background image

900240  Rev. B

3/01

page 10

3.8

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 Sentences

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<cr><lf>

$TNHCQ,HDT*34<cr><lf>

$TNHCQ,XDR*22<cr><lf>

The three proprietary query messages accepted are:

$PTNT,HPR*78<cr><lf>

$PTNT,RCD*67<cr><lf>

$PTNT,CCD*76<cr><lf>

3.10

Format of NMEA Sentences Output

HDG

Heading, Deviation, & Variation

$HCHDG,x.x,x.x,a,x.x,a*hh<cr><lf>

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 HPR 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<cr><lf>

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 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

Summary of Contents for hmr3000 TruePoint

Page 1: ...900240 Rev B 3 01 HMR3000 Digital Compass Module User s Guide ...

Page 2: ...32 Demo Software Disk 1 and 2 Users Manual CD Rom HMR3000 D21 485 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 OperationMode Run Output Sentences None TC1 filter 1 time constan...

Page 3: ...b and change the message rate on HPR sentence to 825 Click on the display button 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...

Page 4: ...ATION 5 2 12 CALIBRATION 5 3 0 OPERATION OF HMR3000 IN DETAIL 6 3 1 GENERAL 6 3 2 HMR3000 ELECTRICAL BLOCK DIAGRAM 7 3 3 HMR3000 PROCESS CONTROL BLOCK DIAGRAM 8 3 4 MEASUREMENT SEQUENCE 8 3 5 INTERFACE PIN DESCRIPTIONS 8 3 6 COMMUNICATION 9 3 7 INPUT 9 3 8 OUTPUT 10 3 9 QUERY FOR NMEA SENTENCES 10 3 10 FORMAT OF NMEA SENTENCES OUTPUT 10 3 11 CHECKSUM FILED 13 3 12 WARNING ANDALARM SETTINGS 13 4 0 ...

Page 5: ...terface 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 2 2 Setting up Interface and power cables Interface and power supply should be included in the Demonstration ...

Page 6: ...Figure 1 Interface and power connections for RS232 devices 2 4 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 a HMR3000 Demonstration Kit use the power and interface cable to connect between HMR3000 and your computer s COM port Make sure the line vol...

Page 7: ...rt 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 PC has slow graphic capability or if other applications are running in the background 2 7 Getting data from HMR3000 Once the power and interface cables...

Page 8: ...tton to configure Function Parameter Description Located under Range Declination Declination Angle between magnetic north and geographic north Add declination to magnetic heading to obtain True heading General page 0 180 deg 0 3200 mils Output Messages and Rate HDG HDT XDR HPR RCD CCD NMEA sentence outputs Rates in sentences per minute Serial Output page None or All 0 1200 min Data Filter TC1 Time...

Page 9: ...omponents 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 orientation and location of the compass A re calibration...

Page 10: ...st 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 Diag...

Page 11: ...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 3 2 HMR3000 ELECTRICAL BLOCK DIAGRAM Tilt Sensor 2 Axis Magnetometers 3 Axis Analog Drive Circuits Regulator EEPRROM Micro processor 5V 6 15 Vdc Continuous Reset Operate Calibrate Run Stop R...

Page 12: ... 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 second from the 5 filtered measurements A form of non linear smoothing can be appli...

Page 13: ...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 al...

Page 14: ...d XDR and three proprietary HPR RCD and CCD messages can be queried as follows The three standard query messages accepted are TNHCQ HDG 27 cr lf TNHCQ HDT 34 cr lf TNHCQ XDR 22 cr lf The three proprietary query messages accepted are PTNT HPR 78 cr lf PTNT RCD 67 cr lf PTNT CCD 76 cr lf 3 10 Format of NMEA Sentences Output HDG Heading Deviation Variation HCHDG x x x x a x x a hh cr lf If either the...

