Lab Data Acquisition

1
Lab Data Acquisition
2
Important Considerations

• Sampling Rate
• Intended Application
• Input Ranges (high or low voltages)
• Analog Inputs, Analog Outputs, Digital I/O

3
Resolution

• 12 bit vs. 16 bit?

Resolution range/2N (N number of bits)
e.g., for a range of 10 Volt max
signal Resolution (_at_12 bit) 10/212 2.44
mV Resolution (_at_16 bit) 10/216 0.15 mV
4
Lab Standard

• Hardware
• Windows PC
• National Instruments
• Hewrett Packard
• Keithly/Metrabyte/Computer Boards
• Software
• Visual Basic/C
• Lab Window cvi
• LabView

5
Hardware Categories

• Plug-in Acquisition Boards
• Signal Conditioning and Accessories
• Multiplexer
• Attenuation Filters
• Screw Terminal Assemblies (STA)
• PC Instrument Products (PCIP)
• Oscilloscope
• Waveform generator
• Multimeter
• Interfaces

6
Hardware Case Example

• DAS-16 KM board
• DAS-1602 KM board
• EXP-32 CB expansion board
• DDA-06 CB analog output board
• Four STAs

• AT-MIO-16H9
• Lab PC, Lab PC
• PCMCI Daq_card
• GPIB PCII/IIA
• Four STAs

7
Getting at the bits

• Low-level
• bit values in memory (on A/D board or on PC)
• register-level calls
• High-level
• C, Basic
• Visual Basic
• pre-defined functions
• Very High-level
• Lab View
• Labtech Notebook
• graphical user interface

out(h300),4 out(h30f),8 pin(h3ff) ...
DA1.initialize DA1.start pDA1.in ...
P Sensor
?20
D/A 1