Model 547 Model 548 - 北京诚思嘉科技有限公司Beijing iGyro
Contents
1. When binary constant 09 is set to any value other than 0x5a the system baud rate is9600 Table 5 Baud Rate Settings Baud Rate Byte 10 Value 300 0x35 1200 0x33 2400 0x32 4800 0x31 9600 0x30 6 5 Configuring for Autosend Mode To configure the 547 for Autosend in either ASCII or Binary data format and in one of the three following output modes binary Constant 01 must to be set to Ox5A and binary constant 08 needs to be set in accordance with Table 6 Table 6 Autosend Modes Binary 08 Value Binary 02 Value Autosend Mode and Format 0x00 Send ASCII raw sensor data un calibrated Accel and Mag etc continuously on power up 0x10 0x02 Send ASCII sensor data calibrated Accel and Mag etc continuously on power up 0x03 Send ASCII angle data computed Toolface Inc and Azimuth etc continuouslyon power up 0x11 Ignored when Byte 0840x10 Send Binary Data Continuously in Sensor Mode calibrated Accel and Mag etc on power up 0x12 Ignored when Byte 0840x10 Send Binary Data Continuously in Angle Mode computed Inc and Az etc on power up Note If binary constant 35 0x10 is set it will be to insert a small time delay between data packets optional 6 6 Averaging and Filtering of Output Data Averaging of the acquired data can be enabled by setting binary constant 23 according to Table 7 Table 7 Output Data Averaging and Filtering Binary C2. Y 3y Applied Physics P Systems Model 547 Model 548 Directional Sensors 430 CPU Version Technical Reference and User Manual SS S E Applied Physics Systems 281 East Java Drive Sunnyvale CA 94089 USA Document Number Rev 1 1_FEB2011 Models 547 548 Technical Reference and User Manual 2011 Applied Physics Systems Inc All RightsReserved 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 281 East Java Drive Sunnyvale CA 94089 USA 650 965 0500 Fax 650 965 0404 Email service appliedphysics com Web www appliedphysics com 2 a Rev 1 1_FEB2011 Tae Models 547 548 Technical Reference and User Manual Contents 1 Introduction on page 4 2 Description of the Equipment on page 4 3 System Specifications on page 5 4 Mechanical Features on page 5 5 Electrical Interface on page 5 6 Computer Interface on page 6 7 Definition and Method of Calculation of the Orientation Sensor Angles on page 15 8 Figures on page 18 Tables Table 1 547 548 System Specifications on page 5 Table 2 Binary Constants on page 6 Table 3 Floating Constants frequently used on page 7 Table 4 Output Data Format on page 8 Table 5 Baud Rate Settings
3. grated Products or the LT1019 Linear Technology are suitable for constructing an RS232 to TTL interface The best way to determine if communication with the 547 has been established is to observe the presence of the 547 sign on message that is transmitted at 9600 baud when power is turned on The sign on message for the 547 is APS S NXxXxXx Ver 3 72 BowDip In the above messages the x s represent the unit serial number 6 1 547 Internal Constants The operating characteristics of the 547 are controlled by the value of internal binary constants Table 2 shows the most important constants Table 2 Binary Constants Binary Constant Function 00 Enables echoing when non zero 01 Enables autosend upon power up when 5A 02 Enables sensor A D count output when zero sensor output in Gauss and Gees when 2 and angle output roll inclination azimuth when 3 and Alternate labels ROLL PITCH HEAD 05 Controls sending of power up sign on message default 0 message enabled 08 Sets power on mode e g 10 enables ASCII autosend upon power up 09 Baud rate lock must be 5A if any baud rate other than 9600 is used 10 Sets baud rate 23 Sets up averaging of the output 35 Sets delay between transmissions in autosend mode In order to change the internal system binary constants a write enable command must first be issued This is 0l lt CR gt Where 0 is zero 1 is the letter 1 and
