Digital Compass Module User`s Guide
Contents
1. gt for 55 Hz BA6 8 30 lt CR gt lt lIf gt for 110 Hz ZBA6 0A CR If Zm hh CR lf BA7 nn hh lt CR gt lt lf gt BA7 0B lt CR gt lt lIf gt N hh lt CR gt lt lf gt FA0 6 1 23 lt CR gt lt lf gt FA0 6 0 22 lt CR gt lt lf gt FA0 6 10 lt CR gt lt If gt 1 31 lt CR gt lt lf gt 0 30 lt CR gt lt lf gt BA9 ddd hh lt CR gt lt lf gt ddd Set Reset interval in seconds 9 05 T hh lt CR gt lt lf gt Mag units factor Conversion factor for normalized Mag readings to mGauss 900240 Rev B 3 01 page 16 Query Response MagX offset nnnn in counts Query Response MagY offset nnnn in counts Query Response MagZ offset nnnn in counts Query Response Mag high alarm Query Response Mag high warn Query Response Mag low warn Query Response Mag low alarm Hard iron offset along north south axis in magnetometer counts Allows the user to input a value N Hard Iron offset in counts Hard iron offset along east west axis in magnetometer counts Allows the user to input a value N Hard offset Hard iron offset along vertical axis in magnetometer counts Allows the user to input a value N Hard offset Sets the magnetometer Over Range Alarm level in magnetometer counts Issues an Alarm condition P in the magnetic field status of the HPR output sentence when the total mag field value Mag T exceeds t2. 10 CHECKSUM FILED 13 WARNING AND ALARM 5 5 2 12 144 13 CONFIGURATION PARAMETERS eee ee eene nnne nennen es 14 GENERAL CONFIGURATION 65 0 eee 15 MEASUREMENT PARAMETERS 16 IE a UN E O OA aI 19 DESCRIPTION HARDWARE INTERRUPT 5 21 ALGORITHM FOR THE NON LINEAR HEADING FILTER 21 PHYSICAL DIMENSIONG ccccssccessccessecssececsesecsesessecersscecsscecsseecsucessuscusscsessesusassucansessnsesaneeeeveess 22 900240 Rev B 3 01 page iii 1 0 INTRODUCTION Thank you for purchasing Honeywell s HMR3000 Digital Compass Module The HMR3000 uses Honeywell magnetic sensors with proven MR technology and a two axis tilt sensor to bring you the heading information This electronically gimbaled compass gives accurate heading even when the compass is tilted up to 40 degrees The HMR3000 is reliable and rugged since it does not contain any moving components and uses all surface mountable components This low power small device is housed in a non magnetic metallic enclosure that can be easily installed on any platform The HMR3000 is easy to use and extremely versatile It allows the user to configur
3. orientation and location of the compass A re calibration is necessary after a relocation of the compass or if the platform has changed its magnetic character Compass calibration is performed by following a calibration procedure specified by the manufacturer During this procedure the compass collects data required for the compensation algorithms The goal of the calibration procedure is to sample the magnetic field components for many possible orientations of the host system Rotating the host system through 360 degrees or driving in a circle in the case of a vehicle will enable the compass to sample its magnetic environment The HMR3000 can be calibrated by either using the built in calibration method or by using the PC Demo Interface software program The calibration procedure for both these methods is the same Built in Calibration Method This method uses an iterative procedure to calculate the hard iron offsets In most situations 275 iterations would produce good results The calibration procedure has to continue until this iteration count is reached To put the HMR3000 into calibration mode issue F33 4 0 5 1 lt CR gt lt lf gt Slowly rotate the host system through a full circle in a gentle motion while changing roll and pitch as much as the host will allow Generally this procedure will take over two minutes Check the iteration count by issuing 26 31 lt gt lt 1 HMR3000 will reply with a thnnn hh CR lf message wher
4. 1 include m 0 exclude Include MAGZ in XDR sentence 1 include m 0 exclude Include MAGT in XDR sentence 1 include m 0 exclude FA1 0 0 25 lt CR gt lt lf gt FA1 0 1 24 lt CR gt lt lf gt FA1 0 2 17 lt CR gt lt lIf gt m hh lt CR gt lt lf gt FA1 1 0 24 lt CR gt lt lf gt FA1 1 1 25 lt CR gt lt lf gt ZFAI 1 I6 CR lf m hh lt CR gt lt lf gt FA1 2 0 27 lt CR gt lt lf gt FA1 2 1 26 lt CR gt lt lf gt FA1 2 15 lt CR gt lt lIf gt m hh lt CR gt lt lf gt FA1 3 0 26 lt CR gt lt lf gt FA1 3 1 27 lt CR gt lt lf gt 1 32 14 lt CR gt lt lIf gt m hh lt CR gt lt lf gt FA1 4 0 21 lt CR gt lt lf gt FA1 4 1 20 lt CR gt lt lf gt FA1 4 13 lt CR gt lt lIf gt m hh lt CR gt lt lf gt FA1 5 0 20 lt CR gt lt lf gt FA1 5 1 21 lt CR gt lt lf gt FAI 5 12 lt CR gt lt lIf gt m hh lt CR gt lt lIf gt Table 8 Serial I O Parameters In the current configuration software when the baud rate is changed the new rate will not take effect until a Force Reset command is issued or until the unit is powered off then on When any output sentence rate is changed the current interval will expire before the new rate takes effect Index Rate Index Rate Index Index Rate 413 Table 9 Index values corresponding to output message rate 900240 Rev 3 01 page 20 5 0 DESCRIPTION OF HARDW
5. PC has slow graphic capability or if other applications are running in the background 27 Getting data from HMR3000 Once the power and interface cables are connected and the software installed in your computer begin to acquire compass data from HMR3000 Launch PC Demo Interface by double clicking the program icon in PC Demo Interface window Select the appropriate COM port and choose 19200 as the baud rate factory setting Message box identifying the Firmware Version should appear This message indicates a successful installation and interface connection Activate Tune Parameters in the PC Demo Interface from the Parameters menu or use the Tune button The compass is in RUN Continuous mode with NO messages coming out Message rates for all the output sentences are set to 0 at the factory Set the message rate of HPR sentence to 825 Tune Page Serial Output Now the compass should output heading pitch and roll data at 825 sentences min rate Activate Display View Interface or Display Monitor NMEA Sentences to see the output Diagnostics View Log is another option to inspect compass data Make sure the Log all messages logging page in Diagnostics Options menu option is activated 900240 Rev B 3 01 page 3 Note A non zero HPR message rate should be chosen for View Interface to be active The compass rose showing Heading ant Tilt information will require a fast processor Pentium to respond fast enough with the com
