagnosis. The exchange formats and services am based on a model of information required to support test and diagnosis. The standards were developed by the Diagnostic and Maintenance Control (D&MC) subcommittee of IEEE SCC20. The current efforts by the D&MC are a combined standard made up of the 1232 family, and a standard on Testability and Diagnosability Metrics, P1522. The 1232 standards describe a neutral exchange format so one diagnostic reasoner can exchange model information with another diagnostic reasoner. In addition, software interfaces are defined whereby diagnostic tools can be developed to process the diagnostic information in a consistent and reliable way. The objective of the Testability and Diagnosability Metrics standard is to provide notionally correct and mathematically precise definitions of testability measures that may be used to either measure the testability characteristics of a system, or predict the testability of a system. The end purpose is to provide an unambiguous source for definitions of common and uncommon testability and diagnosability terms such that each individual encountering it can know precisely what that term means. This paper describes the 1232 and P1522 standards and details the recent changes in the Information models, restructured higher order services and simplified conformance requirements.

A decision support system for fuzzy scheduling of software projects

Abstract: In this study, a fuzzy project scheduling decision support system applied to a real world software development project is presented. The purpose of the project scheduling system is to allocate resources (engineers with different skill and experience levels) to activities with different complexity levels and uncertain durations. The activities are nonpreemptive in nature and there are no strict precedence relationships between them. The activity durations are modeled by fuzzy numbers as a function of the skill level of the resource allocated to that activity and the complexity level of the activity. Skill and complexity levels are also represented by fuzzy numbers. The objective of the scheduling of activities is the minimization of the project completion time. In scheduling three heuristic scheduling rules are utilized. These scheduling rules are presented with their applications on sample problems derived from a particular software development project. The decision support system carries the task of organizing the input data entry for scheduling the generation of the schedule, and the presentation of the results to the user.

Designing a parallel, distributed test system

Abstract: The increasing use of parallel architectures and networking technologies has enabled test systems to break free from their traditional structure. Today's systems run multiple parallel tasks, distribute testing among many computers, and publish live data through the Internet to achieve faster performance, better reliability, and increased connectivity with enterprise-wide systems. Specifically, software technologies and techniques are examined for developing and running parallel, distributed automated tests and distributing test data between applications or across the Internet. If used correctly, the result of these techniques is a higher performance, more robust test system. In addition, we examine technologies that make creating these parallel, distributed systems possible for not only the advanced test program developer, but also the novice user.

The problem with aviation COTS

Abstract: Commercial Off the Shelf (COTS) has become a byword for acquisition reform, but there are significant risks associated with the use of COTS products in military systems. These risks are especially acute for aviation systems. This paper explains how COTS can negatively affect military acquisitions and gives ideas on how to plan and resolve COTS caused problems.

Useful features of automated test systems in the R&D laboratory

Abstract: This paper lists, describes, and justifies features that a research and development engineer or technician would benefit from having in his or her automated test system Features are presented relating to data acquisition, stimulus, control, user interface design, configuring measurements, documentation, storage, analysis, and system integrity This paper can serve as a guide in designing features of a laboratory test system

Test engineering education: a guide to a successful curriculum

Abstract: An extensive curriculum in test engineering was presented to approximately 20 beginning and intermediate engineers with Bachelors and Masters degrees in Electrical and Electronics Engineering. Over a period of 33 weeks these engineers were taught the rigors of test engineering, including such subjects as Test Program Set (TPS) Development, ATLAS, Building an ATE, Instrumentation and ATE Architecture, the VXIbus, Software Test, Quality Assurance, Design for Testability, Built-In Self Test, Integrated Diagnostics and Artificial Intelligence in Test, Electromagnetic Compatibility (EMC), and nonmental Testing. Graduates immediately began to develop TPSs for F-16 Avionics circuit card assemblies. This work involved re-hosting many of the TPSs. The performance of these graduates at their job is used as one of the evaluating factor for the success of the curriculum. Comments from instructors are also included. Finally a cost benefit analysis is given to evaluate the cost-effectiveness of TPS training.

