NMEA Reference Manual

SiRF Technology, Inc. 148 East Brokaw Road San Jose, CA 95112 U.S.A. Phone: +1 (408) 467-0410 Fax: +1 (408) 467-0420 www.SiRF.com NMEA Reference Manual 1050-0042 February 2004, Revision 1.1 SiRF, SiRFstar, SiRF plus orbit design are registered in the U.S. Patent and Trademark Office. This document contains information on a product under development at SiRF. The information is intended to help you evaluate this product. SiRF reserves the right to change or discontinue work on this product without notice. NMEA Reference Manual Copyright © 1996-2004 SiRF Technology, Inc. All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or by any information storage or retrieval system without the prior written permission of SiRF Technology, Inc. unless such copying is expressly permitted by United States copyright law. Address inquiries to Legal Department, SiRF Technology, Inc., 148 East Brokaw Road, San Jose, California 95112, United States of America. phone +1 (408) 467-0410 e-mail support@sirf.com About This Document This document contains information on SiRF products. SiRF Technology, Inc. reserves the right to make changes in its products, specifications and other information at any time without notice. SiRF assumes no liability or responsibility for any claims or damages arising out of the use of this document, or from the use of integrated circuits based on this document, including, but not limited to claims or damages based on infringement of patents, copyrights or other intellectual property rights. SiRF makes no warranties, either express or implied with respect to the information and specifications contained in this document. Performance characteristics listed in this data sheet do not constitute a warranty or guarantee of product performance. All terms and conditions of sale are governed by the SiRF Terms and Conditions of Sale, a copy of which you may obtain from your authorized SiRF sales representative. Getting Help If you have any problems contact your SiRF representative or call or send an e-mail to the SiRF Technology support group: iii 100—SetSerialPort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxi 1. Output Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 GGA —Global Positioning System Fixed Data . . . . . . . . . . . . . . . . . . 1-2 GLL—Geographic Position - Latitude/Longitude . . . . . . . . . . . . . . . . 1-3 GSA—GNSS DOP and Active Satellites. . . . . . . . . . . . . . . . . . . . . . . 1-3 GSV—GNSS Satellites in View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 MSS—MSK Receiver Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 RMC—Recommended Minimum Specific GNSS Data . . . . . . . . . . . . 1-5 VTG—Course Over Ground and Ground Speed . . . . . . . . . . . . . . . . . 1-5 ZDA—SiRF Timing Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 150—OkToSend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 2. Input Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 Transport Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 NMEA Input Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 v 101—NavigationInitialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 102—SetDGPSPort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4 103—Query/Rate Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5 104—LLANavigationInitialization . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6 105—Development Data On/Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7 106—Select Datum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7 MSK—MSK Receiver Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 vi NMEA Reference Manual—February 2004 Figures xiii xiv NMEA Reference Manual—February 2004 Table 2-2 Set Serial Port Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 Tables Table 1-1 NMEA Output Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Table 1-2 Supported NMEA output messages . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Table 1-3 GGA Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 Table 1-4 Position Fix Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 Table 1-5 GLL Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 Table 1-6 GSA Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 Table 1-7 Mode 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 Table 1-9 GSV Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 Table 1-10 MSS Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 Table 1-8 Mode 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 Table 1-11 RMC Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5 Table 1-12 VTG Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5 Table 1-13 ZDA Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 Table 1-14 OkToSend Message Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 Table 2-1 Supported NMEA input messages . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 xv Table 2-3 Navigation Initialization Data Format . . . . . . . . . . . . . . . . . . . . . . . 2-3 Table 2-4 Reset Configuration - Non SiRFLoc Platforms . . . . . . . . . . . . . . . . 2-4 Table 2-5 Reset Configuration - SiRFLoc Specific . . . . . . . . . . . . . . . . . . . . . 2-4 Table 2-6 Set DGPS Port Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4 Table 2-7 Query/Rate Control Data Format (See example 1) . . . . . . . . . . . . . 2-5 Table 2-8 Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5 Table 2-9 LLA Navigation Initialization Data Format . . . . . . . . . . . . . . . . . . . 2-6 Table 2-10 Reset Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7 Table 2-11 Development Data On/Off Data Format . . . . . . . . . . . . . . . . . . . . . 2-7 Table 2-12 Select Datum Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7 Table 2-13 RMC Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 xvi NMEA Reference Manual—February 2004 Preface All SiRF product support a subset of the NMEA-0183 standard for interfacing marine electronic devices as defined by the National Marine Electronics Association. The NMEA Reference Manual provides details of NMEA messages developed and defined by SiRF. It does not provide information about the complete NMEA-0183 interface standard. Who Should Use This Guide This manual was written assuming the user has a basic understanding of interface protocols and their use. How This Guide Is Organized Chapter 1, “Output Messages” defines SiRF developed NMEA output messages. Chapter 2, “Input Messages” defines SiRF developed NMEA input messages. Related Manuals You can refer to the following for more information: • NMEA-0183 Standard For Interfacing Marine Electronic Devices. xxi Contacting SiRF Technical Support Address: SiRF Technology Inc. 148 East Brokaw Road San Jose, CA 95112 U.S.A. SiRF Technical Support: Phone: +1 (408) 467-0410 (9 am to 5 pm Pacific Standard Time) Email: support@sirf.com General enquiries: Phone: +1 (408) 467-0410 (9 am to 5 pm Pacific Standard Time) Email: gps@sirf.com xxii NMEA Reference Manual—February 2004 next sections of this chapter. Table 1-2 provides a summary of supported SiRF NMEA output messages by the specific SiRF platforms. Table 1-2 Supported NMEA output messages Message SiRF Software Options GSW2 SiRFXTrac SiRFLoc GGA Yes Yes Yes GLL Yes Yes Yes Output Messages 1 Table 1-1 lists each of the NMEA output messages specifically developed and defined by SiRF for use within SiRF products. A full description and definition of the listed NMEA messages are provided by the Table 1-1 NMEA Output Messages Option Description GGA Time, position and fix type data. GLL Latitude, longitude, UTC time of position fix and status. GSA GPS receiver operating mode, satellites used in the position solution, and DOP values. GSV The number of GPS satellites in view satellite ID numbers, elevation, azimuth, and SNR values. MSS Signal-to-noise ratio, signal strength, frequency, and bit rate from a radio-beacon receiver. RMC Time, date, position, course and speed data. VTG Course and speed information relative to the ground. ZDA PPS timing message (synchronized to PPS) 150 OK to send message 1-1 GSA Yes Yes Yes GSV Yes Yes Yes MSS Yes No No 1 GGA —Global Positioning System Fixed Data Table 1-3 contains the values for the following example: $GPGGA,161229.487,3723.2475,N,12158.3416,W,1,07,1.0,9.0,M, , , ,0000*18 Note – A valid position fix indicator is derived from the SiRF Binary M.I.D. 2 position mode 1. See the SiRF Binary Reference Manual. RMC Yes Yes Yes VTG Yes Yes Yes ZDA 2.3.2 and above No No 150 2.3.2 and above No No Table 1-3 GGA Data Format Name Example Units Description Message ID $GPGGA GGA protocol header UTC Time 161229.487 hhmmss.sss Latitude 3723.2475 ddmm.mmmm N/S Indicator N N=north or S=south Longitude 12158.3416 dddmm.mmmm E/W Indicator W E=east or W=west Position Fix Indicator 1 See Table 1-4 Satellites Used 07 Range 0 to 12 HDOP 1.0 Horizontal Dilution of Precision MSL Altitude 9.0 meters Units M meters Geoid Separation meters Units M meters Age of Diff. Corr. second Null fields when DGPS is not used Diff. Ref. Station ID 0000 Checksum *18 End of message termination Table 1-4 