4. hnical Reference HHLA CICI CICO Temperature is decoded by converting to decimal and dividing by 100 TEMP 087E 2174 100 21 74 C The ANALOG ANA1 MSB and ANALOG ANA1 LSB transmission represents the 547 power voltage This voltage can be decoded by dividing by 100 ANA1 sensor power voltage 320 800 100 8 0 V The ST byte 0x80 is a status byte without meaning for 547 sensor The CS byte is a checksum The checksum is calculated by taking the lower byte from the sum of all the bytes in the transmission except for the CS byte SOT byte and EOT bytes The ST byte is included in the checksum calculation That is the bytes highlighted above in bold characters are included in the checksum calculation For the above trans mission the sum for checksum is calculated as follows OE 0E 0A B4 F6 46 F2 4A 00 91 12 67 08 7E 03 20 80 0585 where the lower byte of the sum is taken as CS checksum value 0x85 6 9 2 Angle Mode Consider the following examples of data transmissions in Angle Mode from a 547 sensor one in ASCII mode and one in standard binary mode ASCII ROLL 61 89994 MAGROLL 270 42422 PITCH 35 14559 MAG 0 43326 HEAD 244 58969 GRAV 1 00477 TEMP 25 528 DA 58 895 where ROLL is gravity roll or toolface PITCH is inclination HEAD is Azimuth MAGROLL is magnetic roll MAG is the total magnetic field GRAV is the total gravity field and DA is the magnetic field dipangle ST
5. the bytes highlighted above in bold characters are included in the checksum calculation For the above transmission the sum for checksum is calculated as follows 02 69 0A 8F 01 5F 0F 59 09 8D 27 3F 09 F3 03 20 80 040D where the lower byte of the sum is taken as CS checksum value 0x OD 6 10 Azimuth Accuracy as a Function of the Earth s Magnetic Field Dip Angle Orientation sensors measure the horizontal component of the Earth s magnetic field using accelerometers to deter mine vertical At high magnetic field dip angles the vertical component of the magnetic field becomes much larger that the horizontal component This has the consequence that small uncertainties in the direction of down or small mis alignments of the sensors can result in large errors in azimuth At a dip angle of 90 degrees there is no horizontal component and an orientation sensor based upon the measurement of acceleration and magnetic field will no longer be able to determine azimuth The following table gives expected errors in azimuth due to sensor errors of 1mg for accelerometers and 0 5mG for the magnetometers These errors could arise from measurement inaccuracy or sensor misalignment It is assumed that the pitch is in the middle range 20 to 20 degrees The errors were nearly independent of azimuth and roll Accuracy may be less than shown for small dip angles due to imperfect calibration and other systematic errors but will be less than 0 3 degre
6. lt CR gt is a carriage return Rev 1 1 FEB2011 6 TRN V Applied Physice er Manual Computer Interface When this command is sent to the 547 it will respond with the reply enabled To write binary constant 02 03 the command OWCO2b03 lt CR gt OWriteConstant02binary03 is issued After receiving this and acting upon it the 547 will respond with the reply done The reading of internal constants can be accomplished by issuing the command OSCO2b lt CR gt When this command is sent the 547 will respond by sending the value of constant 02 Wildcards are also recognized The command OSC b will cause the 547 to send the value of all internal binary constants In addition to internal binary constants the 547 also has a number of float constants These are used to store the cal ibration data in the 547 Flash memory These constants can be read by using the commands OSC f lt CR gt for all constants OSCO6F lt CR gt for constant 06 The most important floating constants are shown in the following table Table 3 Floating Constants frequently used Float Constant Function 04 X Magnetometer Base Offset 05 Y Magnetometer Base Offset 06 Z Magnetometer Base Offset 07 X Accelerometer Base Offset 08 Y Accelerometer Base Offset 09 Z Accelerometer Base Offset 10 X Magnetometer Base Scale 11 Y Magnetometer Base Scale 12 Z Magnetometer Base Scale 13 X Accelerometer Base Sca
