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CW25 GPS Receiver User Manual

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1. E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 Communication Protocols continued 8 2 1 9 POLYP Position Data POLYPhhmmss sss Latitude N Longitude E AltRef FS Hacc Vacc SOG COG V_vel ageC HDOP VDOPR PDOP GDOP TDOP GU RU DR cs Name Description POLYP Navsync Proprietary NMEA sentence header Position Data hhmmss sss UTC Time in hours minutes seconds and decimal seconds format Latitude User datum latitude degrees minutes decimal minutes format ddmm mmmmmm N Hemisphere N North S South Longitude User datum longitude degrees minutes decimal minutes format dddmm mmmmmm E Longitude Direction E East W West AltRef Altitude meters above user datum ellipsoid FS Fix Status NF No Fix DR Predictive Dead Reckoning solution DA Predictive Dead Reckoning solution with DR aiding G1 Partial GPS solution with DR aiding G2 Stand alone 2D solution G3 Stand alone 3D solution D1 Partial Differential GPS solution with DR aiding D2 Differential 2D solution D3 Differential 3D solution Hacc Horizontal 2 sigma accuracy estimates 0 to 99999 meters Vacc Vertical 2 sigma accuracy estimates 0 to 99999 meters SOG Speed Over Ground knots 0 000 to 999 999 knots COG Course Over Ground true in degrees 0 00 to 359 99 degrees V_vel Vertical positive Up velo
2. 59 999 gps week GPS week number including pre GPS roll over weeks eg 1037 integer range 0 32768 gps TOW GPS Time of Week in seconds floating point range 0 0 604800 0 E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 3 4 PRTH lt Q S R gt RSET RE SET THE RECEIVER Purpose This message Sets Queries and Responds to a receiver re set command with optional actions such as clearing specific data groups stored in the CW25 DASIC battery backed memory area or entering a sleep mode The data areas that can be cleared include satellite almanacs ephemerides and receiver configuration parameters Note that sleep mode is not currently supported in the CW25 technology This command invokes a 2 second time out prior to the reset being invoked so that there are two chances on a 1Hz build of seeing the acknowledgement message first Query Format PRTHQ RSET checksum lt cr gt lt lf gt Set Format PRTHS RSET option option checksum lt cr gt lt lf gt Response Acknowledge Format PRTHR RSET option option lt checksum gt lt cr gt lt lf gt A response option of NO indicates that no reset command is currently activated Explanation of Parameters option A list of character descriptors to indicate which if any of the optional actions are to be undertaken prior to the software re sets CONFIG clear the receiver configuration data in
3. 12 available fields PDOP 3 D Position Dilution of Precision 0 00 to 99 99 HDOP 2 D Horizontal Dilution of Precision 0 00 to 99 99 VDOP Vertical Dilution of Precision 0 00 to 99 99 cs Message checksum in hexadecimal E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 Communication Protocols continued 8 2 1 4 GPGSV GPS Satellites in View The number of satellites in view together with each PRN elevation and azimuth and C No value Up to four satel lite details are transmitted in one message with up to three messages used as indicated in the first field GPGSV NoMsg MsgNo NoSv sv elv az cno sv elv az cno Cs Note designate optional sections that appear only if there is satellite data Name Description GPGSV NMEA sentence header Satellite Data NoMsg Total number of GPGSV messages being output MsgNo Number of this messages NoSv Number of satellites in view sv Satellites ID elv Satellite elevation angle degrees az Satellite azimuth angle degrees cno Satellite signal Noise ration dB Hz cs Message checksum in hexadecimal 8 2 1 5 GPRMC Recommended Minimum data The Recommended Minimum sentence is defined by NMEA for GPS Transit system data GPRMC hhmmss sss status latitude N Hemisphere longitude E spd cmg ddmmyy mv mvd Mode cs Name Description GPRMC NME
4. Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 14 Application Hints The following are a list of application hints that may help in implementing system based on the CW25 14 1 Power Supply The power supply requirements of the CW25MCM can all be provided from a single 3 3V supply To simplify system inte gration on board regulators provide the correct voltage levels for the RF and oscillator 2 9V or 3 0V and low voltage digi tal core 1 8V In power sensitive applications it is recommended that the DIG_1V8 supply is provided from a high efficiency external 1 8V source e g switch mode power supply rather than the on board linear regulator If the source impedance of the power supply to the CW25 is high due to long tracks filtering or other causes local decoupling of the supply signals may be necessary Care should be taken to ensure that the maximum supply ripple at the pins of the CW25 is 50mV peak to peak 14 2 RF Connection The RF connection to the CW25 can be done in two ways The preferred method is to use standard microstrip design tech niques to track from the antenna element to the RF_IN castellation This also allows the systems integrator the option of designing in external connectors suitable for the application The user can easily fit an externally mounted MCX SMA or similar connector provided it is placed adjacent to the RF_IN castellation If the tracking guidelines given
5. amp Time Estimated accuracy DOP x measurement accuracy While each of these terms can be individually computed they are formed from co variances and are not independent of each other For example a high TDOP will cause receiver clock errors that will eventually result in increased position errors Horizontal accuracy figure of 95 is the equivalent to 2RMS twice root mean square or twice the standard deviation radial error Similarly for vertical and time errors a figure of 95 is the value of 2 standard deviations of vertical or time error e Root mean square RMS error is the value of one standard deviation 67 of error Circular Error Probability CEP is the value of the radius of a circle centred at a position containing 50 of the position estimates e Spherical Error Probability SEP is the spherical equivalent of CEP which is centred at a position containing 50 of the position estimates CEP and SEP are not affected by large errors which could make the values an overly optimistic measurement These probability statistics are not suitable for use in a high accuracy positioning system The CW25 reports all accuracy s in the form of a standard deviation RMS value 1 5 Precise positioning service PPS This service is only available to authorised users with cryptographic equipment and special receivers Access is limited to the U S and allied military U S Government agencies and selected civil users specifically appro
6. counters 0 0 0 0 29 7 40 6 29 5 0 0 0 0 AGC counters 96 0 2 DC offset 96 AGC AGC amp Offset Mode 1 Auto 0 Off Current value of AGC 0 32 AGC counters Shows a table of 7 columns each column indicates the number of times each level has been encountered in the last integration period The columns indicate levels 3 2 1 0 1 2 3 For the example shown above only three levels are being used so all counts are either 1 O or 1 AGC Counters 96 Shows the AGC counters as a percentage For a 3 level system the optimum AGC setting should have approximately 27 in 1 and 1 and 46 in 0 this represent a Gaussian distribution DC Offset Shows the amount of imbalance in the measured signal Ideally the DC offset should be zero but will show a slight DC offset of up to a few percent due to the adjustment resolution in the RF front end E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 3 Command Format The Navsync CW25 receiver has a unique set of proprietary commands Commands will only be accepted on Port 1 The commands to and from the unit have the following general formats PRTH lt Q S R gt lt id gt lt msg fields gt lt checksum gt lt cr gt lt lf gt Where lt Q S R gt is the single ASCII character as follows Q Command a query command to the CW25 receiver S Command requires the CW25 receiver to set system settings R Response to a CW25 r
7. ood HOOUOU OUBAO 2 78 7 803 LELE 24 38 960 12 19 OOOO pae LIDUL amp ETE CEA EGOLI PIN 1 1 38 4 2 03 80 3 118 11 Figure 3 MCM Dimensions 3 3 Solder Pad Size and Placement It is recommended that the footprint of the solder pad under each castellation be 2mm x 1mm centered on the nominal center point of the radius of the castellation The castellations are gold plated and so are lead free Note that if the RF_IN connector is being used there should not be a pad or solder resist under the RF_IN castellation If the RF_IN castellation is to be used the pad should be shortened by 0 5mm underneath the CW25 and standard RF design practices must be observed The diagram below shows the placement of the pads under the castellations PIN 22 RF IN Figure 4 Solder Pad Size and Placement Pp g Noes Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 4 SIGNAL DESCRIPTION The signals on the CW25 are described in the table below All Test Control and I O ports are CMOS 3 3V compatible un less specified otherwise 4 1 Power Signals RF 3V3 Type Power Direction Input Pin 19 The RF supply input This 3 3V 10 input supplies the 3 0V LDO regulator in the RF section of the CW25 It is important that this supply is well filtered with no more that 50mV peak to peak noise with respect to RF GND RF GND T