Position Fix Indicator Value Description 0 Fix not available or invalid 1 GPS SPS Mode, fix valid 2 Differential GPS, SPS Mode, fix valid 3-5 Not supported 6 Dead Reckoning Mode, fix valid Table 1-2 Supported NMEA output messages Message SiRF Software Options GSW2 SiRFXTrac SiRFLoc 1-2 NMEA Reference Manual—February 2004 1 GLL—Geographic Position - Latitude/Longitude Table 1-5 contains the values for the following example: $GPGLL,3723.2475,N,12158.3416,W,161229.487,A,A*41 GSA—GNSS DOP and Active Satellites Table 1-6 contains the values for the following example: $GPGSA,A,3,07,02,26,27,09,04,15, , , , , ,1.8,1.0,1.5*33 Table 1-5 GLL Data Format Name Example Units Description Message ID $GPGLL GLL protocol header Latitude 3723.2475 ddmm.mmmm N/S Indicator N N=north or S=south Longitude 12158.3416 dddmm.mmmm E/W Indicator W E=east or W=west UTC Time 161229.487 hhmmss.sss Status A A=data valid or V=data not valid Mode A A=Autonomous, D=DGPS, E=DR Checksum *41 End of message termination Table 1-6 GSA Data Format Name Example Units Description Message ID $GPGSA GSA protocol header Mode 1 A See Table 1-7 Mode 2 3 See Table 1-8 Satellite Used1 1. Satellite used in solution. 07 Sv on Channel 1 Satellite Used1 02 Sv on Channel 2 .... .... Satellite Used1 Sv on Channel 12 PDOP 1.8 Position Dilution of Precision HDOP 1.0 Horizontal Dilution of Precision VDOP 1.5 Vertical Dilution of Precision Checksum *33 End of message termination Table 1-7 Mode 1 Value Description M Manual—forced to operate in 2D or 3D mode A 2DAutomatic—allowed to automatically switch 2D/3D Output Messages 1-3 1 GSV—GNSS Satellites in View Table 1-9 contains the values for the following example: $GPGSV,2,1,07,07,79,048,42,02,51,062,43,26,36,256,42,27,27,138,42*71 $GPGSV,2,2,07,09,23,313,42,04,19,159,41,15,12,041,42*41 MSS—MSK Receiver Signal Table 1-10 contains the values for the following example: $GPMSS,55,27,318.0,100,1,*57 Table 1-8 Mode 2 Value Description 1 Fix Not Available 2 2D (<4SV’s used) 3 3D (>3SV’s used) Table 1-9 GSV Data Format Name Example Units Description Message ID $GPGSV GSV protocol header Number of Messages1 1. Depending on the number of satellites tracked multiple messages of GSV data may be required. 2 Range 1 to 3 Message Number1 1 Range 1 to 3 Satellites in View 07 Satellite ID 07 Channel 1 (Range 1 to 32) Elevation 79 degrees Channel 1 (Maximum 90) Azimuth 048 degrees Channel 1 (True, Range 0 to 359) SNR (C/No) 42 dBHz Range 0 to 99, null when not tracking .... .... Satellite ID 27 Channel 4 (Range 1 to 32) Elevation 27 degrees Channel 4 (Maximum 90) Azimuth 138 degrees Channel 4 (True, Range 0 to 359) SNR (C/No) 42 dBHz Range 0 to 99, null when not tracking Checksum *71 End of message termination Table 1-10 MSS Data Format Name Example Units Description Message ID $GPMSS MSS protocol header Signal Strength 55 dB SS of tracked frequency Signal-to-Noise Ratio 27 dB SNR of tracked frequency Beacon Frequency 318.0 kHz Currently tracked frequency Beacon Bit Rate 100 bits per second Channel Number 1 The channel of the beacon being used if a multi-channel beacon receiver is used. Checksum *57 End of message termination 1-4 NMEA Reference Manual—February 2004 1 Note – The MSS NMEA message can only be polled or scheduled using the MSK NMEA input message. See “MSK—MSK Receiver Interface” on page 2-9. RMC—Recommended Minimum Specific GNSS Data Table 1-11 contains the values for the following example: $GPRMC,161229.487,A,3723.2475,N,12158.3416,W,0.13,309.62,120598, ,*10 VTG—Course Over Ground and Ground Speed Table 1-12 contains the values for the following example: $GPVTG,309.62,T, ,M,0.13,N,0.2,K,A*23 Table 1-11 RMC Data Format Name Example Units Description Message ID $GPRMC RMC protocol header UTC Time 161229.487 hhmmss.sss Status1 1. A valid status is derived from the SiRF Binary M.I.D 2 position mode 1. See the SiRF Binary Reference Manual. A A=data valid or V=data not valid Latitude 3723.2475 ddmm.mmmm N/S Indicator N N=north or S=south Longitude 12158.3416 dddmm.mmmm E/W Indicator W E=east or W=west Speed Over Ground 0.13 knots Course Over Ground 309.62 degrees True Date 120598 ddmmyy Magnetic Variation2 2. SiRF Technology Inc. does not support magnetic declination. All “course over ground” data are geodetic WGS84 directions. degrees E=east or W=west Checksum *10 End of message termination Table 1-12 VTG Data Format Name Example Units Description Message ID $GPVTG VTG protocol header Course 309.62 degrees Measured heading Reference T True Course degrees Measured heading Reference M Magnetic1 Speed 