6. assumed to be zero otherwise it is added to measured heading and variation to express true heading of compass board Eg In Degree Mode HCHDT 86 2 T 15 900240 Rev B 3 01 page 10 HCHDT 271 1 T 2C HCHDT 0 9 T 20 Mil Mode not allowed by NMEA standard XDR Transducer Measurements HCXDR A x x D PITCH A x x D ROLL G x x MAGX G x x MAGY G x x MAGZ G x x MAGT hh lt cr gt lt lf gt Each of the six possible measurements pitch roll and magnetic x y z and total can be individually included in or excluded from the message see XDR has parameters See NMEA 0183 for a detailed description of the Type Data Units ID field encoding The Data field of an included measurement will be null if its contents cannot be determined due to saturated measurements Only units of degrees are allowed by NMEA for pitch and roll measurements Magnetic measurements are transmitted in engineering units milli Gauss determined by a tunable conversion factor MAGX aligns with the compass board north south axis and MAGZ is perpendicular to the plane of the compass board MAGT is the total magnetic field strength determined by calculating the square root of the sum of the squares of MAGY and MAGZ Eg In Degree Mode HCXDR A 0 8 D PITCH A 0 8 D ROLL G 122 MAGX G 1838 MAGY G 667 MAGZ G 1959 MAGT 11 In Mil Mode HCXDR A 3 D PITCH A 14 D ROLL G 1090 MAGX G 5823 MAGY G 20 MAGZ G 5924 MAGT 2
7. computer is not servicing the graphical interface fast enough Close other application or try a fast computer Pentium D Log file does not update Compass is in Stop mode See above Log messages is tuned off Click Log all messages in Diagnostics Options Logging tab Log does not display the recent messages Click off the Always show most recent entry box in Diagnostics V Options V Logging tab E Heading display turns blank and Red Compass is in a high magnetic field region Move HMR3000 away from this region or lower the magnetometer gain see HMR3000 User s Guide for details 900240 3 01 page 23 How to set the Baud Rate Through the PC Demo Interface Connect the device and run PC Demo 2 Goto Tune Parameters Serial Output page through the main menu of the program 3 Select the baud rate 4 Power down the device 5 Power up the device and communicate with the new baud rate Through Direct Commands 1 Setup normal communications with the current baud rate 2 Issue the commands see Section 4 4 of the User s Guide and Baud Rate 3 Power down the device 4 Power up the device and communicate with the new baud rate 900240 Rev 3 01 page 24
8. correct checksum value Response to a Request for output sentence is the appropriate sentence 2 Response to parameter input will be 0000 21 to indicate the command and the parameter was accepted H M l 900240 Rev 3 01 page 9 38 Output There are six possible NMEA messages three standard and three proprietary that can be automatically sent from the HMR3000 in Continuous Mode by selecting their Update Rates Additionally there is a seventh non conforming ASCII display message that can also be sent The ASCII display message is not expected to commingle with the other six NMEA messages It is intended for simpler systems where the HMR3000 is connected to a numerical readout device instead of a host processor The update rate for each message can be set independently to one of the following 0 1 2 3 6 12 20 30 60 120 180 300 413 600 825 or 1200 sentences per minute If the output channel due to its programmed baud rate cannot accommodate the total number of sentences selected then the channel will operate at full speed and highest priority will be given to responses to input followed by sentences with update rates from lowest to highest Fairness will be implemented in the priority scheme so that each sentence ready for output is transmitted at least once before higher priority sentences are repeated 3 9 Query for NMEA Se
9. gt 0 30 lt CR gt lt lf gt FA0 5 1 20 lt CR gt lt lf gt FA0 5 0 21 lt CR gt lt lf gt FA0 5 13 lt CR gt lt lIf gt 1 31 lt CR gt lt lf gt 0 30 lt CR gt lt lf gt TE2 nnn n hh lt CR gt lt lf gt degree mode hh is the checksum value Query IE2 01 lt CR gt lt lIf gt Response Variation angle Deviation angle nnn n hh lt CR gt lt lf gt Sets the Variation angle to value nnn n in E4 nnn n hh lt CR gt lt lf gt degree mode hh is the checksum value Query IE4 07 lt CR gt lt If gt nnn n hh lt CR gt lt lf gt Response Variation angle Table 6 General Configuration Parameters 900240 Rev B 3 01 page 15 43 Measurement Parameters Parameters in this section affect the measurement functions of the compass board Mag sample rate is a key setting that affects both continuous and strobe mode measurements In continuous mode either 1 2 4 or 8 magnetometer measurements are averaged per tilt measurement depending on the Mag sample rate setting In strobe mode measurements are suspended until an NMEA query command is received When this occurs Mag sample rate determines how many magnetometer readings are collected per tilt measurement as above and Strobe mode count determines the number of readings to be averaged before returning the resulting requested sentence A Strobe mode count of zero will result in 256 samples being averaged which will require 18 6 seconds betw
10. ARE INTERRUPT PINS Detail description of the functionality of the Cont Reset Operate Calibrate Ready Sleep Run Stop switches The order of precedence for operation of the switch inputs is as follows highest first 1 Setting Cont Reset low unconditionally holds the processor in its reset state No other functions be performed until the switch is returned to the Continue position 2 Setting Operate Calibrate low Calibrate forces the processor into Calibrate mode The Run Stop and Ready Sleep switches are ignored in this mode When the switch is set to the Operate position the unit can be in either mode depending on the Select Mode command bit that can be changed via the serial interface The Select Mode command bit is initialized to the Operate state on power up 3 Setting Ready Sleep low while the unit is not in Calibrate mode forces the unit into a low power state with measurements and outputs suspended and with serial inputs ignored This switch must be returned to the Ready position before a host can send a serial command When momentarily placed in the Ready position the processor will run a complete measurement and output cycle if in Run mode before suspending operation Mechanical switch bounce on this input can be tolerated in the firmware 4 Setting Run Stop low stops any output in progress within one character time and prevents further output When the switch is in the Run position the
