NI DAQ, Nanopositioner
(Tilt mirror)
Control of the focal point location is done using a piezoelectric tilt mirror for
the in plane motions
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Reference:
NARIONAL INSTRUMENT, “NI-DAQ 7, DAQmx C Reference Help ”, 2004
NARIONAL INSTRUMENT, “DAQ, 6534X User Manual”, 2001
nPoint, “C-300 Series Controller Manual”, Version 1.2, 2005
Specification
MODEL
Parameter
TILT STAGE
Typical
Maximum
UNIT
Tilt range(mrad)
8
mrad
Static stiffness
4
N/mm
Integrated sensor
Strain Gauge
Resolution
Resonant frequency
1
Interface
USB
Material
Al
kHz
unloaded
Application of Tilt mirror
•
Trapping position control with tilt mirror
Tilt mirror
Objective lens
– Controlling the position of the laser focus in two dimensional plane
perpendicular to the beam axis
– The tilt mirror is positioned at the conjugate plane of the objective
back aperture
• to minimize the loss of energy caused due to the deflection of the tilt
mirror
Application of Tilt Mirror (con’t)
• Point scan (20 Hz)
2 point
3 point
• Line scanning and circle scanning
Line
circle
nPoint Digital Controller interface
• nPoint C300 USB V1.2.5
– Provides nanopositioning control capabilities
– Graphical controls facilitate easy adjustment of control parameters,
step-response verification and enabling of advanced control modes
X, Y axis control
Interface of the Tilt mirror scanning
• User interface of optical tweezers control program
Nanopositioner Control with NI DAQ
Input data
Feedback data
Programming using
DAQ API
Generating &
collecting data
Tilt mirror
Transferring data
Objective positioner
[7]
3D laser focus position control
NI DAQ ?
•
NI DAQ (National Instrument Data Acquisition)
: Collecting and measuring the same kinds of electrical signals with
analog-to-digital and/or digital devices plugged into a PC, and
possibly generating control signals with digital-to-analog and/or
digital devices in the same PC.
PC-BASED DATA ACQUISITION
Figure referred to www.ni.com
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[8]
Two libraries for NI DAQ
- Traditional NI DAQ, difficult to understand and implement
- NIDAQmx: new library, easy to understand and implement
PCI-6534 DAQ Device
www.ni.com
PCI - 6534
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[9]
32 (5 V TTL/CMOS) digital
input/output lines
20 MHz (80 Mbytes/s) maximum
transfer rate
8, 16, or 32-bit transfers
Start and stop triggering, pattern
and change detection
32 MB onboard memory per data
path (group) (NI 6534 only)
NI-DAQ driver simplifies
configuration and measurements
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Operating Systems
•Windows 2000/NT/XP/Me/9x
• Mac OS 9*
Recommended Software
• LabVIEW
• Measurement Studio for Visual
Other Compatible Software
• Visual Basic
• C/C++
Driver Software (included)
• NI-DAQ
NI-DAQmx Key Concepts
•
Task: A task is a collection of one or more channels, timing,
triggering, and other properties that apply to the task itself.
Conceptually, a task represents a measurement or generation you
want to perform.
•
Channel: Virtual channels are software entities that encapsulate the
physical channel. The physical channel can be configured as data
output channel or data input channel.
•
Timing, Triggering: The timing section explains clocks. The triggering
section goes over the triggers such as a Start Trigger and a Reference
Trigger, Analog Edge Trigger, Digital Edge Trigger.
•
Buffer: A buffer is a temporary storage in computer memory for
acquired or to-be-generated samples.
[10]
Basic NI DAQmx Functions for PCI-6534 Device
•
Task Configuration/Control: DAQmxCreateTask (), DAQmxStartTask(),
DAQmxStopTask(), DAQmxClearTask(), DAQmxIsTaskDone(), etc.
•
Channel Creation: DAQmxCreateDOChan(), DAQmxCreateDIChan()
•
Timing: DAQmxCfgSampClkTiming()
•
Write: DAQmxWriteDigitalU8(), DAQmxWriteDigitalU16(),
DAQmxWriteDigitalU32()
•
Read: DAQmxReadDigitalU8(), DAQmxReadDigitalU16(),
DAQmxReadDigitalU32()
[11]
DAQ Flowcharts
Finite Sample Writing to DAQ device
DAQmxCreateTask
DAQmxCreateTask
DAQmxCreateDOChan
DAQmxCreateDIChan
DAQmxCfgSampClkTiming
DAQmxWriteDigitalU16
DAQmxStartTask
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Finite Sample reading from DAQ device
DAQmxCfgSampClkTiming
DAQmxStartTask
DAQmxReadDigitalU16
DAQmxStopTask
DAQmxStopTask
DAQmxClearTask
DAQmxClearTask
Example code (data output)
Include “nidaqmx.lib” in the project setting
[13]
Example code (data input)
Include “nidaqmx.lib” in the project setting
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