7. magnetic toolface is defined as the angle of counterclockwise rotation about the X axis looking in the positive X axis direction required to zero the Y axis magnetometer output and position the Z axis magnetometer so that its output polarity is negative Magnetic roll is useful in defining the 547 s orientation when inclination is near vertical generally less than 5 and also in situations where accelerometer data is compromised due to heavy vibration conditions downhole In this situation g and g are near zero and roll and azimuth calculations become less accurate Rev 1 1_FEB2011 15 ty z v4 Definition and Method of Calculation of the Orienta Models 547 548 Technical Reference and User Manual 7 3 Definitions The following sections describe equations for determining the 547 orientation angles These equations make use of the following definitions g accelerometer x axis output g accelerometer y axis output g accelerometer y axis output H magnetometer x axis output H magnetometer y axis output H magnetometer z axis output 7 4 Calculation of Roll and Magnetic Roll The roll angle 0 is determined by using the following equations 0 lt 0 lt 27 cos 0 g g g 7 sin 0 g gy 9 tan 0 g g Roll is 0 when g 0 and g gt 0 Roll is 2x radians when g 0 and g lt 0 When the x axis is near vertical inclination lt 5 the quantities g and g become very
8. small and the above expressions yield a less accurate value of 8 In this sit uation magnetic roll is often used to determine the angular orientation of the 547 about the longitudinal x axis Mag netic roll Om is given by the following 0 lt 0 lt 27 sin Om HY Hy H2 cos m H H H 7 tan 0 Hy H 7 5 Calculation of Inclination Inclination is calculated as follows 0 lt lt 27 cos g g sin gy 92 9 1 2 tan gy 977 9 and g g gy g Inclination is O when the 547 X axis is pointed down and 90 when horizontal 7 6 Magnetic Heading Azimuth We first give expressions for the magnetic field in a horizontal reference defined by X1 Y1 Z1 where X1 is aligned with the projection of the 547 X axis in the horizontal plane and Z1 is down 2 2 2 2 Ha H gy 9 H 9y9x H 9 92 9 dy g 2 2 Hy Hyg H 9y dy 9 16 Rev 1 1_FEB2011 s4 z v4 Models 547 548 Technical Reference and User Manual Definition and Method of Calculation of the Orientation H21 H 9x Hygy H 9 g Magnetic heading is then given by 0 lt lt 27 cos H H Hy sin Hy Hx H 2 2 tan Hy4 Hy Hg H 92 9 Hx 9gy 9z 7 H 9y9x 7 H29x92 Magnetic heading is 0 when the 547 X axis points North and 7 2 radians when it points East Rev 1 1_FEB2011 a x 4 17 Figures
9. to the 547 to obtain data The reflected data is also sent out as an ASCII data stream complete with carriage returns and line feeds so that it can be Rev 1 1_FEB2011 ay l R 5 Computer Interface Models 547 548 Technical Reference and User Manual easily displayed on a PC video terminal provided a TTL to RS232 conversion is made by the user The binaryPC protocol is used for high speed computer to computer interchange In this case one byte is sent to request data The 547 then responds with a multi byte data packet containing the desired data plus header and checksum The system internal constants include a number of byte and floating constants Generally byte constants are used to control the system operating modes Floating constants are employed to scale the output data and correct it for tem perature variations 6 Computer Interface The computer interface of the 547 System is a TTL level serial interface In the standard configuration data is transmit ted to the 547 on pin 1 and transmitted out of the 547 on pin 2 The default baud rate is 9600 with one stop bit and no parity In order to communicate with an external personal computer PC the TTL levels of the 547 must be shifted to the RS232 levels used by the serial ports on all PCs TTL levels generally are 5V mark and Ov space whereas RS232 levels are generally 5 to 12V mark and 5 to 12V space Integrated circuits such as the Max 232 Maxim Inte