A performance tracking methodology and decision support model

Abstract: This paper presents a methodology to detect performance degradation with a certain degree of confidence, and a decision support model to help engineers and technicians to solve ongoing diagnostic and repair problems. The method is capable of detecting changes in performance trends when data captured at different times or ages during the system's active life, is compared to estimated performance limits. This paper applies the method to the specific case of aircraft avionic systems and their associated support equipment. The methodology is currently being developed and applied to existing aircraft avionic equipment and maintenance processes. The methodology explores the ability of statistical control process (SPC) applications and expert systems (ES) based technologies to develop trend analyses data and provide performance degradation information to maintenance engineers, technicians, and managers. The paper addresses specific data capture and component identification problems encountered in actual test data, anal discusses automated solutions for these problems. A complete architecture is presented displaying the data capture process, data storage, statistical and expert system processing, and output information display. The solution includes the specific technology used to implement the process and output information samples based on actual test data.

The state of interchangeability in ATE

Abstract: The Interchangeable Virtual Instrument (IVI) Foundation formed in August of 1998 to address the challenge of instrument interchangeability in the test and measurement industry. Since its inception, the NI Foundation has engaged in vigorous standardization activities along several different though coherent, axes. Instrument class specifications are continuously under development for some of the most pervasive types of instruments. Architectural standards establishing IVI conformance criteria will broaden the capability of vendors, end-users, and system integrators to innovate while simultaneously allowing them to integrate into a heterogeneous IVI-based system. IVI Measurement Stimulus Subsystems (NI-MSS) standards under development offer the promise of a higher level of interchangeability than instrument-centric standards can offer. Shared NI infrastructure components will ensure interoperability in IVI systems by providing a common model for services such as configuration, installation, resource sharing, event notification and management and component instantiation. In addition, the Foundation has embraced COM technology as a powerful means for delivering interchangeable ATE software services.

Information-based standards and diagnostic component technology

Abstract: Software development methods have evolved over the years from structured design of procedural code, to object oriented design, to component-based design. Recent requirements by industry and government have resulted in the development of interface specifications and standards designed to facilitate acquisition of large systems based on the concepts of component technology. In this paper, we discuss the development of information-based standards for diagnostic information and diagnostic reasoning intended to provide the definition of diagnostic components within a larger test or health management environment.

Networked diagnostic communications in avionics support

Abstract: Accurate diagnosis of avionics failures is being complicated by increasing complexity in the prime system, combined with COTS maintenance documentation and software that tend to be less comprehensive and more difficult to keep current, when compared to that of specially developed systems. These complications, and their potentially negative impact on diagnostic effectiveness and mission readiness, can be alleviated by using modern network technology to provide an "expert presence" at the local maintenance site, even though the expertise to solve a given diagnostic problem may be distributed among several remote locations. Expert presence includes, but is not limited to, video conferencing. Uploading of cockpit video, as well as special documentation and software downloads may also be employed.

Test vector compression via statistical coding and dynamic compaction

Abstract: This paper addresses the problem of increasingly longer test times and greater test data storage requirements for integrated circuits. A new compression/decompression technique is proposed for reducing the amount of data that must be stored on the tester and transferred to the chip. This technique uses static and dynamic compaction algorithms in conjunction with statistical coding to encode test vectors provided by circuit vendors. The decoding process is performed in hardware by a small amount of on-chip circuitry. Taken together, this compression/decompression algorithm results in both lowered tester storage requirements and reduced test times.

JET Engine Test Strategy-program overview and objectives

Abstract: JET Engine Test Strategy (JETS) is an innovative program for improving existing Air Force jet engine test cells. This paper describes the key elements of the JETS and discusses the phased approach for its implementation and realization of the benefits. The proposed system components for implementation of JETS benefits are contained in the Automated Jet Engine Test System (AJETS), which includes the instrumentation system, throttle control, engine-specific test programs, and a network. Charts and photos am used to illustrate current and projected features and benefits of JETS.

