Instrumentação Suportada em Computadores Pessoais Instrumentation

Transcription

1 1 Instrumentação Suportada em Computadores Pessoais PC-Based Instrumentation A. Lopes Ribeiro

2 2 Objectives To give the students the ability to design and implement automated data acquisition systems, (measurement and/or control), based on personal computers.

3 3 Objectives Previously, the measurement systems were based on single instruments that were manually controlled through a front panel. Nowadays, the evolution of the personal computers (hardware & software) is fuelling one important change: the measurement instruments are a combination of PCs, with graphical programming interfaces and measurement equipment (instrumentation hardware).

4 Course Plan Theoretical Classes Laboratory Classes Lab works (three lab sessions each): They correspond to the design and implementation of a automated acquisition system which uses data acquisition boards and equipments remotely controlled via a standard interface (IEEE 488 or other). Some works are performed in a single lab class: they illustrate the interface operation in measurement systems, e.g.: RS232 interface. 4

5 Examination Methods The assessment has three components: Continuous evaluation: corresponds to the several laboratorial works executed by the students; Final Project: corresponds to a final work. Final Presentation: corresponds to the project presentation on seminar by the end of semester. The final grade is determined as follows: Final Grade = 0,3 x Laboratory Works + 0,7 x Final Project Final Project Grade= 0,7 x Contents + 0,3 x Presentation 5

6 6 Chapter 1 - Introduction Evolution of the test and measurement systems Constitution of an acquisition system Instrumentation systems architecture based on External Acquisition Systems Acquisition Systems Using the PC Channels

7 7 Data Acquisition Systems PC Controler ` (a) ` (b) Equipment Normalized protocol Internet Equipment Control and communications channel Equipment Equipment ` Equipment 2 U 1 U 4 U PC Controler with interface Signal Conditioning (c) (d)

8 Chapter 2 Automated Measuring Systems Introduction Circuit tests Tests in-circuit Functional or benchmark tests Tests based on Substitution Tests by Comparison Semiconductor and Components tests Performance of an automated testing system 8

9 9 Capítulo 3 - Software LabView MATLAB

10 Chapter 4 Communication between Systems Introduction Concepts and definitions Data transmission Signal codes Series and parallel transmission Interface Protocol OSI Model Transmission Control and management synchronous and asynchronous transmission 10

11 11 Chapter 5 - Series communication standards e used in measurement systems (i) Introduction EIA RS232c Standard General aspects Transmission speed baud rate RS232 structure Electrical and physical characteristics Functional aspects

12 12 Chapter 5 - Series communication standards e used in measurement systems (ii) RS232c, RS423, RS422, RS485 Standards 20 ma current interface Conversion to the series standard: UART UART structure

13 13 Chapter 5 - Series communication standards e used in measurement systems (iii) Universal Series Bus (USB) Introduction USB channel description USB channel topology Physical interface Protocol and Operation modes Communication efficiency

14 14 Chapter 5 - Series communication standards e used in measurement systems (iv) Channel IEEE 1394 Introduction Channel IEEE 1394 characteristics Physical interface Channel topology Protocol

15 15 Chapter 6 - Parallel communication standards used in measurement systems Introduction Centronics parallel interface IEEE 488 (GP-IB) interface Introduction General aspects GPIB structure Electrical and mechanical characteristics Functional aspects Operational examples IEEE 488.2

16 16 Chapter 7 - Standard Commands for Programmable Instruments (SCPI) Introduction Message syntax and style Message types Command structure Model for SCPI instruments

17 17 Chapter 8 - Protocols in use in instruments with platforms VXI Standard Historical introduction General aspects Electrical and mechanical characteristics Architecture Communication protocols Conclusion PXI Standard General aspects PXI standard specifications LXI Standard Introduction General aspects

18 18 Chapter 9 Measurement Systems using instrumentation connected to the PC buses (i) Acquisition and control boards Cannel structures Channel data transfers Scrutiny transfers Interrupt transfers DMA transfers

19 19 Chapter 9 - Measurement Systems using instrumentation connected to the PC buses (ii) Acquisition and control boards Boards with analog inputs Single and differential inputs Resolution, dynamic range and accuracy of ADCs Sampling techniques ADC boards with analog outputs ADC boards with digital I/O ADC boards with timers

20 20 Advanced Instrumentation Laboratory

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