11. B The following describe the proprietary sentences in detail HPR Heading Pitch amp Roll PTNTHPR x x a x x a x x a hh lt cr gt lt lf gt This sentence combines HMR3000 s three significant measurements with useful status information Data fields represent in order heading magnetic field status pitch pitch status roll and roll status Heading pitch and roll measurements are presented in degrees or mils depending on the setting in EEPROM The heading measurement is corrected for deviation and variation when these factors are programmed in the EEPROM Eg In Degree Mode PTNTHPR 85 9 N 0 9 N 0 8 N 2C PTNTHPR 7 4 N 4 2 N 2 0 N 33 PTNTHPR 354 9 N 5 2 N 0 2 N 3A In Mil Mode PTNTHPR 90 N 29 N 15 N 1C Status fields can contain one of six letter indicators L low alarm M low warning N normal O high warning or P high alarm C Tuning analog circuit If any of the three status fields indicates alarm then the heading field will be null as well as the corresponding measurement field Thresholds for alarm and warning levels can be changed in the EEPROM RCD Compass Data PTNTRCD x x x x X X X X X X X X Xx X x x x x hh er 1f 900240 Rev B 3 01 page 11 This sentence provides raw tilt and magnetic measurements for diagnostic use Contents of each field represent A D readings for in order TiltAp TiltAm TiltBp TiltBm MagA MagB MagC MagAsr MagBsr MagCsr values represent the actua
12. Honeywell HMR3000 Digital Compass Module User s Guide Packing List HMR3000 D00 232 HMR3000 RS 232 Circuit Card Demo Software and Users Manual CD Rom H MR3000 D00 485 HMR3000 RS 485 Circuit Card Users Manual CD Rom HMR3000 D21 232 Housed Compass Module RS232 Demo Software Disk 1 and 2 Users Manual CD Rom Housed Compass Module RS485 Users Manual CD Rom HMR3000 Demo Kit Housed Compass Module RS232 Demo Software Disk 1 and 2 User s Manual CD Rom Power supply and interface cable PC Demo Software Version 2 01 or higher Parameter or Condition Default Setting Baud Rate 19200 Operation Mode Output Sentences filter 1 time constant Heading filter L value 0 Heading filter S value 0 I 900240 Rev B 3 01 pagei How to Set up HMR3000 Demo Unit 2 3 Connect the interface cable between the HMR3000 and COM port of a PC Select the line voltage input 110 220 V turn the voltage selector to 9 V dc mark and plug in the adapter to an electrical outlet Install PC Demo Interface software on the PC by running Setup exe from CD Rom In Windows 95 or NT click start then Run and browse CD Rom to find Setup exe Version 2 01 or higher Double click on PC Demo Interface icon 5 Select the correct COM port and 19200 baud rate COM port is usually COMI Click the musical note button F Go to Serial Output tab and change the m
13. Index value I for HPR rate Same as previous for RCD sentence I Index value Returns the Index value I for RCD rate Same as previous for CCD sentence I Index value Returns the Index value I for CCD rate Same as previous for ASCII display sentence I Index value Returns the Index value I for ASCII rate 900240 Rev B 3 01 ZBA4H 40 CR lf 1 hh lt CR gt lt lf gt BAA I hh lt CR gt lt lf gt BAA 7D lt CR gt lt lIf gt 1 hh lt CR gt lt lf gt BAB I hh lt CR gt lt lf gt ZBAB 7E CR If 1 hh lt CR gt lt lf gt BAC I hh lt CR gt lt lf gt ZBAC 7F CR lf 1 hh lt CR gt lt lf gt BAD I hh lt CR gt lt lf gt ZBAD 78 CR If I hh lt CR gt lt lf gt BAE I hh lt CR gt lt lf gt BAE 79 lt CR gt lt If gt 1 hh lt CR gt lt lf gt BAF I hh lt CR gt lt lf gt ZBAF 7A CR If 1 hh lt CR gt lt lf gt BBO I hh lt CR gt lt lf gt BBO 0F lt CR gt lt lIf gt 1 hh lt CR gt lt lf gt page 19 XDR has Pitch Query Response XDR has Roll Query Response XDR has MagX Query Response XDR has MagY Query Response XDR has MagZ Query Response XDR has MagT Query Response Include or exclude PITCH in XDR sentence Exclude Include m 1 include m 0 exclude Include ROLL in XDR sentence m 1 include m 0 exclude Include XDR sentence m 1 include m 0 exclude Include MAGY in XDR sentence
14. Option The HMR3000 communicates with an external host via RS232 or RS485 electrical standard through simple ASCII character command strings host computer can direct operation of HMR300 with these commands With the RS232 option a user friendly graphical interface is provided to direct operation of the compass RS232 Option The Compass Module is supplied with PC Demo Interface a software program that allows the user to configure HMR3000 with the RS232 option This program is for IBM PC compatible machines running MS Windows 3 11 Windows 95 or Windows 97 PC Demo Interface allows the user to communicate between the HMR3000 and the PC This is used to configure the HMR3000 receive compass outputs and to log and capture compass messages PC Demo also demonstrates the input output options available and is a great tool to learn about HMR3000 2 6 Install PC Demo Interface Enclosed is a CD Rom containing PC demo Software is included Run Setup exe from CD Rom The installation software will guide through the process Computer Requirements Minimum PC 486 33 MHz Windows 3 1 Windows 95 or NT Operating System VGA 2 Mb disk space more for log file and captured data RS 232 serial port Recommended P5 120 MHz Windows 3 1 Windows 95 or NT Operating System SVGA 1024 x 768 Microsoft Excel 5 0 or greater for capture and export of data if desired Note The Graphical output of the HMR3000 on PC Demo software may become sluggish if the