10. xx integer value from 10 to 100 As with any filter operation the lower the filter cutoff frequency the slower the response Any filter value of 10 100 Hz is valid and the factory default setting is 30Hz Use of filter values below 10Hz attenuates the signals significantly there fore filter values less than 10 Hz should not be used 6 7 Single Packet Binary Communication Modes In addition to an ASCII communication mode the 547 also has several binary communications modes Single data packet binary communications are initiated by an external computer by the issuance of a single byte com mand e g ASCII 128 On some computers these commands can be sent from a terminal emulator program by hold ing the control key down and typing the command number on the number pad on the right side of the keyboard Command Command Definition ASCII 128 Send sensor data in binary format ASCII 131 Send angle data in binary format The 547 upon receiving one of these commands responds by sending a binary data packet with one of the structures described below Command lt 128 gt Sends All Data in an encoded Binary Format The data is returned as lt lt Sent First lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt s lt lt lt lt lt lt lt lt lt lt Sent Last lt lt lt lt lt SOT gt lt MX gt lt AX gt lt MY gt lt AY gt lt MZ gt lt AZ gt lt MT gt lt V gt l
11. ANDARD BINARY IN ANGLE MODE SOT ROLL MAGROLL PITCH MAG HEAD GRAV TEMP ANA1 ST CS EOT 10 0269 OA8F O1L5F OF59 098D 273F O9F3 0320 80 OD TFFF 547 binary data packets will always start with a header byte 0x10 and end with two bytes Ox7FFF The data is always sent most significant byte MSB first then least significant byte LSB Angle data downhole voltage data ANA1 and temperature data TEMP are sent as 16 bit signed integers Angle values can be decoded by first converting to decimal and then dividing by 10 Temperature value and voltage value are decoded by converting to decimal and dividing by 100 Total magnetic field and total gravity are decoded using the same conversion to decimal and then divided by 10 000 In the above transmission ROLL 0269 617 10 61 7 MAGROLL OA8F 2703 10 270 3 PITCH 015F 351 10 35 1 MAG 0F59 3929 10 000 Gauss G HEAD 098D 2445 10 244 5 GRAV 273F 10047 10 000 1 0047 Gee g TEMP 09F3 2547 100 25 47 C ANA1 sensor power voltage 0320 800 100 8 0 V The ST byte 0x80 is a status byte without meaning for 547 sensors Computer Interface Models 547 548 Technical Reference and User Manual The CS byte is a checksum The checksum is calculated by taking the lower byte from sum of all the bytes in the trans mission except for the CS byte SOT byte and EOT bytes The ST byte is included in the checksum calculation That is
12. Models 547 548 Technical Reference and User Manual 8 Figures Figure 1 547 548 Micro Orientation Sensor Outline Drawing B 1250 Allgnnent Fin i 1 8 L0 375 Loe 1895 4X 4 40 TAP 14 OP Axis Orientation 18 Rev 1 1_FEB2011 Madalc amp IEAA Tachnical Raferanca and rMan Models 547 548 Technical Reference and User Manual Figures Figure 2 Connection Diagram for the 547 Connector Mating Connector 5 oono0oaoan A wnun CONNECTOR MDOMSSHO03P MDMSPHOO3L Eunct ion Serial in TTL Seriol out TTL t5V to 12V e50 na No Connect Ground No Connect No Connect No Connect No Connect O0000 OoO000 Alignment Pin 1250 Alignment Pin 0938 19 Figures Models 547 548 Technical Reference and User Manual Figure 3 Coordinate System of 547 548 NORTH Alignnent Pins SOUTH DORN sensor smali al iganent pin sensor al iganent 2 pin Azimuth Magnetic roll 45 Sin Queer Hy Hz 1 2 Cos On He Hy Hz 1 2 Gravitational Rol 230 Direction of drilling Sin m 7 Y 9y 9z 172 Cos On 3y 9y 9z2 1 2 When pointed North or South and horizontal magnetic roll and gravitational roll differ by 180 This ensures that when pitching from vertical to horizontal without changing the rol angle the vertical magnetic roll angle will equal the horizontal g
