Applied Physics Systems 544 User manual

www.appliedphysics.com
281 East Java Drive Sunnyvale, CA. 94089 USA • 650.965.0500 • Fax: [phone] • [email protected]
Model 544
MSP430 CPU Version
Miniature Angular Orientation Sensor
User Manual

Model 544 User Manual
................www.appliedphysics.com
Copyright
Copyright 2007 - 2017 Applied Physics Systems Incorporated.
All Rights Reserved.
The contents of this manual may not be reprinted in part or whole without permission.
The contents of this manual are subject to change without notice.
Trademarks
All other brands or products mentioned are trademarks or registered trademarks of their
respective holders and should be treated as such.
Contact Information
Applied Physics Systems
Corporate Headquarters
281 East Java Drive
Sunnyvale, California 94089
USA
Phone: [phone]
Fax: [phone]
Email: [email protected]
Web: www.appliedphysics.com
Technical Support Hours:
Monday - Friday
9:00 AM - 5:00 PM
Pacific Standard Time
Document Number
250-1256-03-1117
Revision History
Revision Description Date
1 Initial draft of this manual. March 2007
2Renamed Binary Constant to Byte Constant. February 2017
Renamed Floating Constant to Float Constant.
Updated Table 1 - Model 544 System Specifications.
Updated Table 6 - Baud Rate Settings.
Added Figure 1 - Model 544 Mechanical Diagram.
Added Figure 2 - Model 544 Coordinate System and Orientation Angles.
Updated Section 6.5 - Enabling the Echoing of Incoming Commands.
Updated Table 7 - Autosend Modes.
Updated Table 8 - Averaging Output Data.
Updated Section 6.10 - Single Packet Binary Communication Modes.
Updated Table 9 - Binary Data Packets.

Model 544 User Manual
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Updated Section 6.12 - Comparison of ASCII and Standard Binary Data
Structures.
Removed Section 6.13 Changing the 544 Coordinate System (Optional).
Updated Figure 6 - Corrected ASCII Mode.
Updated Figure 8 - Model 544 Inclination versus Azimuth Error.
3Removed the following sections:
..7 - Calculating the Orientation Sensor Angles
..7.1 - Sensor Based Coordinate System
..7.2 - Definition of Orientation Angles
..7.3 - Definitions
..7.4 - Calculating Roll and Magnetic Roll
..7.5 - Calculating Inclination
..7.6 - Magnetic Heading (Azimuth)
November 2017
Added 3.1 - Coordinate System.
Added a warning about changing float constants in
6.1 - Model 544 Internal Byte and Float Constants.
Removed Table 5. Float Constants.
Revision Description Date

Model 544 User Manual
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Contents
Chapters
Chapter 1 - Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Chapter 2 - System Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Chapter 3 - Mechanical Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
3.1 - Coordinate System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Chapter 4 - Electrical Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Chapter 5 - Setting up the System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Chapter 6 - Computer Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
...... 6.1 - Model 544 Internal Byte and Float Constants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
...... 6.2 - ASCII Communication Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
...... 6.3 - Changing Data Output Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
...... 6.4 - Changing the Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
...... 6.5 - Enabling the Echoing of Incoming Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
...... 6.6 - Entering a Serial Number into the Power Up Sign On Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
...... 6.7 - Disabling the Power Up Sign On Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
...... 6.8 - Configuring for Autosend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
...... 6.9 - Averaging and Filtering Output Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
...... 6.10 - Single Packet Binary Communication Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
...... 6.11 - Autosend Binary Communication Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
...... 6.12 - Comparison of ASCII and Standard Binary Data Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Chapter 7 - Windows Software for the Model 544 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Appendix
Appendix A - Azimuth Accuracy Estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
...... A.1 - Orientation Sensor Azimuth Accuracy as a Function of the Earth’s Magnetic Field Dip Angle . . . . . . . .25
...... A.2 - Orientation Sensor Azimuth Accuracy as a Function of the Inclination . . . . . . . . . . . . . . . . . . . . . . . . . .26
Figures
Figure 1 - Model 544 Mechanical Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Figure 2 - Model 544 Coordinate System and Orientation Angles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Figure 3 - Sensor Interface Software Main Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Figure 4 - Sensor Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Figure 5 - Monitor Sensor Display Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Figure 6 - Corrected ASCII Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Figure 7 - Corrected HEX Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Figure 8 - Model 544 Inclination versus Azimuth Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Model 544 User Manual
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Tables
Table 1 - Model 544 System Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Table 2 - Model 544 Electrical Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Table 3 - RS-232 Interface Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Table 4 - Model 544 Byte Constants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Table 5 - Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Table 6 - Baud Rate Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Table 7 - Autosend Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Table 8 - Averaging Output Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Table 9 - Binary Data Packets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Table 10 - Dip Angle versus Azimuth Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

