slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
PPT 206 Instrumentation, Measurement and Control SEM 2 (2012/2013) PowerPoint Presentation
Download Presentation
PPT 206 Instrumentation, Measurement and Control SEM 2 (2012/2013)

Loading in 2 Seconds...

play fullscreen
1 / 15

PPT 206 Instrumentation, Measurement and Control SEM 2 (2012/2013) - PowerPoint PPT Presentation


  • 158 Views
  • Uploaded on

PPT 206 Instrumentation, Measurement and Control SEM 2 (2012/2013). On- Line Data Acquisition. Dr. Hayder Kh. Q. Ali hayderali@unimap.edu.my. Data acquisition

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'PPT 206 Instrumentation, Measurement and Control SEM 2 (2012/2013)' - rebecca-odom


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

PPT 206 Instrumentation, Measurement and Control

SEM 2 (2012/2013)

On- Line Data Acquisition

Dr. Hayder Kh. Q. Ali

hayderali@unimap.edu.my

slide2

Data acquisition

is the process of sampling signals that measure real world physical conditions and converting the resulting samples into digital numeric values that can be manipulated by a computer. Data acquisition systems (abbreviated with the acronym DAS or DAQ) typically convert analog waveforms into digital values for processing

slide3

The components of data acquisition systems include:

  • 1- Sensors that convert physical parameters to electrical signals.
  • 2- Signal conditioning circuitry to convert sensor signals into a form that can be converted to digital values.
  • 3- Analog-to-digital converters, which convert conditioned sensor signals to digital values.
  • Data acquisition applications are controlled by software programs developed using various general purpose programming languages such as BASIC, C, Fortran, Java, Lisp, Pascal.
slide4

History

In 1963, IBM produced computers which specialized in data acquisition. These include the IBM 7700 Data Acquisition System and its successor, the IBM 1800 Data Acquisition and Control System. These expensive specialized systems were surpassed in 1974 by general purpose S-100 computers and data acquisitions cards produced by Tecmar/Scientific Solutions Inc. In 1981 IBM introduced the IBM Personal Computer and Scientific Solutions introduced the first PC data acquisition products.

slide5

Methodology

Source

Data acquisition begins with the physical phenomenon or physical property to be measured. Examples of this include temperature, light intensity, gas pressure, fluid flow, and force. Regardless of the type of physical property to be measured, the physical state that is to be measured must first be transformed into a unified form that can be sampled by a data acquisition system. The task of performing such transformations falls on devices called sensors.

slide6

A sensor, which is a type of transducer, is a device that converts a physical property into a corresponding electrical signal (e.g., Strain gauge, thermistor). An acquisition system to measure different properties depends on the sensors that are suited to detect those properties. Signal conditioning may be necessary if the signal from the transducer is not suitable for the DAQ hardware being used. The signal may need to be filtered or amplified in most cases.

slide7

Various other examples of signal conditioning might be bridge completion, providing current or voltage excitation to the sensor, isolation, linearization. For transmission purposes, single endedanalog signals, which are more susceptible to noise can be converted to differential signals. Once digitized, the signal can be encoded to reduce and correct transmission errors.

slide8

DAQ hardware

DAQ hardware is what usually interfaces between the signal and a PC. It could be in the form of modules that can be connected to the computer's ports (parallel, serial, USB, etc.) or cards connected to slots (S-100 bus, AppleBus, ISA, MCA, PCI, PCI-E, etc.) in the motherboard. Usually the space on the back of a PCI card is too small for all the connections needed, so an external breakout box is required. The cable between this box and the PC can be expensive due to the many wires, and the required shielding.

slide9

DAQ cards often contain multiple components (multiplexer, ADC, DAC, TTL-IO, high speed timers, RAM). These are accessible via a bus by a microcontroller, which can run small programs.

slide10

DAQ software

DAQ software is needed in order for the DAQ hardware to work with a PC. The device driver performs low-level register writes and reads on the hardware, while exposing a standard API for developing user applications. A standard API such as COMEDI allows the same user applications to run on different operating systems, e.g. a user application that runs on Windows will also run on Linux.

slide11

Input devices

  • 1- 3D scanner
  • 2- Analog to digital converter
  • 3- Time to digital converter
slide12

Hardware

  • CAMAC - Computer Automated Measurement and Control
  • Industrial Ethernet
  • Industrial USB
  • LAN eXtensions for Instrumentation
  • NIM
  • PowerLab
  • PCI eXtensions for Instrumentation
  • VMEbus
  • VXI
slide13

Software

Specialized software tools used for building large-scale data acquisition systems include EPICS. Graphical programming environments include ladder logic, Visual C++, Visual Basic, and LabVIEW.

slide14

Worksheet

The worksheet is where you create the data flow logic for the application. Select and combine the desired function modules and connect them with wires that represent the data flow.

The browser window displays a tree structure containing all available function modules as well as any saved block boxes. It also contains a navigator to quickly find specific modules in a worksheet.

slide15

Function Modules

No programming required! Configure your experiment setup easily using the drag’n’drop capability of DASYLab. Pick up the required Function Module from your favorite Modules of the module bar or use the tree of the browser window.