NI DAQ, Nanopositioner(Tilt mirror)

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

Control of the focal point location is done using a piezoelectric tilt mir-ror for the in plane motions

Specification

MODEL TILT STAGE

Parameter Typical Maximum UNIT

Tilt range(mrad) 8 mrad

Static stiffness 4 N/mm

Integrated sensor Strain Gauge

Resolution

Resonant frequency 1 kHz unloaded

Interface USB

Material Al

Application of Tilt mirror• Trapping position control with tilt mirror

Objective lens Tilt mirror

– 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 objec-tive back aperture

• to minimize the loss of energy caused due to the deflection of the tilt mirror

• Point scan (20 Hz)

• Line scanning and circle scanning

Application of Tilt Mirror (con’t)

2 point 3 point

circleLine

nPoint Digital Controller interface

• nPoint C300 USB V1.2.5– Provides nanopositioning control capabilities– Graphical controls facilitate easy adjustment of control param-

eters, 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

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Nanopositioner Control with NI DAQ

Generating & collecting data

Programming using DAQ API

Transferring data

Input data

Feedback data

Objective positioner

Tilt mirror

3D laser focus position control

[8]

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

Two libraries for NI DAQ - Traditional NI DAQ, difficult to understand and im-

plement - NIDAQmx: new library, easy to understand and im-

plement

[9]

PCI-6534 DAQ Device

PCI - 6534

www.ni.com

• 32 (5 V TTL/CMOS) digitalinput/output lines

• 20 MHz (80 Mbytes/s) maximumtransfer rate 8, 16, or 32-bit transfers

• Start and stop triggering, patternand change detection

• 32 MB onboard memory per datapath (group) (NI 6534 only)

• NI-DAQ driver simplifiesconfiguration and measurements

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

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NI-DAQmx Key Concepts

• Task: A task is a collection of one or more channels, timing, trig-gering, and other properties that apply to the task itself. Concep-tually, 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.

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Basic NI DAQmx Functions for PCI-6534 Device

• Task Configuration/Control: DAQmxCreateTask (), DAQmxStartTask(),

DAQmxStopTask(), DAQmxClearTask(), DAQmxIs-

TaskDone(), etc.

• Channel Creation: DAQmxCreateDOChan(), DAQmxCreateDIChan()

• Timing: DAQmxCfgSampClkTiming()

• Write: DAQmxWriteDigitalU8(), DAQmxWriteDigitalU16(),

DAQmxWriteDigitalU32()

• Read: DAQmxReadDigitalU8(), DAQmxReadDigitalU16(),

DAQmxReadDigitalU32()

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DAQ Flowcharts

DAQmxCreateTask

DAQmxCfgSampClkTiming

DAQmxCreateDOChan

Finite Sample Writing to DAQ device

DAQmxWriteDigitalU16

DAQmxStartTask

DAQmxStopTask

DAQmxClearTask

DAQmxCreateTask

DAQmxCfgSampClkTiming

DAQmxCreateDIChan

Finite Sample reading from DAQ device

DAQmxReadDigitalU16

DAQmxStartTask

DAQmxStopTask

DAQmxClearTask

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Example code (data output)Include “nidaqmx.lib” in the project setting

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Example code (data input)Include “nidaqmx.lib” in the project setting