Common test architecture development for munitions level best platforms

Abstract: A need for a common munitions test architecture emerged with the development of sophisticated weapon systems and the need to support those weapon systems from the production floor in the factory through night test. With the cost of test soaring, more and more money was being spent on special test equipment and less and less on the procurement of weapon systems. A common architecture for hardware and software reduces the high cost of Automated Test Equipment (ATE). Raytheon Company first developed this architecture as part of the development of the Guided Weapons Test Station (GWTS). The GWTS is a standard family of ATE which meets the defense industry's need for a common munitions tester at the ail-up-round (AUR) and guidance section levels. The GWTS is comprised primarily of Commercial Off The Shelf (COTS) instrumentation and software. The need for a more robust architecture on munitions level platforms arises with the continued development of test instrumentation and software, and the understanding of the automated test environment, Raytheon has continued to evolve this architecture for use on their component and intermediate level Standard Test Equipment Platforms (STEPs) and in the future hopes to incorporate these changes into their next generation of munitions level test platforms. A candidate for this next generation platform would be the development of a Common Munition STEP (CMSTEP) that could be utilized in conjunction with future developed Operational Test Program Sets (OTPSs) to provide munitions level test capability.

Case study: modular ATE system design

Abstract: Faced with ever-increasing constraints of budget reductions and fight schedules, test engineers are looking for faster, more cost-efficient ways to get automatic test equipment (ATE) systems up and running. This case study examines a process known as Freedom/sup TM/ Series, developed by Racal Instruments, illustrating how the principles of design reuse and automation, applied to ATE systems, can dramatically reduce non-recurring engineering costs and accelerate schedules. Freedom Series is a modular approach to ATE system design. It exploits design reuse by standardizing components such as test instruments, interface cables, software drivers, and documentation. In addition, Freedom Series provides software tools that automate many non-recurring engineering tasks. The combination of modularity, reuse, and automation accelerates the system integration process and, in many cases, virtually eliminates non-recurring engineering costs.

New support perspectives and contracting methodologies for the consolidated automated support system (CASS)

Abstract: Development of novel and innovative ATE support concepts is evidenced by the Consolidated Automated Support System (CASS) Maintenance Support Pool (MSP), Direct Vendor Delivery (DVD), and Consolidated Support Pool (CSP) programs These initiatives have simultaneously reduced total ownership costs to the Navy, improved operational readiness, and provided sufficient return on investment for the contractor The migration of MSP to DVD to CSP has allowed the contractor to compile data required for determining trends, usage, and failure data An important factor in ensuring success is the long-term commitment by the Navy and the contractor This paper outlines support business process re-engineering required to affect cultural change

Model-based diagnosis support for satellite-based instruments

Abstract: An accurate understanding of the current health status is an essential part of the central of highly autonomous systems. This health information is delivered by what is normally known as diagnosis systems. Due to the complexity of systems, the construction of diagnosis systems is hard. The so-called model-based approach simplifies this task as only a behavioral specification of each of the system's components is needed. In this paper we describe UpTime, a tool supporting the construction of component-based models of device behavior and the generation of diagnostic algorithms. The main features of UpTime are: (i) declarative and component-based description of system behavior to ease the modeling phase; (ii) support for automatic hierarchical abstraction generation; and (iii) generation of test vectors that take safety conditions into account.

