1. Technical University of Košice Faculty of Electrotechnic and Informatics Department of Electronics and Telecommunications Data Acquisition Systems Introduction part 1 Linus Michaeli 6 th Summer School on Data Acquisition Systems Benevento, Italy, 26.June 2006 Education and Training

2.  Structure of measuring chain. Analog part brings systematic error into measuring chain and interferences with noise sources. Measuring chain with converter selected parameter  System configuration of the measuring signal conditioning with analog multiplex  Diagnostic feedback for autocalibration and diagnostic  Feedback from the controller is dedicated to process control.

3. Measuring chain with converter selected parameter  System configuration of the measuring signal conditioning with digital multiplex

4. Errors in Signal conditioning blocks Noise sources affecting measuring signal transmission:  EMC from power line and electronic power supplies.  EMC from telecommunication transmitters (TV, AM and FM radio)  Corona effects in insulators.  Atmospheric ionisation.  Thermal noise,1/F noise, flicker noise  DC drift, instability of parameters.

5. Embedded ADCEmbedded ADC DAC pulse width modul.DAC pulse width modul. MicrocontrollerMicrocontroller Communication via busCommunication via bus Common clockCommon clock Plug&PlayPlug&Play Intelligent sensor Generalised measuring chain Is represented by Intelligent sensor Sensors, Intelligent sensors will be presented by Prof. Helena M.G. Ramos Instituto Superior Tecnico, Lisboa, Portugal

6. Basic operation in mutual conversion analog and digital signal Discretization in time and bandwidth constraint Ilustration of the aliasing effect

7. Quantisation The quantisation noise Discretization in level and quantisation noise

8.  The measuring chain could be considered as a generalised ADC Measuring chain as a generalised AD Converter  Input physical quantity x(iT), Output digital sample k(iT) Analog signal preprocessing blocks, trends and limitations: Prof.Ramon Pallas-Areny Technical University of Catalonia (UPC, Spain)  Analog conditioning block main error sources both systematic & random  Shape of transfer function with discontinuities and time sampling caused by ADC

9. ADC & DAC Transfer Curve Resolution 2 N Number of bits N Effective number of bits Full scale range FSR Signal to Noise ratio (dB) Code transition level Code bin width

10. Error sources Stochastic error sources u A : Thermal noise- Gaussian distribution of the power  2 nThermal noise- Gaussian distribution of the power  2 n Noise generated by the EM interference. General description by the power of induced voltage at the input of the DAQ  2 EMCNoise generated by the EM interference. General description by the power of induced voltage at the input of the DAQ  2 EMC Quantisation noise  2 QQuantisation noise  2 Q Systematic error sources u B : Gain errorGain error OffsetOffset Integral nonlinearityIntegral nonlinearity Error sources Distribution of systematic error parameters is based upon assumption of the uniform occurrence in the interval  G.FS,  O,  INL MAX with zero mean

11. Gain, offset and INL errors can be assessed by the „type B“ uncertainty. Total measurement uncertainty The „total noise“ can be estimated by the limits as a „type A“ uncertainty The combined uncertainty u C and expanded uncertainty U with coverage factor 2

12. ADC&DAC parameters and their testing Problems: Unambiguous definitionUnambiguous definition Explicit testing approachesExplicit testing approaches Testing methods: Required uncertainty of the instrument ensuring the metrological property of the testing stand on the accuracy level 10 % corresponds to the ADC resolution. Required uncertainty of the instrument ensuring the metrological property of the testing stand on the accuracy level 10 % corresponds to the ADC resolution. Time consumpting  Static and Dynamic Test methodsTime consumpting  Static and Dynamic Test methods Definition of the ADC and DAC parameters and Introduction to ADC testing – some non- standardized methods: Prof.Jan Saliga, Technical University of Kosice Introduction to ADC testing based on the 1241 standard discussion of basic choices concerning the 4-parameter algorithm:Prof.Istvan Kollar, University of Technology and Economics, Budapest Lecture around the 3 and 4 sine wave parameter fit:Prof.Peter Händel Royal Institute of Technology (KTH), Stockholm DAC testing: Eulalia Balestieri, UNI Sannio Benevento

13. State of the Art in the Standardisation process IEEE 1057 IEEE 1057 IEEE 1241 IEEE 1241 DYNAD DYNAD Report about activity of the IEEE TC-10 Standards:

14. Thank you for your time and attention

15. ADC & DAC Transfer Curve Effective number of bits Code transition level Code bin width Problem: How to test Static testing methods Dynamic testing methods