13. ackets are automatically and con tinuously sent out after power is applied Standard autosend binary mode is selected by setting up the system binary constants as follows e Binary constant 08 11 Selects autosend continuously e Binary constant 01 5a Autosend enable e Binary constant 35 10 Inserts a small delay between data packets optional Computer Interface 6 9 Comparison of ASCII and Standard Binary Data Structures Either ASCII or standard binary data transmission transmits the same data contents but the ASCII data transmission uses about 8 times more bytes than the binary transmission The binary data packet is a much more efficient method of sending data In addition binary data is often much easier to parse than ASCII data Table 8 shows the definition of the binary data packet for sensor mode and anglemode Table 8 Binary Data Packets for Sensor and Angle Modes Byte Sensor mode Angle Mode 1 0x1 0x1 02 MX MSB Gravity Toolface ROLL MSB 03 MX LSB Gravity Toolface ROLL LSB 04 AX MSB Magnetic Toolface MAGROLL MSB 05 AX LSB Magnetic Toolface MAGROLL LSB 06 MY MSB Inclination PITCH MSB 07 MY LSB Inclination PITCH LSB 08 AY MSB Total Magnetic Field MAG MSB 09 AY LSB Total Magnetic Field MAG LSB 10 MZ MSB Azimuth HEAD MSB 11 MZ LSB Azimuth HEAD LSB 12 AZ MSB Total Gravity GRAV MSB 13 AZ LSB Total Gravity GRAV LSB 14 Temper
14. ature MSB Temperature TEMP MSB 15 Temperature LSB Temperature TEMP LSB 16 Analog MSB Analog ANA1 MSB Downhole Voltage 17 Analog LSB Analog ANA1 LSB Downhole Voltage 18 ST ST This byte is a status byte without meaning for 547 sensor 19 Checksum Checksum CS 20 EOT MSB 0x7F EOT MSB 0x7F 21 EOT LSB 0xFF EOT LSB OxFF 6 9 1 Sensor Mode Consider the following examples of data transmissions in Sensor Mode from a 547 sensor one in ASCII mode and one in standard binary mode ASCII MX 0 3598 AX 0 2740 MY 0 2490 AY 0 3510 MZ 0 0145 AZ 0 4711 TEMP 21 74 STANDARD BINARY IN SENSOR MODE MY AY F646 F24A MZ AZ 0091 1267 TEMP ANA1 ST CS 087E 0320 80 85 SOT MX AX 10 OEOE OAB4 EOT 7EFEE 547 binary data packets will always start with a header byte 0x10 and end with two bytes Ox7FFF The data is always sent most significant byte MSB first then least significant byte LSB Magnetometer and accelerometer data and temperature data is sent as 16 bit signed integers Magnetometer and accelerometer sensor values MX AX MY AY MZ and AZ can be decoded by first converting to decimal and then dividing by 10 000 For instance in the abovetransmission MX OEOE 3598 10 000 0 3598 Gauss G MY F646 2490 10 000 0 2490 Gauss G AX OAB4 2740 10 000 0 2740 Gee g 12 4 7 VA p gt and User Manual Computer Interface
15. em 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 inputvoltage The 547 communicates with the outside world over a 3 wire serial bidirectional TTL level data link An autosend data mode is included in the 547 software When this mode is active data is repeatedly sent out the system serial port after power is applied The 547 system 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 547 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 have alignment pins and reference surfaces which mate to the 547 alignment pins System calibration can be performed over the two temperature ranges e 0 to 70 C e 0 to 125 C 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 instance for calibration over the interval of 0 to125 C data is read at 25 C increments between 0 and 125 C The data taken at each temperature includes scale of
16. es Azimuth accuracy also degrades as the inclination approaches 90 degrees but this is a coordinate system singularity and does not reflect any underlying error inorientation Table 9 Dip Angle and Azimuth Accuracy Dip angle Azimuth Error deg deg rms 89 5 87 5 2 85 1 80 0 5 70 0 26 67 0 23 60 0 175 0 0 072 6 11 Azimuth Accuracy as a Function of the Inclination Azimuth accuracy becomes poor as one approaches inclination of 0 degrees vertical Refer to Figure 3 for a defini tion of the 547 coordinate definition This is not the result of a real degradation of sensor performance but is an artifact of the coordinate system which is singular at an inclination of O degrees The following graph shows the uncertainties in azimuth as a function of inclination At small inclination angles the error is approximately 1 Inclination while at larger angles error will be dominated more by systematic errors such as imperfect calibration It is assumed for this calculation that the accelerometers are accurate to 0 001g and the magnetometers are accurate to 0 0005 Gauss The dip angle is assumed to be 60 degrees When the system is to be used at small inclination angles the user can use the magnetic roll calculations shown in section 7 4 Calculation of Roll and Magnetic Roll on page 16 as an alternative to the azimuth output 14 Rev 1 1_FEB2011 x Models 547 548 Technical Reference and User Manual Defini