Logistics Control and Information Support (LOCIS)

Abstract: The downsizing of the U.S. armed forces, the reduced funding and sparing for parts, and the increased number of simultaneous threat engagements have led to a requirement for even greater control over available resources at the wing level. Current management information systems for wing-level logistics are slow and manpower intensive, often requiring a team of specialists to manually interpret logistics data from multiple, uncorrelated locations, During 1995-1997 a feasibility study, requirements analysis and concept demonstration projects were led by the Air Force Research Lab Human Effectiveness Directorate (AFRL/HESR) to determine the need for a Research and Development (R&D) program that would investigate better ways to improve the timeliness and understandability of logistics information. Based on the success of these early projects and the identified need for a wing-level command and control logistics support fool, the current 42 month Logistics Control and Information Support (LOCIS) program was born. A long-term, integrated solution requires a new look at the process, information, and emerging technologies. LOCIS is the beginning of this process as it supports the fusion of information, logistics, and advanced techniques to provide rapid crisis response, to track and shift assets (even while en route), and deliver tailored information directly to the strategic command managers. This paper describes the process LOCIS will undergo over the next 42 months and the benefits expected from the LOCIS wing-level command and control logistics capabilities.

Prognostics Framework-UPDATE II

Abstract: The "Prognostics Framework" is a generic software tool set with an open architecture capability to integrate various prognostic mechanisms, and to provide operational and logistic decision-making information. The Prognostics Framework is a horizontal technology and is user-tailorable to apply to any new or existing system. The overall approach will save time and money and is the fastest way for individual projects to converge on prognostics capabilities through manageable information for the system operators, the maintenance crew, and logistics planners. The Prognostic Framework, a system-level prognostic manager, ties-in to logistics infrastructure (e.g.: IETM, logistics planning, mission planning, statistical tools, spare parts provisioning). Prognostics Framework is integrated with embedded diagnostics to provide a total "Health Management" capability. This paper defines the Prognostics Framework architecture, design approach, and interface capabilities.

Distributed and concurrent test environments on popular COTS platforms

Abstract: Today's automatic test system implementations likely require some aspect of real-time performance, concurrency, and network connectivity. Users expect responsive, efficient operation, both at the local operator interface as well as remotely via a LAN or the Internet. Distributed, concurrent COTS software systems, such as Sun Microsystem's Java and Microsoft's Win32 are a natural fit to these requirements. Based on real-world experience developing distributed, concurrent test systems, this paper reviews some of the unexpected obstacles implementers might encounter. We discuss the creation of threads, thread scheduling, and the use of thread synchronization constructs. We compare these mechanisms to those available in IEEE Standard ATLAS and test-specific programming frameworks.

Next generation functional test program development system

Abstract: While superior-quality functional board test has been a goal for most high reliability electronics manufacturers, the time and effort for generating such test programs using today's tools and processes makes this difficult to achieve in a cost effective manner. This paper will introduce a revolutionary approach to functional board test program development that combines the comprehensiveness of software-based simulation with the speed and simplicity of hardware emulation. The result is a functional Test Program Set development system that can produce high fault coverage, diagnostic test programs in a fraction of the time it takes using traditional techniques, and at a lower unit cost. In this paper we will first provide a brief background on the strengths and weaknesses of current software and hardware TPS development techniques-simulation hot mock-up. Next, the new approach is described in detail and contrasted against the existing techniques. Finally, we present actual experience to date using a prototyped system.

Writing test modules using standard interfaces and languages

Abstract: The focus of today's test system programmer is code reusability through common test modules. To achieve the greatest reusability these modules should be written using standard interfaces, such as DLLs and ActiveX automation servers. By using these standard interfaces inside an enterprise code modules can be used across development teams and in different projects. We discuss specifically: explaining the pros and cons of standard DLLs versus ActiveX/COM automation servers; programming these interfaces into test modules using standard programming languages, such as National Instruments LabWindows/CVI and Microsoft Visual Basic and Visual C++; integrating these interfaces into projects and test executives.

