Abstract This thesis studies the methods to test mixed-signal devices and circuits on board and system level with embedded test instrumentation. The study is divided in three continuous sections, development of embedded test methods for discrete components, integration of test instruments on board level and development of test and health monitoring strategy for large scale system. The developed embedded test methods for mixed signal circuitry on board level are based on the standard for mixed signal test bus IEEE 1149.4. The standardized embedded test infrastructure is utilized for testing discrete components with emphasis on testing active components as diodes and transistors. The developed embedded tests are evaluated with PCOLA/SOQ method for manufacturing testing and also the usability of the tests is discussed. A solution for embedded mixed-signal test controller is presented with discussion of test communication and the possibilities of implementing embedded test control. The target in the development of the test control is to enable launch mixed signal tests on device remotely. The test controller is IEEE 1149.4 compatible and can generate and measure analog test signals while controlling boundary-scan enabled devices. The final section of the thesis focuses on an embedded test solution for aerospace bus system (MIL-STD-1553). Current solutions are based on testing the bus system during maintenance on ground. The developed test and monitoring method allows on-line monitoring of the bus to detect and locate possible defects which only occur during use of the aeroplane. / Tiivistelmä Väitöstyössä tutkittiin sekasignaalilaitteiden ja -piirien testausmenetelmiä levy- ja järjestelmätasolla hyödyntäen sulautettuja testilaitteita. Työ jakaantuu kolmeen osaan; sulautettujen testausmenetelmien kehitys diskreeteille komponenteille, testi-instrumenttien integrointi piirilevytasolle sekä testaus- ja kunnonmonitorointimenetelmän kehitys laajemmalle järjestelmälle. Sulautettujen testimenetelmien kehitys sekasignaalipiireille piirilevytasolla perustuu sekasignaalitestiväylän standardiin IEEE 1149.4. Standardoitua sulautettua testi-infrastruktuuria käytettiin diskreettien komponenttien testaukseen painottuen aktiivikomponentteihin, kuten diodeihin ja transistoreihin. Kehitetyt sulautetut testit on arvioitu PCOLA/SOQ menetelmällä, jota hyödynnetään tuotantotestauksen testikattavuuden arvioinnissa. Lisäksi testimenetelmien käytettävyyttä arvioitiin. Sulautettu sekasignaalilaitteiden testikontrollerin tavoite on käynnistää ja suorittaa sekasignaalitestejä laitteessa etäältä. Kehitetty testikontrolleri on IEEE 1149.4 yhteensopiva ja voi generoida ja mitata analogista testisignaalia sekä samanaikaisesti ohjata testiväylää. Lisäksi etätestauksen mahdollistavasta testikommunikaatiomenetelmiä arvioitiin kuten myös erilaisia toteutustasoja sulautetuille testimenetelmille. Laajemman järjestelmän kehityksessä tutkittiin sulautettua testausratkaisua lentokoneen väyläjärjestelmälle, joka perustuu standardiin MIL-STD-1553B. Nykyiset menetelmät perustuvat väyläjärjestelmän testaukseen huollon yhteydessä, mutta osa virheistä ilmenee vain käytön aikana. Kehitetty testaus- ja monitorointimenetelmä mahdollistaa käytönaikaisen jatkuvan virheiden monitoroinnin sekä niiden paikantamisen lennon aikana.

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / The MARS-II digital recorder is one of the new technologies that will eventually replace the labor intensive and hardware dependent methods associated with traditional analog-based telemetry ground systems. The Standardized MARS-II Analysis and Reduction Tool (SMART) is one of the first software systems developed to take advantage of this new digital recording capability. It processes pulse code modulated (PCM) encoded data and MIL-STD-1553B message traffic, outputting time-tagged PCM frames or 1553 messages to file. The goal of this software is to provide a portable application that utilizes state-ofhe-art, general purpose hardware for rapid telemetry data processing to meet the needs of operational users, telemetry engineers, and data analysts. To satisfy these goals, the software was developed using the C language with VMS and OSF operating systems as the initially targeted platforms. In addition, an X Window System/Motif graphical user interface supporting three tiers of user interaction (operator, telemetry engineer, and telemetry analyst) was layered onto the decommutator functions.