17. fset and sensor alignment data The recorded data is then used to create a look up table for scale offset and align ment corrections This table is downloaded into the 547 internal EEROM memory where it can be accessed by the system internal microprocessor Corrections to the measured sensor data can then be made by the internal micropro cessor system before data is transmitted s 547 548 Technical Reference and User Manua System Specifications 3 System Specifications Table 1 547 548 System Specifications Angular Accuracy Azimuth 1 22 Inclination 0 42 Temperature Range Option 1 0 to 70 C Option 2 0 to 125 C Power Input Voltage Range 5V to 12V 50mA Physical Size 1 00 OD x 10 5 length 25mm x 267mm Weight 1 25 Ibs Shock 1000G 1ms half sine wave Vibration 20G rms 50 500Hz Digital Interfaces Logic Level TTL CMOS Baud Rate User programmable up to 9600 baud Protocol User selectable ASCII or binary Connectors 547 Connector MDM9SH003P ITT Cannon Mating Connector MDM9PHOO3BL ITT Cannon 4 Mechanical Features Figure 1 shows an outline drawing of the 547 System The orientation of the X Y and Z axes of the 547 systemis shown at the bottom of Figure 1 The output polarity sense of the axes is such that a field increase in the direction of the arrows shown in Figure 1 produces an increase in the voltage output for that axis For example if the X magnetom eter is oriented so the X axis arrow points nort
18. gle mode When the 547 is in angle mode the response to a send data command has the following for mat ROLL 35 17825 MAGROLL 198 24032 PITCH 90 14559 MAG 0 43326 HEAD 26 76792 GRAV 1 00101 TEMP 28 026 DA 55 893 where ROLL is gravity roll or toolface PITCH is inclination HEAD is Azimuth MAGROLL is magnetic roll MAG is the total magnetic field GRAV is the total gravity field and DA is the magnetic field dip angle 6 3 Changing Data Output Mode The 547 can be configured to output in raw analog to digital ADC counts sensor values or angles Data output format is determined by the value of binary constant 02 as follows Table 4 Output Data Format Binary 02 Value Output Data Format 0x00 Raw A D Counts Uncalibrated 0x02 Sensor Outputs Calibrated Accel and Mag 0x03 Angular Outputs Roll Inc Azimuth The nomenclature Ox in the above table indicates that the data following the Ox is in hex format 6 4 Changing the Baud Rate The communications baud rate can be changed by using the following sequence 1 Set binary constant 10 according to Table 5 2 Set binary constant 09 to Ox5a 3 Cycle power off and on The following commands illustrate setting the baud rate to 2400 Ol lt CR gt Owcl0b32 lt CR gt Ol lt CR gt Owc09b5a lt CR gt 8 x Rev 1 1_FEB2011 Is a y Applied Physic Models 547 548 Technical Reference and User Manual Computer Interface
19. h in the northern hemisphere then the X axis output voltage will be pos itive If the X axis arrow is pointed down the X axis accelerometer output will be positive Definition of the orientation angles is given in section 7 Definition and Method of Calculation of the Orientation Sensor Angles on page 15 The orientation of the 547 sensor in the drillstring should be such that the X axis is pointed downhole In this orienta tion inclination will be 0 when drilling vertically downhole 5 Electrical Interface Electrical connection to the 547 is made by means of a 9 pin MDM type connector The function of the pins on this con nector is shown in Figure 2 The 547 System powers from a single input voltage ranging from 5V to to 12V The serial communications interface to the 547 is provided by the serial in and serial out lines as shown in Figure 2 An external computer communicates with the 547 on the serial in line and replies from the 547 are transmitted out on the serial out line The serial in and serial out pins operate at TTL CMOS levels and are normally set to operate at 9600 baud with one stop bit and no parity The user can change the baud rate by changing the system byte configuration constants as described in the following section Two communication protocols are available 1 ASCII and 2 BINARY These are both described in section 6 Com puter Interface on page 6 The ASCII protocol is based upon sending ASCII characters