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1 - Introduction
This manual describes the Model 544 Miniature Orientation Sensor. This system is designed to
enable high accuracy measurement of the inclination, roll (toolface) and azimuth orientation
angles of the system to which it is mounted. A common application of the 544 is to measure the
orientation of borehole logging and directional drilling systems.
The 544 sensor contains both a 3-axis fluxgate magnetometer and a 3-axis accelerometer. The
combination of these two sensor systems enables the inclination, roll and azimuth angles of the
544 reference frame to be determined. Inclination and roll angles are determined from the
accelerometer subsystem, which measures the pull of gravity. After inclination and roll are known,
the magnetometer subsystem is used to determine the system azimuth angle. Knowledge of the
inclination and roll angles enable determination of the horizontal components of the earth's local
magnetic field; this information defines the azimuth angle.
The 544 system contains a microprocessor and 8 channels of 16-bit analog to digital conversion.
Six channels are assigned to the magnetometer and accelerometer outputs. One channel
provides temperature data from an internal thermometer and one channel is configured to
measure the system input voltage.
The 544 system communicates over one of two serial bidirectional interfaces that can be selected
for either TTL or RS-232 voltage levels. An ASCII character command language has been
created to facilitate communication with the 544. For example, if the ASCII string “0SD”<CR> is
sent to the unit, the 544 interprets this as a "send data" command and responds by sending over
the serial interface an ASCII string representing the value of all magnetometer, accelerometer
and temperature outputs. The leading zero in this sequence denotes the system serial number.
The 544 can also be configured to send angle data (roll, pitch and azimuth) instead of the
accelerometer and magnetometer sensor data.
An autosend data mode is included in the 544 firmware. When this mode is active, data is
repeatedly sent after power is applied to the system.
The 544 accelerometers are calibrated by placing the system in a precision rotation fixture and
systematically changing the system orientation in the earth's gravitational field. The 544 system
magnetometers are calibrated by placing the system in a precision 3-axis Helmholtz coil system,
which enables the application of known magnetic fields to the system. Both the rotation fixture
and Helmholtz coil mounting fixture have alignment pins and reference surfaces, which mate to
the 544 reference surface.
When the system is calibrated over a temperature range, data is read from the system at
temperature intervals between the minimum and maximum temperature specification. For
example, for calibration over the interval of 0°C - 75°C, data is read at 25°C temperature intervals
between 0°C and 75°C. The data taken at each temperature includes scale, offset and sensor
alignment data. The recorded data is then used to create a look up table for scale offset and
alignment corrections. This table is then downloaded into the 544 internal EEROM memory,
where it can be accessed by the system internal microprocessor. Corrections to the read sensor
data can then be made by the internal microprocessor system before data is transmitted.

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Chapter 1 - Introduction
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2 - System Specifications
The system specifications for the 544 are shown in Ta ble 1 .
Specifications are subject to change without notice.
Table 1. Model 544 System Specifications
Specification Value Notes
Angular Accuracy
Azimuth ±1.2° Inclination 90°
Inclination ±0.4° Inclination 90°
Roll ±0.4° Inclination 90°
Power
Voltage +4.9 to +12 VDC
Current 55 mA
Operating Temperature 0°C - 70°C Optional range of 0°C to 125°C available
Vibration 10 g RMS, random 20 - 250Hz
Shock 750 g 1ms half-sine
Size 0.75" x 0.80" x 4.6"
Mass 50 grams
Digital Outputs
Logic Level TTL or RS-232 User selectable
Baud rate 300 – 9600, 19200, 38400
baud User selectable
Protocol ASCII text or binary User selectable
Leads 27" flying leads Color coded
Data output speed in autosend mode: Data rates listed are for a filter setting of 30 Hz.
ASCII angle mode 6 Samples/second
ASCII sensor mode 9 Samples/second
Binary sensor mode 18 Samples/second

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Chapter 2 - System Specifications
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