15. Query Response magnetic field status of the HPR output sentence when the total mag field value Mag T falls below the parameter setting Sets the Over range alarm level for pitch and roll Issues an Alarm condition P in the Pitch or Roll status fields of the HPR output sentence when either pitch or roll output exceeds the parameter setting In degrees Pitch Roll alarm level Sets the Over range warn level for pitch and roll Issues an warn condition O in the Pitch or Roll status fields of the HPR output sentence when either pitch or roll output exceeds the parameter setting In degrees Sets the filter constant Normalized time constant for IIR filter 1 T 0 disable T 1 72 msec T 255 18 4 sec Normalized time constant T Sets the parameter S for the non linear Heading filter Smoothing amount see algorithm in text 0 disable Max 0 999985 m S 65535 m S 65535 Sets the parameter L for the non linear Heading filter Difference knee in mils see algorithm in text 0 disable 1 1 mil max 255 mils Smoothing factor L ZWBC 69 CR lf nnnnn hh lt CR gt lt lf gt WE6 nn n hh lt CR gt lt lf gt ZWE6 IB CR lf nn n hh lt CR gt lt lf gt WE8 nn n hh lt CR gt lt lf gt ZWES8 15 CR If nn n hh lt CR gt lt lf gt BA2 T hh lt CR gt lt lf gt ZBA2 0E CR If T hh lt CR gt lt lf gt WB2 m hh lt CR gt lt lf gt WB2 18 lt CR g
16. e In such case the Z offset will appear in red and the corresponding check box empty User has the option to accept this value by checking the box Z Reference Method In applications which changing the tilt of the host is not possible an approximate value of the Zoffset can be found by using the Z Reference Method This method directly compares the Z component of the earth s magnetic field in an undisturbed location to that of the host This procedure involves two steps Step 1 Collect Z reference value near the calibration site away from large metal objects that will distort the earth s field by Activating Diagnostics Capture Clear Z Reference Hit Read Data Hold the compass approximately level Hit Stop after capturing 10 20 readings and hit Apply to save the new Z Reference value the EEPROM of HMR3000 Step2 Install the compass on the host and follow the normal 3D Calibration descrbed above Mag Z offset will be computed from the Z Reference method as well as the normal method and the most appropriate value is indicated by a cross mark against the value Goodness of Calibration At the end of each calibration PC Demo calculates and reports a variation number the lower the number the better the calibration The compass should be relocated if the variation number is greater than 40 3 0 OPERATION OF THE HMR3000 IN DETAIL 31 GENERAL The HMR3000 consists of three magnetoresistive magnetic sensors and a liquid filled t
17. e compass output to include any combination of six NMEA standard messages and to change measurement parameters for the magnetometer to suit the application The sophisticated auto compass calibration routines will correct for the magnetic effects of the platform Wide dynamic range of the magnetometer 1 or 100 uT allows the HMR3000 to be useful in applications with large local magnetic fields 2 0 GETTING TO KNOW THE HMR3000 PRODUCT 21 Identifying the product HMR3000 Compass module comes in three different options 1 Circuit board with RS 232 or RS485 electrical interface 2 Housed Compass Module with RS232 or RS485 electrical interface 3 Demonstration Kit RS232 only The electrical interface of the compass module is clearly marked on the circuit board in option 1 and on the product label in option 2 Option 3 only comes with RS232 electrical interface 22 Settingup Interface and power cables Interface and power supply should be included in the Demonstration Kit see Electrical Connections in Section 2 4 For other HMR3000 product options a cable having a standard 9 pin D shell female connector should be wired according to the pin out defined below Power should only be connected to either pin 9 or pin 8 It is sufficient to connect the pins listed in Table 1 for most applications However pins 1 4 6 and 7 serve specific purposes in the operation of HMR3000 and should be kept open high logic state in normal operation s
18. e nnnn is the value of the iteration count If this value is less than 275 continue with the calibration procedure until that number reaches 275 At the end of this procedure issue a command to save the results in the EEPROM F2FE 2 1 67 lt CR gt lt lf gt Put the unit back into Operate mode issue F33 4 1 50 lt CR gt lt lIf gt 900240 Rev 3 01 page 5 This method works when the hard iron field is small PC Demo Interface Software Method 3D Calibration This method is recommended when the hard iron field is large The PC demo interface will collect magnetic vector information and analyze to find the hard iron offsets Launch PC Demo Interface Ver 2 02 or higher In PC Demo go to Diagnostics menu and to Perform 3D Calibration menu In Hard Iron page activate Read Data You should see the Total Valid Readings t of data points collected go up If not check the following First quit the Cal page Go to Diagnostics V Options 1 Calibration Select Real Time Data from Unit by clicking that option Slowly rotate the platform through a full circle in a gentle motion while changing roll and pitch as much as the platform will allow Generally this procedure will take over two minutes At the end of this procedure hit Stop Once the computation is complete hit Apply to put the Hard Iron offsets into the unit If sufficient tilt change were not encountered during the calibration procedure then the calculated Zoffset value may not be reliabl
19. ee Table 2 for complete pin out description See Figure 1 for suggested cabling diagram for connection between HMR3000 and COM port of a computer IBM D Out Pin TxD A 2 RS 232 transmit out RS 485 transmit receive signal RxD B 5 232 receive RS 485 transmit receive return GND In In 3 Power and signal common 6 15V In 9 Unregulated power input Regulated power input Table 1 Pin assignment for typical operation of HMR3000 See Table 2 for complete description Caution Do NOT exceed 5 5V at regulated power input pin 8 Higher voltages will damage components 900240 Rev 3 01 pagel 23 HMR3000 Connection Diagram Computer RS232 to HMR3000 Unregulated Supply R 232 computer pins HMR 3000 PINS ac adapter Regulated Supply RS 232 computer pins HMR 3000 pins Regulated voltage source Figure 1 Interface and power connections for RS232 devices 24 Electrical Connections Connect the cable between HMR3000 and a COM port of the IBM compatible computer Supply power to HMR3000 6 15V at the unregulated power input or 5V regulated If you purchased HMR3000 Demonstration Kit use the power and interface cable to connect between HMR3000 and your computer s COM port Make sure the line voltage selection 110 or 220V in the adapter is appropriate and that 6 Vdc or higher output voltage 15V is selected 900240 Rev 3 01 page 2 25 Communication R S232