20. le 14 Y Accelerometer Base Scale 15 Z Accelerometer Base Scale Float constants 25 to 34 contain the system alignment coefficients For example float constant 26 contains data on the magnetometer X sensor alignment in the Y direction The 547 sensor is temperature compensated to insure that the accuracy of the sensor is maintained over its intended temperature range The temperature calibration data is stored in the system Flash memory This data can be accessed by using the following commands Ost b lt CR gt Send temperature calibration table in binary format Ost i lt CR gt Send temperature calibration table in integer format Ost f lt CR gt Send temperature calibration table in floating format Computer Interface Models 547 548 Technical Reference and User Manual 6 2 ASCII Communication Mode Communication is initiated when the external computer issues a command such as ASCII characters OSD where 0 is a zero The characters OSD stand for serial number 0 Send Data When this command is issued the 547 will respond with a formatted output similar to the following MX 0 20346 AX 0 07852 MY 0 23165 AY 0 72136 MZ 0 29525 AZ 0 70226 TEMP 28 148 When internal binary constant 02 02 the 547 is in sensor output mode and the above numbers represent the magne tometer X Y and Z sensor outputs in Gauss G and the accelerometer outputs in Gees g When binary byte 02 03 the 547 is in an
21. on page 9 Table 6 Autosend Modes on page 9 Table 7 Output Data Averaging and Filtering on page 9 Table 8 Binary Data Packets for Sensor and Angle Modes on page 12 Table 9 Dip Angle and Azimuth Accuracy on page 14 Figure 1 547 548 Micro Orientation Sensor Outline Drawing on page 18 Figure 2 Connection Diagram for the 547 on page 19 Figure 3 Coordinate System of 547 548 on page 20 Rev 1 1_FEB2011 ae cal Reference and User Manual Introduction 1 Introduction This manual describes the model 547 Directional Sensor This system is designed to enable high accuracy measure ment of the inclination roll or toolface and azimuth orientation angles in borehole environments 2 Description of the Equipment The model 547 Directional 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 547 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 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 547 syst
22. onstant 23 Averages n Averaging Times sec 0 1 0 2 2 0 6 4 4 1 32 8 8 2 64 10 16 5 28 20 32 10 62 40 64 21 30 The average time in the above table is approximately the time for the output to come within 37 of the final value Rev 1 1_FEB2011 9 M Computer Interface Models 547 548 Technical Reference and User Manual The above table assumes that the system analog to digital A to D converter low pass filter is set to the default of 30 Hz For higher or lower filter settings the average time will proportionately higher or lower For example if the A to D fil ter is set to 100 Hz then the average time will be decreased by a factor of 3 3 so that for 64 averages the average time will be 6 45 seconds Each data output of the 547 is arunning average of the previous n data acquisitions where n is the value of binary con stant 23 When a new data point is acquired a new average is computed by dropping the oldest data point from the average and adding the new data point The maximum average is 64 samples This average feature is useful for high vibration environments when the user knows the attitude is changing slowly but vibration produces a large amount of noise in the 547 output The A to D low pass filter 3 dB frequency can be set and displayed by use of the following set of commands To show current setting in Hz Osf lt CR gt Toset the frequency O01 lt CR gt Owf xx lt CR where
23. ravitational roll angle 20 alk Wd x Wy Rev 1 1_FEB2011
