HIGH SPEED DATA ACQUISITION SYSTEMRENISH THOMAS EECS 71312/08/2015

CONTENTS:•Why focus on data acquisition systems•Hardware architecture• Acquisition system•Distribution system• Storage system• Performance metrics

WHY FOCUS ON DATA ACQUISITION SYSTEM• This is the first link between the analog and

the digital world.• Any errors at this stage would wreak havoc

on the entire system even if the rest of the system is state of art and the best.

WHY FOCUS ON DATA ACQUISITION SYSTEM ( SPEED AND STABILITY)• Many applications in real world requires measuring of

really high frequency signals, such as RADAR and instrumentation signals typically in Giga hertz range and Nyquist rate must be satisfied while sampling and all in real time .

• https://en.wikipedia.org/wiki/AN/SPS-49

THE ARCHITECTURE (SYSTEM UNDER CONSIDERATION):• The three primary stages are the

acquisition, distribution and the storage section.

ACQUISITION SYSTEM• SIGNAL CONDITIONING:• Impedance matching• Range adjusting• Buffer• Filter• Gain adjusting• ADC matching

ACQUISITION STAGE• Main optimizations : using both the edges of a stable

oscillator. ( double frequency but same stability and jitter)• In this system 1.5 Ghz stable clock is used to obtain an

effective frequency of 3 Ghz but maintaining the original stability.

• http://www.ni.com/white-paper/7284/en/

DISTRIBUTION STAGE•Primary optimizations:• Used a fast FPGA or processor for distribution.• Used optical interfaces with the storage units (SFP) small

form pluggable.• Data division technique.

OPTICAL LINK ADVANTAGES OVER ELECTRICAL LINK• Higher transfer rates ( Bandwidth)• Low EM interference• Attenuation , security (cross talks ) is

reduced and many others.

• http://www.diamond-fo.com/en/tools/product-detail?id=789d70b8-ce83-4a33-8e55-6b5fbe074ba8

STORAGE SECTION• Primary optimizations:• using solid state memory over mechanical platter

device.• used dedicated processors for storing into the

computer mainframe and for retrieving from the computer.

ADVANTAGES OF SOLID STATE OVER MECHANICAL MEMORIES

• http://innodisk.tumblr.com/post/75502619595/solid-state-drives-for-point-of-sale-systems

PERFORMANCE METRICS• SNR achieved 45db at 1.5 Msps

PERFORMANCE METRICS• BER ( Bit error rate): maximum of 2.1*10^-6

CONCLUSIONS• Modern technologies like optical interfaces

instead of electrical interfaces , solid state drives instead of mechanical drives and high speed dedicated processors for acquisition and storage can be used to obtain superior performance in an acquisition system.

FUTURE IMPROVEMENTS• Use Flash memories and improve on speed

and cut down on memory refresh.• Use parallel sampling to obtain higher

sampling rates with comparable SNR and BER.

REFERENCES• [1]. IEEE : Li Nan, Nie Hongshan, Wang Yinan, Liu Haijun, Xu Xin,

Sun Zhaolin, Xu Hui, High Speed Real-Time Data Acquisition System Based on Solid-state StorageTechnique ,, 2011 Second International Conference on Digital Manufacturing & Automation.

•  [2]. IEEE :Rahiman A.R,: Sumari, Solid State Disk: A New Storage Device for Video Storage Server, International symposium on Information technology 2008, IT Sim 2008.

• [3] advantages of optical link over electrical link http://www.doc.ic.ac.uk/~nd/surprise_97/journal/vol4/sm27/adv.html

• [4] Advantages of SSD over mechanical devices http://innodisk.tumblr.com/post/75502619595/solid-state-drives-for-point-of-sale-systems

ANY QUESTIONS