20. een the end of the query request and the start of the output sentence The Mag units factor setting is used to convert normalized magnetometer readings to milliGauss for output in and CCD messages The intent is to provide outputs with approximate field strength units so that the magnitude of the numbers make sense Command Syntax Mag sample rate Query Response Strobe Mode Count Query Response Set Reset Query Response Set Reset interval ddd Query Response Magnetometer sampling rate 13 75 27 5 55 110 Hz This parameter will determine the number of magnetometer readings averaged per heading output Set to 13 75 Hz for low power consumption m 1 for 13 75 m 2 for 27 5 m 4 for 55 m 8 for 110 Hz Number of heading measurements to be average before issuing an output in Strobe Mode operation 0 to 255 N Number of reading to average 0 to 255 Controls the magnetometer Set Reset operation Set Reset ON Set Reset at 13 75 Hz Set Reset OFF Time interval between magnetometer Set Reset calibrations in seconds 0 disable 255 4 min 15 sec max Use long time interval to reduce power consumption Use continuous or short time intervals for high repeatability This parameter applies only when Set Reset is turned OFF Time between Set Reset in Seconds BA6 1 39 lt CR gt lt If gt for 13 75 Hz 2 3 lt gt lt 1 for 27 5 Hz 6 4 3 lt gt lt
21. eral page 0 180 deg The angle between compass forward direction 0 3200 mils and that of the platform Add deviation to get platform heading Table 2 Parameters attached routinely or at installation 2 10 Communication RS485 Option Operation and configuration of a HMR3000 with RS485 interface is directed through direct command input from the host computer microprocessor No graphical interface is supplied with this product option See Configuration Parameters section for details and Figure 2 for computer connections RS 232 to RS 485 B amp B Electronics 485TBLED SD Ci l i Echo Off Shield TD RS 485 RD GD Gnd 12VDC DB9 socket connector 900240 Rev B 3 01 page 4 Figure 2 RS485 to Computer Connection The HMR3000 Compass module s RS 485 interface is half duplex i e transmit and receive circuits share the same physical pair of wires The HMR3000 must disable its transmitter to allow characters to be received from a host system If the unit is operating in Run mode i e generating repetitive output then the Run Stop pin pin 6 should be forced low before the host attempts to transmit a command See details in Description of hardware interrupt section 2 11 Installation To get optimum performance when installing HMR3000 follow the guidelines listed below for your vehicle or platform Location Install the HMR3000 as far as possible from any source generating a magnetic field and far from ferrous
22. essage rate on HPR sentence to 825 Click on the display button gg Note You should have received PC Demo Interface Ver 2 01 or higher If you have an older version please update to the latest version Please call Honeywell customer services at 612 954 2888 if you need this newer version of software Computer Requirements Minimum PC 486 33MHz Windows 3 1 Windows 95 or NT Operating System VGA 2 Mb disk space more for log file and captured data RS 232 serial port Recommended P5 120MHz Windows 3 1 Windows 95 or NT Operating System SVGA 1024 x 768 Microsoft Excel 5 0 or greater for capture and export of data if desired Note The Graphical output of the HMR3000 on PC Demo software may become sluggish if the PC has slow graphic capability or if other applications are running in the background 900240 Rev B 3 01 page ii 3 11 3 12 4 0 42 4 3 44 5 0 6 0 7 0 Table of Contents INTRODUCTION seme DOE n PUR 1 GETTING TO KNOW HMR3000 1 IDENTIFYING THE 00 2 0 ene enhn see sheer sn sese ee 1 SETTING UP eee 1 HMR3000 CONNECTION DIAGRAM COMPUTER RS232 TO 000 2 ELECTRICAL CONNECTIONS reet ee era o coto oe eroe o pete 2 COMMUNICATION RS232 0 00 0 ee
23. figuration parameters that can be set using HMR3000 s configuration software 4 1 OPERATIONAL Using the serial protocol described in the previous section an external host can direct operation of the HMR3000 with the following commands Command Syntax FA0 3 1 26 lt CR gt lt lf gt Start Compass measurements Stop 0 Stop Strobe mode FA0 3 0 27 lt CR gt lt lf gt Stop Compass measurements Query query for Run Stop status FA0 3 15 lt CR gt lt lf gt Respond with status Response Run 1 31 lt CR gt lt lf gt Stop 0 30 lt CR gt lt If gt Force Reset Perform power up reset F33 6 1 52 lt CR gt lt lIf gt sequence Initialize Filters Reset filter set after F33 2 1 56 changing TC1 Table 5 Basic operational parameters of the HMR3000 ESSE iJ 900240 Rev B 3 01 page 14 42 General Configuration Parameters The parameters in this section affect the general operation of the compass board Command Syntax FA0 4 1 21 lt CR gt lt lf gt Degrees Mils Query Response Decimal Hex Query Response Deviation angle Sets the units for heading pitch and roll 1 degrees 0 0 to 359 9 0 mils 0 to 6399 Degrees mils 9 160 Sets the default number base for data I O 1 decimal 0 hexadecimal query for I O number base Decimal Hexadecimal Sets the Deviation angle to value nnn n in FA0 4 0 20 lt CR gt lt lf gt FA0 4 12 lt CR gt lt lIf gt 1 31 lt CR gt lt lf
24. hard iron MagT Total magnetic field strength Heading calculated heading based on the magnetometer and inclinometer data in this sentence Presented in degrees or mils depending on the setting in EEPROM This field will be null if the heading cannot be calculated Eg In Degree Mode PTNTCCD 522 472 109 1841 677 1964 86 3 44 In Mil Mode PTNTCCD 25187 351 3909 1899 4394 6180 1838 58 ASCII Message The special ASCII display message normally consists of a string of 4 digits that represent the heading in degrees and tenths followed by a terminating carriage return character Heading is corrected for deviation and variation when these factors are programmed in the EEPROM When the heading cannot be transmitted due to a magnetometer or tilt signal out of range then 4 minus signs are transmitted instead Eg In Degree Mode 86 1 900240 Rev B 3 01 page 12 3 11 Checksum Filed This absolute value is calculated by exclusive OR operation on 8 data bits ASCII code no start or stop bits of each character the message between but excluding and or between and characters The hexadecimal value of the most significant and the least significant 4 bits of the result is converted to two ASCII characters 0 9 A F for transmission The most significant character is transmitted first 3 12 Warning and Alarm Settings Tilt and magnetometer limits can be programmed in to the EERROM to generate Warning and A