EAF challenge to ATE

Abstract: The Expeditionary Aerospace Force (EAF) Concept presents a severe challenge to the test community. ATE Systems included in the support structure of this new concept must exhibit characteristics seldom if ever seen before. This paper will attempt to predict what characteristics such a forward-looking ATE system must possess It will focus on the critical aspects of ATE architecture and the importance of such an architecture being truly open in every sense of the word. The importance of a COTS approach utilizing this truly open architecture will be stressed since experience proves this leads to the lowest possible cost and size plus freedom from tester obsolescence. Other important issues to be addressed include transportability, system throughput and overall risk. The positive effects of horizontal and vertical test integration are discussed and the virtual elimination of the cannot duplicate, retest OK problem highlighted. Other accrued benefits to be covered include commonality of operator training, commonality of test programming language, common spare parts pools, self-test and calibration similarity, ease of test data transfer and reduction, commonality, of documentation, elimination of tester NRE and a dramatic decrease in TPS development costs. In addition, the requirements and characteristics relative to specific hardware and software items are addressed including the ATE operating software system, low and high frequency switching, system timing, digital and analog subsystems, RF subsystems, bus structure, etc. The roles which virtual instrumentation and paperless documentation should play are also included.

JET Engine Test Strategy-system design

Abstract: JET Engine Test Strategy (JETS) is an innovative program for improving existing Air Force jet engine test cells. Automated Jet Engine Test System (AJETS) is the hardware and software installed in test cells. JETS encompasses AJETS, the network, and ancillary equipment initiatives. This paper describes the design features of AJETS and the network that will allow improved engine test data, diagnostics, and prognostics. These features are being implemented to reduce engine support costs and meet the requirements for cradle-to-grave maintenance. The design features of AJETS are being evaluated and advanced in TF39 test cell installations at Travis AFB and Dover AFB.

A method for testing partially programmable logic arrays in CPLDs

Abstract: We describe a method for developing a minimal set of four test configurations with associated minimum sets of test patterns that completely tests reprogrammable Programmable Logic Arrays (PLAs) with partially programmable OR-planes typically found in Complex Programmable Logic Devices (CPLDs). The resultant set of test configurations and vectors detect all single and multiple stuck-at faults (including line and transistor faults) as well as all bridging faults without requiring hardware modifications in the PLA. Previous methods for testing reprogrammable PLAs have dealt only with fully programmable OR-planes.

A flexible automatic test system for turbine machinery

Abstract: The objective of this paper is to discuss the general development of a Flexible Automatic Test System For Turbine Machinery (FATSFTM) In order to meet the test needs of a large and diverse community of turbine machinery, the automatic test system should have a contemporary windows interface, have graphical interaction and be easily configured to include the functions required by current and emerging test demands The design and implementation of such a test system is approached from an object-oriented software engineering point-of-view for ease of extension, expansion and maintenance Practical application has proved the validity and effect of the implemented automatic test system in helping turbine developers improve the performance of turbine machinery

Automatic test equipment (ATE) on a network (securing access to equipment and data)

Abstract: Integrating ATE into a network allows faster software upgrades to operating systems and Test Program Sets (TPS) for ATE systems. Upgrades to operating systems can be made to several ATE stations at one time from one computer TPS can be stored onto a sewer that can be shared by all the ATE stations. This allows upgrades to TPS at one location and not across ad of the ATE stations. Test data, calibration data, and other files on ATE stations can be monitored for troubleshooting of the system. Having ATE stations on a network, however, could pose some security risks if security is not addressed during the integration design process. The designer must have intimate knowledge of the network architecture and network security products to secure access to the equipment and protect the information flow to and from the ATE. The OSI model can assist the designer in understanding the network architecture and understanding at which level of the architecture the different security products can be applied to meet the security goals. At the network architectural level the ATE integrator becomes familiar with routers, switches, hubs, and methods of controlling traffic on a network. At the secured level the ATE integrator addresses which level of the OSI model to secure. Security can be applied at the top of the model at the application layer with products like Public Key Infrastructure (PKI), at the middle of the model at the session layer with products like firewalls, or at the bottom of the model at the physical layer with cryptographic devices. The last item that the designer needs to include during the integration of ATE onto a network is the network administrators.