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The Data Acquisition, Analysis, and Simulation System (DAAS) is a computer system designed to allow data sources on spacecraft in the Flight System Testbed (FST) to be monitored, analyzed, and simulated. This system will be used primarily by personnel in the Flight System Testbed, flight project designers, and test engineers to investigate new technology that may prove useful across many flight projects. Furthermore, it will be used to test various spacecraft design possibilities during prototyping. The basic capabilities of the DAAS involve unobtrusively monitoring various information sources on a developing spacecraft. This system also provides the capability to generate simulated data in appropriate formats at a given data rate, and to inject this data onto the communication line or bus, using the necessary communication protocol. The DAAS involves Serial RS232/RS422, Ethernet, and MIL-STD-1553 communication protocols, as well as LabVIEW software, VME hardware, and SunOS/UNIX operating systems.

This thesis describes distributed simulation of MIL-STD-1553B Serial Data Bus interface and protocol based on the Data Distribution Service (DDS) middleware standard. The data bus connects avionics system components and transports information among them in an aircraft. It is important for system designers to be able to evaluate and verify their component interfaces at the design phase. The 1553 serial data bus requires specialized hardware and wiring to operate, thus it is expensive and complex to verify component interfaces. Therefore modeling the bus on commonly available hardware and networking infrastructure is desirable for evaluation and verification of component interfaces. The DDS middleware provides publish-subscribe based communications with a number of QoS (Quality Of Service) attributes. DDS makes it easy to implement distributed systems by providing an abstraction layer over the networking interfaces of the operating systems. This thesis takes the advantage of the DDS middleware to implement a 1553 serial data bus simulation tool. In addition, the tool provides XML based interfaces and scenario definition capabilities, which enable easy and quick testing and validation of component interfaces. Verification of the tool was performed over a case study using a scenario based on the MIL-STD-1760 standard.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper presents the Mission Integrated Decommutation and Analysis System (MIDAS), a multi-threaded, multi-processing application developed in Microsoft Visual C++ for Windows NT by the Air Force Development Test Center (AFDTC) Eglin AFB, Florida. The primary function of MIDAS is to support post-test processing of instrumentation data by decommutating, logging, and reporting MIL-STD-1553B or pulse code modulated (PCM) encoded data extracted from MARS-II digital tape recordings. MIDAS processes multiple data streams from a single recording, and can process multiple recordings in parallel. MIDAS also serves as a diagnostics tool for investigating data processing anomalies reported during normal production runs. MIDAS is part of an integrated suite of applications developed to provide AFDTC development test and operational test customers with quickly delivered, high-quality data products. Software development is underway to support the processing of Digital Data Acquisition and On-Board Recording Standard (DDAS) packetized telemetry data. DDAS is derived from the Consultative Committee for Space Data Systems (CCSDS) standard. [MARS-II is the digital acquisition and recording system supported by MIDAS. MARS-II was developed by DATATAPE, Incorporated, Pasadena, California. It records up to 20 gigabytes of mission data across as many as eight channels of MIL-STD-1553B or PCM encoded data. Digital recording technology provides an alternative to traditional analogbased telemetry ground systems.]

This thesis describes the design of a board-level testing platform for monitoring and driving a selected set of interfaces used in space applications. The requirements of these devices are based on the corresponding ECSS, IEEE, and TIA standards described in the theoretical part of this thesis. The designed testing device is controlled by the Xilinx Zynq-7000 system-on-chip and is connected to a control PC via an Ethernet connection. The hardware, designed on a schematic level is responsible for meeting the standards' requirements. The software part consists of a Python module for the control PC providing a set of functions to be used in the testing process and a C application for the embedded ARM processor that forwards the data through the AXI interface to the interface drivers in the programmable logic.