25. he parameter setting Sets the magnetometer Over Range Warning level in magnetometer counts Issues a Warning condition O in the magnetic field status of the HPR output sentence when the total mag field value Mag T exceeds the parameter setting Sets the magnetometer Under range warning level in magnetometer counts Issues a Warning condition M in the magnetic field status of the HPR output sentence when the total mag field value Mag T falls below the parameter setting Sets the magnetometer Under range alarm level in magnetometer counts Issues an Alarm condition L in the 900240 Rev B 3 01 ZWB4 I1E CR lf 1C4 nnnn hh lt CR gt lt lf gt IC4 01 lt CR gt lt If gt N hh lt CR gt lt lf gt 1C6 nnnn hh lt CR gt lt lf gt IC6 03 lt CR gt lt If gt N hh lt CR gt lt lf gt IC8 nnnn hh lt CR gt lt lf gt ZIC8 0D CR lf N hh CR If W B6 nnnn hh lt CR gt lt If gt ZWB6 1C CR lf nnnnn hh lt CR gt lt lf gt WB8 nnnn hh lt CR gt lt lf gt ZWB8 12 CR If nnnnn hh lt CR gt lt lf gt WBA nnnn hh lt CR gt lt lf gt ZWBA 6B CR lf nnnnn hh lt CR gt lt lf gt WBC nnnn hh lt CR gt lt If gt page 17 Query Response Pitch roll alarm nn n Query Response Pitch roll warn nn n Query Response TCI time constant T Query Response S smoothing factor S Query Response L smoothing factor L
26. l A D readings from the most recent conversions except that tilt readings are adjusted if low gain was used for the conversion sr values represent the sum of the most recent calibration Set and Reset pulse measurements for each sensor There are never any null fields in this sentence Eg In Degree Mode PTNTRCD 1509 1551 1548 1553 15199 16146 17772 17055 16176 17059 42 In Mil Mode PTNTRCD 1435 1512 1497 1453 16776 14066 9477 17403 16073 17225 7F CCD Conditioned Compass Data PTNTCCD x x x x x X X X x x x x x hh cer lf This sentence provides conditioned tilt and magnetic measurements for diagnostic use The fields are in order TiltX 32768 times tangent of angle between compass board north south axis and level plane This value is the difference between the raw tilt measurements normalized linearized and filtered according to parameter settings The pitch measurement is determined by taking the arctan of TiltX 32768 TiltY same as TiltX but for the compass board east west axis roll MagX normalized and filtered magnetic field strength along the north south axis of the compass board This value has been adjusted for any hard iron offset determined during calibration or tuned manually MagY same as MagX but along the compass board east west axis MagZ same as MagX and MagY but along the axis perpendicular to the plane of the board This value has been adjusted both for gain variation with the X Y sensor pair and for
27. larm conditions in the status fields of the HPR sentence output Tilt Settings When the tilt measured is below the warning level the status fields will indicate N 59 6 0 2 3 0 0 Tilt high warning and high alarm can be user programmed When the pitch or roll measured is between the warning and alarm levels the HPR message will indicate this with letter O in the corresponding pitch or roll status field 72 9 1 6 29 6 0 33 When the pitch or roll measured is beyond the alarm level the message will indicate this with letter in the corresponding pitch or roll status field and the heading field will be null PTNTHPR N 1 5 N P 03 Magnetometer Settings Four levels can be set for the magnetometer alarm and warning levels High Warn and Alarm levels and Low Alarm and Warning levels Five settings are generated depending on the measured total magnetic field value Mag T and the levels programmed in the EEPROM Mag Status Field Heading Field Low Warn lt Mag T lt High Warn normal High Warn lt Mag T lt High Alarm Low Alarm Mag Low Warn Mag T lt Low Alarm High Alarm lt Mag T HERMES IEEE 2 Table 4 Relationaship between the Mag total measured and the mag status field Magnetometer high alarm condition example PTNTHPR P 0 3 N 0 1 N 06 es 900240 Rev B 3 01 page 13 40 CONFIGURATION PARAMETERS This section describes the con
28. metal objects Honeywell magnetic sensors used in HMR3000 have a large field range of 1G 100 compared to 0 65 65 the maximum of earth s total magnetic field and therefore would not saturate in most platforms Calibration and compensation routines the compass can effectively compensate for static magnetic fields superimposed on the earth s field components which are used for heading calculations However compasses can not compensate for the effects of varying fields produced by dc and ac currents Level Since the HMR3000 is electronically gimbaled it is not necessary to mount the compass leveled However to get the maximum possible tilt range the compass should be mounted level when the vehicle or platform is in normal operation Orientation Forward direction of the compass can be oriented at any angle from that of the platform Use Deviation parameter to convert the compasses magnetic heading to true or magnetic heading of the vehicle platform 2 12 Calibration magnetic compasses have to be calibrated in order to compensate for magnetic fields other than the earth s field components to get accurate heading These additional magnetic fields are generated by the host and therefore depend on the compass mounting location By performing a simple procedure the HMR3000 can compensate for steady static magnetic fields known as hard iron fields Field components found after a calibration are only valid for the particular
