Transcript Document 7582399

Hall Probe Calibration System
Using LabVIEW
Joseph Z. Xu
August 11, 2003
APS INSERTION DEVICES
The magnetic field spatial distribution profiles of the APS Insertion
Devices (ID) are characterized with Hall Probe Magnetic Measurement
System
Hall Effect and Hall Probe
B
Magnetic
field_
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VH
I
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+
+
+
+
+
I
B
VH
I Electric
current
Hall Effect
Hall Probe
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Hall Probes are used to characterize the magnetic field
spatial distribution profiles of the APS Insertion Devices (ID)
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The Hall Probe Calibration System is designed to calibrate the
Hall Probes
Hall Probe Calibration System
The Hall Probe Calibration System consists of:
Dry Cooper
A Magnetic
Power Supply
(MPS-853)
GPIB
RS-232
A Reference
Teslameter
(DTM-141)
A Motorized
Probe Stage
(SmartMotor)
An Electrical
Magnet
An NMR
Teslameter
(PT-2025)
A Multimeter
(HP-3458A)
NMR Theory of Operation
Applied magnetic field
B
B
Precessionnal
orbit
Spinning
nucleus
Ground State
ΔE = μB/I;
Excited State
f = ΔE/h = GB;
G = μ/hI;
B: static magnetic field
μ: nuclear magnetic moment
I: spin quantum number
f: resonance frequency
Operation Procedure
Calibrating Hall Probe
DTM-141 Probe
NMR Probes
Electric Magnet
123 456
Motorized stage
Electric Magnet Top View
I’MPS
B’EM
B DTM
IMPS
B EM
PSM
B NMR
VHall
What is LabVIEW?
A graphical programming language
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Compiled graphical development environment
Similar to flowcharting
Virtual Instrument
• Each program is called a Virtual Instrument (VI)
• Each VI has a Front Panel and a Block Diagram
Front Panel: User Interface
(MEDM)
Block Diagram: Source Code
(IOC Application)
Front Panel: User Interface
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Graphical user interface
Pre-built user interface objects
Block Diagram: Source Code
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Intuitive flowchart-like code
Hundreds of pre-built measurement subVIs
Self-documenting
Debugging
Step in, single step, step out
Highlight execution
Application Builder
Compiler Creates:
Application.exe and
Application.ini files
Installer Creates
data.cab, install.msi
InstMsi.exe, setup.ini,
InstMsiW.exe, and
setup.exe files
Hall Probe Calibration System Software
Main Panel
Hall Probe Calibration System Software
Reference
Teslameter
(DTM-141)
DTM-141 Reference Digital Teslameter Panel
Hall Probe Calibration System Software
NMR
Teslameter
(PT-2025)
PT-2025 NMR High Precision Teslameter Panel
Hall Probe Calibration System Software
Magnetic
Power Supply
(MPS-853)
MPS-853 Magnetic Power Supply Panel
Hall Probe Calibration System Software
MPS-853
Magnetic
Power
Supply
Panel
Interlock
Pull
Down
Menu
Hall Probe Calibration System Software
Multimeter
(HP-3458A)
HP-3458A Panel
Hall Probe Calibration System Software
Motorized Probe Stage
(SmartMotor)
Motorized NMR Probe Stage Panel
Hall Probe Calibration System Software
Plot Panel
Hall Probe Calibration System Contents
System Hardware:
1. Danfysik System 8000 MPS-853 Precision Magnet Power Supply
System
2. Electric Magnet
3. Metrolab PT-2025 High Precision NMR Teslameter System
4. Motorized NMR Probe Support Stage System Powered by
Animatics SmartMotor Servo Motors
5. Group 3 DTM-141 Digital Teslameter System
6. HP 3458A Multimeter System
7. PC with a GPIB PCI card, a RS-232 port, 600 MHz or higher
CPU, 128 MB or more RAM, and 130 MB or more free HD.
System Software and Documents:
1.
2.
3.
4.
Windows XP/2K/NT/98 OS.
PC based software package with installer on a CD
User’s Guide
Operation Method of Procedure
Next Project: Integral (Stretch Coil)
Measurement System Upgrade
Field integral (along the z direction) Theory of Operation

Iy 

 B dz
Ix 
y

Horizontal Component
Y
1
I y   1  2   3   4 
4
4
1
X
Y
3
x

Vertical Component
4
 B dz
3
2
1
2
Ix 
1
 1  2   3   4 
4
Key System Requirements
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Motion Control: SmartMotor via RS-232
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2x4 axis: x(0-400mm), y(0-400mm), z(0-6000mm), w(0-360)
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Motion Readout: Linear (x, y, and z) and Rotary (w) Encoders
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DAQ: Coil EM Voltage Measurement
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Synchronization: Absolute Angle Position vs. Coil Voltage
Measurement w/ at 1.5 kS/s
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Linear encoder resolutions: 25 μm absolute position
Rotary encoder resolutions: 0.1deg absolute angle position
Linear stage speed: up to 50 mm/s at z direction
Rotary stage speed: up to 1 revolution per second
Resolution: 16 bit (5 digits)
Sampling rate: 1.5 kS/s
Triggering must be done in referencing of absolute positions.
Digital I/O Noise Control: 10-7
Current System Architecture
System A (on the 6 meter bench)
Stepping Motor Drivers
Stepping Motor Power Supplies
PCI
NIVXI
PCI
GPIB
VME
VME44
w-Encoder
Board
Magnetic Flux
Integrator
VMEX
xyz-Encoder
Board
Amplifier
To the Stepping Motors
From the encoders
From the Coil
Current Issues:
1.
2.
3.
Flux start point and finish points (positions) are not well defined.
Only 4 data points are measured and data analysis is not feasible.
System is Windows 3.1 based and software is not upgradeable.
Current System Architecture
System B (on the 3 meter bench)
To the SmartMotors
From the Coil
RS-485
RS-232 to
RS-485 Converter
RS-232
PowerDAQ 16 bit
PCI ADC Card
Amplifier
Current Issues:
1.
2.
3.
Positioning and measurements are “synchronized” by PC CPU time using
software. (~ 3 ms?)
Start and Finish positions/times are not well defined.
System is RedHat Linux based and hard to maintain.
Proposed System Architecture
From x, y, z, and w
encoders
TCP/I
P
PXI
FPGA I/O
w/ built in
16 bit ADC
RS-232
From the Encoders
From the Coils
To the SmartMotors
Key Features:
1.
2.
3.
4.
Integrated real time encoder readout, triggering, and Coil voltage
measurement.
TCP/IP Interface, securely access the system remotely, anywhere, anytime.
Commercial off-the-shelf components.
Same hardware can be used for both 6 meter bench and 3 meter bench Hall
Probe Measurement Systems.
Why PXI?
PXI: PCI eXtensions for Instrumentation
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2.
3.
A specification designed explicitly for industrial test and control applications.
Industry open standardized PCI backplane at 132 MB/s or 1 Gbps (32
bits@33MHz) plus integrated timing and triggering.
Well supported by all major operating systems.
4. Large selection of instruments and modules.
5.
Low cost and ease of use.
See www.pxisa.org for detailed specifications
Conclusion
For isolated control and data acquisition systems, PC based
and/or PXI based platform with LabVIEW, Visual Basic, or
Visual C++ development tools shall be adequate.
Hall Probe Calibration System Demo Diagram
RS-232
SmartMotor
NMR Probes
TCP/IP
802.11
GPIB
Electric
Magnet
Magnetic
Power Supply
(MPS-853)
Reference
Teslameter
(DTM-141)
NMR
Teslameter
(PT-2025)
Digital
Multimeter
(HP-3458A)