Page 15: ... 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 2B The following describe the proprietary sentences in detail HPR Heading Pitch Roll PTNTHPR x x a x x a x x a hh cr lf This sentence combines HMR3000 s three significant measurements with useful status information Data fields represent in order heading...

Page 16: ...ing 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...

Page 17: ...en 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 PTNTHPR 72 9 N 1 6 N 29 6 O 33 When the pitch or roll measured is beyond the alarm level the HPR message will indicate this with letter P in the corresponding pitch or roll status field and the heading field will be null PTNTHPR N 1 ...

Page 18: ...R3000 with the following commands Command Description Command Syntax Action Run Stop Query Response 1 Run 0 Stop Strobe mode query for Run Stop status Run Stop FA0 3 1 26 CR lf FA0 3 0 27 CR lf FA0 3 15 CR lf 1 31 CR lf 0 30 CR lf Start Compass measurements Stop Compass measurements Respond with status Force Reset Perform power up reset sequence F33 6 1 52 CR lf Initialize Filters Reset IIR filter...

Page 19: ... Decimal Hex Query Response Sets the default number base for data I O 1 decimal 0 hexadecimal query for I O number base Decimal Hexadecimal FA0 5 1 20 CR lf FA0 5 0 21 CR lf FA0 5 13 CR lf 1 31 CR lf 0 30 CR lf Deviation angle Query Response Sets the Deviation angle to value nnn n in degree mode hh is the checksum value Deviation angle IE2 nnn n hh CR lf IE2 01 CR lf nnn n hh CR lf Variation angle...

Page 20: ...scription Command Syntax Mag sample rate 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 BA6 1 39 CR lf for 13 75 Hz BA6 2 3A CR lf for 27 5 Hz BA6 4 3C CR lf for 55 Hz BA6 8 30 CR lf for 110 Hz B...

Page 21: ...meter 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 the parameter setting WB6 nnnn hh CR lf WB6 1C CR lf nnnnn hh CR lf Mag high warn Query Response 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 t...

Page 22: ...Roll status fields of the HPR output sentence when either pitch or roll output exceeds the parameter setting In degrees WE8 nn n hh CR lf WE8 15 CR lf nn n hh CR lf TC1 time constant T Query Response 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 BA2 T hh CR lf BA2 0E CR lf T hh CR lf S smoothing factor S Query R...

Page 23: ...I hh CR lf HDT Update Rate R Query Response Same as above for HDT sentence Returns the Index value I for HDT rate BAB I hh CR lf BAB 7E CR lf I hh CR lf XDR Update Rate Query Response Same as previous for XDR sentence I Index value Returns the Index value I for XDR rate BAC I hh CR lf BAC 7F CR lf I hh CR lf HPR Update Rate Query Response Same as previous for HPR sentence I Index value Returns the...

Page 24: ...f m hh CR lf XDR has MagZ Query Response Include MAGZ in XDR sentence m 1 include m 0 exclude FA1 4 0 21 CR lf FA1 4 1 20 CR lf FA1 4 13 CR lf m hh CR lf XDR has MagT Query Response Include MAGT in XDR sentence m 1 include m 0 exclude FA1 5 0 20 CR lf FA1 5 1 21 CR lf FA1 5 12 CR lf m hh CR lf Table 8 Serial I O Parameters In the current configuration software when the baud rate is changed the new...

Page 25: ... 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 i...

Page 26: ...S Figure 5 Housed Compass Figure 6 Circuit Card inches centimeters 0 062 0 16 0 812 2 06 4 200 10 67 3 250 8 26 1 500 3 81 0 188 0 46 Φ 0 150 0 38 0 250 0 64 HMR3000 Compass Module X Y Forward Roll Pitch Z S N RS 232 485 300062 0 250 0 64 0 188 0 46 ...

Page 27: ... compass output FA0 3 0 27 CR lf 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 upd...

Page 28: ...e 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 Set up 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 ...

Reviews:

Related manuals for hmr3000 TruePoint