29. nd from the 5 filtered measurements A form of non linear smoothing can be applied to the current heading to produce a smooth heading The transfer function of the algorithm is a high degree of smoothing applied for small changes in heading i e noise while little or no smoothing is applied to larger more significant changes by setting the parameters of this non linear filter In may not make sense to use the IIR filter and the non linear smoothing for a given application If the compass is mounted on a vessel that cannot change direction quickly then it is probably better to use the IIR filter and disable smoothing On the other hand smoothing works well for hand held applications or where noise is a problem 900240 Rev 3 01 page 8 3 5 Interface Pin Descriptions The table below shows pin assignments for the 9 pin D shell connector Different pins are used to supply either regulated 5 or unregulated 6V to 15V power Only one of the two power pins 9 or 8 should be connected in a given installation Name In Out Pin Description RS 232 transmit out RS 485 transmit receive signal RS 232 receive in RS 485 transmit receive return Power and signal common In 5 In Operate Calibrate input open Operate Run Stop input open Run 6 Ready Sleep input open Ready Continue Reset input open Continue Table 3 Interface Signal Descriptions A dash following a signal name is used to de
30. ne esee 3 INSTALL PC DEMO 2 0 2 20 6 eerie s ener sees ase ene 3 GETTING DATA OUT OF 3000 2 2 2 20 0 3 CONFIGURING 3000 2 60440000 4 USING PC DEMO INTERFACE csecccssececsccccescecsecccuccccsscecsecceuscecsececuccecesceuuecceuaceeneesens 4 COMMUNICATION RS485 040400000 4 INSTALLATIONS 55 meee Teese ua Dei be 5 55 5 OPERATION OF HMR3000 IN DETAIL 6 GENERAT 6 HMR3000 ELECTRICAL BLOCK 0 7 HMR3000 PROCESS CONTROL BLOCK 8 MEASUREMENT SEQUENCE e 8 INTERFACE PIN 8 0 hee e ere sae ee eer enean sen 8 COMMUNICATION teta eet sete et eeu IEEE Cd 9 lui cL A 9 OUTPUT EX K 10 QUERY FOR NMEA SENTENCES 000909 10 FORMAT OF NMEA SENTENCES 0000000000000
31. note that the signal is asserted active low In this case when pin 1 is low the Calibrate function is selected 36 Communication The HMR3000 serial communications are governed by a simple asynchronous ASCII protocol modeled after the NMEA 0183 standard Either an RS 232 or an RS 485 electrical interface can be used ASCII characters are transmitted and received using 1 start bit 8 data bits LSB first no parity MSB always 0 and 1 stop bit 10 bits total per character Baud rate can be any one of 1200 2400 4800 9600 19200 38400 The HMR3000 supports both standard NMEA 0183 and proprietary messages Unsolicited NMEA messages are sent by the HMR3000 in Continuous Mode at the rates programmed in EEPROM HMR3000 also responds to all input messages from the host An HMR3000 response to a command input may be delayed due to transmission of an unsolicited output The host must wait for HMR3000 to respond to the last command input before sending another command message communication from and to HMR3000 contain a two character Checksum Field at the end of the data fields and are denoted in the following sentences by hh The checksum assures the accuracy of the message transmitted This checksum is calculated per NMEA 0183 Standard and is outlined in section 3 11 3 7 Input There are two kinds of input to the HMR3000 request for output sentence or a setting of a configuration parameter HMR3000 sends a response to all valid inputs with a
32. ntences The three NMEA standard sentences HDG HDT and XDR and three proprietary HPR RCD and CCD messages can be queried as follows The three standard query messages accepted are TNHCQ HDG 27 lt cr gt lt lf gt TNHCQ HDT 34 lt cr gt lt lf gt TNHCQ XDR 22 lt cr gt lt lf gt The three proprietary query messages accepted are PTNT HPR 78 lt cr gt lt lf gt PTNT RCD 67 lt cr gt lt lf gt PTNT CCD 76 lt cr gt lt lf gt 3 10 Format of NMEA Sentences Output HDG Heading Deviation amp Variation HCHDG x x x x a x x a hh lt cr gt lt lf gt If either the deviation or variation parameter has not been programmed the corresponding field will be null per NMEA 0183 version 2 1 section 5 2 2 3 Parameters have not been programmed if their absolute values are greater than 3200 mils or 180 0 degrees Positive deviation and variation is indicated by a E negative values by a W Heading field will be null if it cannot be calculated see proprietary sentence NMEA requires that units for heading measurement be degrees Eg In Degree Mode HCHDG 85 8 0 0 E 0 0 E 77 HCHDG 271 2 0 0 E 0 0 E 44 HCHDG 271 1 10 7 E 12 2 W 52 HCHDG 0 0 10 7 E 12 2 W 57 Mil Mode is not allowed by NMEA standard HDT Heading True HCHDT x x T hh lt cr gt lt lf gt The heading field will be null if variation has not been programmed see HDG and Definitions or if heading cannot be calculated If deviation has not been programmed it is
33. onstant TC1 Message Type Mag Sample Rate Heading filter parameters L and S Message Rate Alarm and warning levels Hard iron coefficients Strobe mode count Figure 4 Process control diagram and user configurable parameters Measurement Sequence In normal operation the microprocessor takes a set of seven measurements four tilt and three magnetic that are combined to produce heading roll and pitch data A set of magnetic measurements can be taken at 110 55 27 5 or 13 75 Hz rate Tilt sensor is driven with a constant 55 Hz pulse Raw data are normalized linearized and filtered at the 13 75 Hz rate Normalization includes gain matching offset nulling and hard iron compensation for the three magnetic measurements and gain and offset compensation for tilt Tilt measurements are linearized to account for the non linear characteristics of the inclinometer All five measurements TiltX MagX MagY and MagZ are low pass filtered using IIR filter depending on the setting for the This filter may be disabled by setting the time constant to zero Magnetometer operation includes a Set Reset pulse to achieve high sensitivity magnetic measurements The active area of the MR element is Set or Reset periodically by a 3 amp current pulse through the patented on chip coils The periodicity of this Set Reset operation can be changed to achieve high heading accuracy or to conserve power Compass heading is calculated 13 75 times per seco