0.13 knots Measured horizontal speed Units N Knots Speed 0.2 km/hr Measured horizontal speed Units K Kilometers per hour Mode A A=Autonomous, D=DGPS, E=DR Checksum *23 End of message termination Output Messages 1-5 1 ZDA—SiRF Timing Message Outputs the time associated with the current 1 PPS pulse. Each message will be output within a few hundred ms after the 1 PPS pulse is output and will tell the time of the pulse that just occurred. Table 1-13 contains the values for the following example: $GPZDA,181813,14,10,2003,00,00*4F 150—OkToSend This message is being sent out during the trickle power mode to communicate with outside program such as SiRFDemo to indicate whether the receiver is awake or not. Table 1-14 contains the values for the following example: 1. OkToSend $PSRF150,1*3F 2. not OkToSend $PSRF150,0*3E 1. SiRF Technology Inc. does not support magnetic declination. All “course over ground” data are geodetic WGS84 directions. Table 1-13 ZDA Data Format Name Example Units Description Message ID $GPZDA ZDA protocol header UTC Time 181813 Either using valid IONO/UTC or estimated from default leap seconds Day 14 01 TO 31 Month 10 01 TO 12 Year 2003 1980 to 2079 Local zone hour 00 knots Offset from UTC (set to 00) Local zone minutes 00 Offset from UTC (set to 00) Checksum End of message termination Table 1-14 OkToSend Message Data Format Name Example Units Description Message ID $PSRF150 PSRF150 protocol header OkToSend 1 1=OK to send, 0=not OK to send Checksum *3F End of message termination 1-6 NMEA Reference Manual—February 2004 Input Messages 2 NMEA input messages are provided to allow you to control the Evaluation Receiver while in NMEA protocol mode. The Evaluation Receiver may be put into NMEA mode by sending the SiRF Binary protocol message “Switch to NMEA Protocol - Message I.D. 129” (see the SiRF Binary Reference Manual). This can be done using a user program or using the SiRFdemo software and selecting Switch to NMEA Protocol from the Action menu (see the Evaluation Kit User’s Guide). If the receiver is in SiRF Binary mode, all NMEA input messages are ignored. Once the receiver is put into NMEA mode, the following messages may be used to command the module. Transport Message Note – All fields in all proprietary NMEA messages are required, none are optional. All NMEA messages are comma delimited. Start Sequence Payload Checksum End Sequence $PSRF1 1. Message Identifier consisting of three numeric characters. Input messages begin at MID 100. Data2 2. Message specific data. Refer to a specific message section for ... definition. *CKSUM3 3. CKSUM is a two-hex character checksum as defined in the NMEA specification. Use of checksums is required on all input messages. 4 4. Each message is terminated using Carriage Return (CR) Line Feed (LF) which is \r\n which is hex 0D 0A. Because \r\n are not printable ASCII characters, they are omitted from the example strings, but must be sent to terminate the message and cause the receiver to process that input message. 2-1 2 NMEA Input Messages Note – NMEA input messages 100 to 106 are SiRF proprietary NMEA messages. The MSK NMEA string is as defined by the NMEA 0183 standard. Table 2-1 provides a summary of supported SiRF NMEA input messages by the specific SiRF platforms. 100—SetSerialPort This command message is used to set the protocol (SiRF Binary or NMEA) and/or the communication parameters (baud, data bits, stop bits, parity). Generally, this command is used to switch the module back to SiRF Binary protocol mode where a more extensive command message set is available. When a valid message is received, the parameters are stored in battery-backed SRAM and then the Evaluation Receiver restarts using the saved parameters. Table 2-2 contains the input values for the following example: Switch to SiRF Binary protocol at 9600,8,N,1 $PSRF100,0,9600,8,1,0*0C Message MID1 1. Message Identification (MID). Description SetSerialPort 100 Set PORT A parameters and protocol NavigationInitialization 101 Parameters required for start using X/Y/Z2 2. Input coordinates must be WGS84. SetDGPSPort 102 Set PORT B parameters for DGPS input Query/Rate Control 103 Query standard NMEA message and/or set output rate LLANavigationInitialization 104 Parameters required for start using Lat/Lon/Alt3 3. Input coordinates must be WGS84. Development Data On/Off 105 Development Data messages On/Off Select Datum 106 Selection of datum to be used for coordinate transformations. MSK Receiver Interface MSK Command message to a MSK radio-beacon receiver. Table 2-1 Supported