24. t Last lt lt lt lt lt SOT gt lt Rol1l gt lt MagRoll gt lt Inclination gt lt TotMag gt lt Head gt lt TotGrav gt lt MT gt lt V gt lt Status gt lt Data Check Sum gt lt END gt 8b 16b 16b 16b 16b 16b 16b 16b 16b 8b 8b 16b All Data is Sent most significant byte first e lt END gt 0x7FFF should be unique in the data stream e lt SOT gt 16 Decimal or 10 Hex e lt Status gt a constant 0x80 without meaning for 547 sensors e lt DATA CHECK SUM gt The lower 8 bits of the sum of all the bytes in the data area excluding lt SOT gt and lt END gt All angles are encoded by multiplying the angle by 10 e g 123 56 1235 6 e lt TolMag gt Total magnetic field is in a two byte signed integer format encoded as the float value times10000 For example 0 3929 is encoded as 3929 e lt TolGrav gt Total Gravity is in a two byte signed integer format encoded as the float value times10000 For example 1 0047 is encoded as 10047 e lt MT gt The Temperature is in a two byte signed integer format encoded as the float value times 100 123 45 12345 e lt V gt Downhole power voltage is in a two byte signed integer format encoded as the float value times 100 8 457 84 57 6 8 Autosend Binary Communication Mode Standard binary protocol results in the transmission of data packets with the same structure as that described above for the response to binary command 128 However when in autosend mode data p
25. t Status gt lt DATA CHECK SUM gt lt END gt 8b 16b 16b 16b 16b 16b 16b 16b 16b 8b 8b 16b All Data is Sent most significant byte first 10 Rev 1 1_FEB2011 x 4 Models 547 548 Technical Reference and User Manual Computer Interface e lt END gt 0x7FFF should be unique in the data stream e lt SOT gt 16Decimal or 10 Hex e lt Status gt a constant 0x80 without meaning for 547 sensors e lt DATA CHECK SUMS gt The lower 8 bits of the sum of all the bytes in the data area excluding lt SOT gt and lt END gt e lt MX gt lt MY gt lt MZ gt The Magnetometer data are in a two byte signed integer format encoded as the float value times10000 for example 0 2345 is encoded as 2345 e lt AX gt lt AY gt lt AZ gt The Accelerometer data are in a two byte signed integer format encoded as the floatvalue times10000 for example 0 2345 is encoded as 2345 e lt MT gt The Temperature is in a two byte signed integer format encoded as the float value times 100 123 45 12345 e lt V gt Downhole power voltage is in a two byte signed integer format encoded as the float value times 100 8 4575 845 75 Command lt 131 gt Sends All Angle Data in an encoded Binary Format The data is returned as lt lt lt lt Sent First lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt Sen
26. tion and Method of Calculation of the Orientation Azimuth Error degrees Errorin degrees 0 T T T 0 5 10 15 20 Inclination in degrees 7 Definition and Method of Calculation of the Orientation Sensor Angles This section provides a definition of the system orientation angles and describes how to calculate them from acceler ometer and magnetometer sensor outputs 7 1 Sensor Based Coordinate System The coordinate system of the 547 is defined in Figure 3 Coordinate System of 547 548 on page 20 The accelerom eter and magnetometer coordinate systems are both aligned with the physical package coordinate system Forthe magnetometer sensors a positive output voltage will result if the sensor is pointed north For the accelerometers a positive voltage will result if the sensors are pointeddown 7 2 Definition of Orientation Angles e Azimuth is defined as the angle measured from magnetic north clockwise from above to the projection of the X axis on the horizontal plane e Inclination is the angle that the X axis makes with the down direction and is 0 when the X axis is down and 90 when the X axis is horizontal e Roll or gravity tool face is defined as the angle of counterclockwise rotation about the X axis looking in the positive X axis direction required to zero the Y axis accelerometer output and position the Z axis accelerometer so that its output polarity is positive e Magnetic roll or
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