34. ors have occurred while reading writing values Do you wish to continue reading writing Jj Click on and quit the program This could be due to any one of the following HMR3000 is not connected check the cable for continuity and pin out 2 HMR3000 is not connected to the specified computer port 3 Low input voltage 5V adjust the power pack to 6 or 9 V 4 Incorrect baud rate 19200 factory setting chosen Try other baud rates 5 Ifthis error did not occur during your last session with HMR3000 it may have been configured to send a large number of messages that the computer can not handle Quit the Demo application Start a Hyper Terminal session from your Windows platform and be sure to set up this session appropriately see HMR3000 User s Guide for details for eg with 19200 baud Issue the following command to stop the compass output VFA0 320 27 CR If and try the Demo Program If the above did not resolve the problem call Honeywell B Launched PC Demo Interface but no compass output Compass is in Stop mode indicated by Red traffic light on the PC Demo Interface window Tune the compass to Run continuous mode by either clicking on the traffic light button or in Tune Parameters General tab C Compass rose does not update or is slow Compass is in Stop mode see above or HPR message rate is zero Change this message rate Tune parameters Serial Output tab Your
35. pass output Slower computers will result in large time lags between the compass output and the display All selected NMEA messages will be updated in the Display Monitor NMEA Sentences The HMR3000 output can be changed to include all or any of the six NMEA sentences each with its own rate User can capture the output messages to a file using the Capture Mode by selecting the message to be captured Diagnostics N Options menu User can also change the measurement parameters of the HMR3000 through PC Demo Interface software 28 Configuring the HMR3000 Following is a list of basic parameters that would be accessed routinely and at installation Advanced parameters that control the operation of the magnetometer heading output and warning levels are described in the Configuration Parameters section 29 Using PC Demo Interface Activate the Tune Parameters button to configure Parameter Description Located under Declination Declination General page 0 180 deg Angle between magnetic north and 0 3200 mils geographic north Add declination to magnetic heading to obtain True heading Output HDG HDT XDR HPR RCD CCD Serial Output page Noneor Messages and NMEA sentence outputs 0 1200 min Rate Rates in sentences per minute Data Filter 0 255 Time constant for IIR filter 1272 ms Heading Output L and S 0 lt 5 lt 1 Smoothing factors for non linear filter L integer gt 1 L 0 disable L lt 256 Deviation Deviation Gen
36. state of the internal Run Stop command bit controls the unsolicited output The internal Run Stop command bit is initialized to the settings saved in the EEPROM 6 0 ALGORITHM FOR THE NON LINEAR HEADING FILTER The algorithm is a s follows Assume CH current heading SH smoothed output L tuned setting integer gt 0 0 disable S tuned setting 0 lt fraction lt 1 0 disable max 0 999985 Calculate D CH SH difference G S S D L 2 saturate as D L gets large S lt lt 1 SH SH D note that SH CH for 1 These calculations are iterated at the 13 75 Hz rate u sail 900240 Rev 3 01 page 21 7 0 PHYSICAL DIMENSIONS inches centimeters e 4 200 10 67 com M 0 250 0 150 0 38 0 64 Figure 5 Housed Compass I 2 950 7 49 0 469 1 19 Jj 08 0 100 025 T 0 150 0 38 gt e 0 100 0 26 0 128 0 33 inches centimeters 1 625 4 13 l 2 0 155 029 0 320 0 81 0 0620 16 0 100 max 0 26 0 128 0 33 Figure 6 Circuit Card 900240 Rev B 3 01 page 22 Troubleshooting Guide for HMR3000 A Did not get the Card Identification message instead got the message below upon launching the PC Demo Interface program PC Demo Interface 7 Err
37. t lt If gt m hh lt CR gt lt lf gt BB1 L hh lt CR gt lt lf gt BB1 0E lt CR gt lt lIf gt L hh lt CR gt lt lf gt Table 7 Measurement Parameters 900240 Rev B 3 01 page 18 44 Serial Parameters in this section affect the serial output functions of the compass board Command Syntax Baud Rate Sets the Serial I O Baud rate Index Value 1 1200 2 2400 4 4800 8 9600 16 19200 32 BA4H 2T 24 lt CR gt lt lf gt BA4H 4T 22 lt CR gt lt lf gt BA4H 8T 2E lt CR gt lt lf gt BA4H 16T 11 lt CR gt lt lf gt BA4H 32T 17 lt CR gt lt lf gt Query Response HDG Update Rate R Query Response HDT Update Rate R Query Response XDR Update Rate Query Response HPR Update Rate Query Response RCD Update Rate Query Response CCD Update Rate Query Response ASCII Update Rate Query Response Should be followed by a Force Reset command for new rate to be active immediately or a power up is required Returns the Index value for the baud rate Sets the HDG message update rate R in sentences per minute Allowed R values are indexed with an integer I see table below Returns Index value I for HDG update rate Same as above for HDT sentence Returns the Index value I for HDT rate Same as previous for XDR sentence I Index value Returns the Index value I for XDR rate Same as previous for HPR sentence I Index value Returns the
38. wo axis tilt sensor to produce tilt compensated heading data A microprocessor controls the measurement sequence of the sensors and all the parameters that control the operation are stored in an EEPROM The output sentences of the HMR3000 conform to the NMEA 0813 standard for Marine communication 900240 Rev 3 01 page 6 The HMR3000 has four operational modes Continuous Mode Output unsolicited NMEA standard message s at a configurable rate Strobe Mode Active Strobe Mode Measurement is continuous and message output on request Passive Strobe Mode Measurement and output upon request Sleep Mode requires an interrupt signal at the connector Both measurement and output are suspended with serial inputs ignored Calibrate Mode Enter the compass in to user Hard Iron calibration mode 32 HMR3000 ELECTRICAL BLOCK DIAGRAM Regulator 5V 6 15 Vdc Tilt Sensor 2 Axis Micro Continuous Reset Magnetometers Operate Calibrate 3 Axis processor Run Stop Ready Sleep Tx Rx Gnd Analog Drive Circuits Figure 3 Electrical block diagram of HMR3000 900240 Rev B 3 01 page 7 33 HMR3000 PROCESS CONTROL BLOCK DIAGRAM User configurable parameters that control the measurement and heading calculation process is denoted at the bottom of the diagram in italic font Sensors Microprocessor Output IIR Fil ue Non Linear NMEA M Filter 6 lessages ASCII Heading Calculation Magne tometer Set Reset Interval Filter time c
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