8. Battery Backup Voltage 0 5 7 0 Volts ANT SUPPLY Antenna Supply Voltage 15 15 Volts DIG_SIG_IN Any Digital Input Signal 0 3 5 5 Volts RF_IN RF Input 15 15 Volts TSTORE Storage temperature 40 85 C IOUT Digital Signal Output Current 6 6 mA 2 4 Block Diagram RF_IN TRIM EXT_CLK Table 3 Absolute Maximum Ratings ANT_SUPPLY RF 3V8 DIG_1V8 1V8_OUT DIG_3V3 RF Block Regulator f Regulator amp Reset Front Control End E a Emulation BB25IC i i 2 IF RTC amp ps Filter EEPROM NPOR VBATT Filter Comms amp I O RF25IC Figure 1 Block Diagram E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 3 PHYSICAL CHARACTERISTICS The CW25 is a multi chip module MCM built on an FR4 fiberglass PCB All digital and power connections to the MCM are via castellations on the 25 x 27 mm PCB The RF connection is via castellations or an RF connector The general ar rangement of the CW25 is shown in the diagram below Dimensions are in mm inches 1000 27 C1063 HIROSE H FL CONNECTOR PART NO H FL R SMT 25 AF_GND 24 RF IM 23 RF GND 26 ANT SUPPLY 28 TMS 32 FREO DUT 31 USBH 30 UsBP 28 H2WDA 28 H2WCK 27 VBATT 1V8 OUT 21 JTAGSEL RTCK DIG 1V8 20 TCK m DIG_GND 19 RF_av3 pa DIG 3v3 18 RF_GNO lt EVENT_IN 17 RFV DUT ea e hu 1PP5 18 NPOR m GP10 0 PWM OUT 15 NTRST 5P10 1 TIME SYNC 14 TD GPIO 2 NEXT INT 13 ToD SPIO 3 FREQ I
9. EPH 23 409000 191EA0 D180AF B1A11B D70FED 077242 000060 124D1E 070277 308AFD DDAE47 01FB01 E8E9D6 10CBA1 0E2EB4 724279 FFCE46 BAE11B FFBA27 2454FE 1C8554 F6CD2E FFA7BD 070592 amp FE ALM 28 1283 5C4A82 OFOAF8 FD5400 A10D25 97951C 9F616D C354BE 050005868 ALM 29 1283 5D42FB 0F181D FD5E00 A10D8B 41015B C9DFD2 COS3EBO 30FFD9 amp CC WTP 1282 467144 387 3912414 78915 5020027 amp DD EPH 24 409000 191EA0 D180AF B1A11B D70FFD 797241 00001A 0639AF 7900CE 33F689 E735BA 010304 D62923 092DA1 0D77A1 724120 0041F3 849D01 005127 7C25BE 2539C7 26812C FFA692 79FC34 amp E6 ALM 30 1283 5E3DD5 0F006D FD4300 A10C7A 95D8A6 3389C4 D0357A 480018863 ALM 31 1283 5F6302 OFFBE7 FD4500 A10D3C BFB770 283629 171561 25006B amp 4D WTP 1282 467145 411 3912415 78915 5020028 amp D4 EPH 25 409201 091EA0 D180AF B1A11B D70FFO 9D7242 000007 098A6F 9DFD25 35BEA2 3A5296 FDB305 CA1705 OADBA1 OE03CB 72427D 00656E 04A569 001426 89A0F5 21F3C0 67A21D FFA678 9D02CC amp 77 ALM 01 1283 412B43 0F1879 FD5F00 A104C7 42EDF7 BC5419 3D242B 2E001E amp 67 ALM 03 1283 432F7E OFF64D FD3B00 A10D11 BEB470 15D9EF 7CA673 040031 amp 84 WTP 1282 467146 435 3912415 78915 5020028 amp DB EPH 27 409000 191EA0 D180AF B1A11B D70FF6 A17241 0000A0 2E0662 A1FBD8 349A61 E6DEFE FBE609 5CBA11 0ADAA1 0DAEAD 724135 00216F 302D23 FF4726 B8F287 221CA8 A1DOAE FFA787 A1018D amp DE 1ALM 04 1283 443663 0F0AA4 FD4
10. RED and LED GRN pins 8 amp 9 respectively Normally this signal is used to drive a green and red LED external to the module Standard software builds use these sig nal to indicate GPS status This signal has a 3 3V CMOS drive A series limiting resistor is required to limit output current to 5mA typically 470 ohms The signal return path is DIG GND LED RED LED GSN Figure 5 LED Interface The LEDs are used to indicate the operating state of the GPS receiver An initial long flash indicates the GPS fix mode RED No Fix 1pps Invalid RED and GREEN Dead Reckoning 1pps valid GREEN GPS Fix 1pps valid Each long flash may be followed by up to 12 shorter GREEN or RED flashes Each GREEN or RED short flash indicates a satellite being tracked A GREEN LED indicates a satellite being tracked and used in the time or position solution and an RED LED a satellite being tracked but not used in the solution When the GPS receiver is held in reset state the reset button pushed in all the LEDs are switched ON E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 11 ILD Network Assist Message Format This section defines the ILD Indoor Location Demonstrator format Network Assistance Base Station messages output from a Navsync Base Station These messages are suitable for use as a Network Assistance input to the CW25 receiver module They are a series of ASCII comma separated m
11. TTL Transistor transistor Logic family of digital electronic components TTFF Time to First Fix TXD Transmit Data serial communication from Data Terminal or DTE to Data Communication Equipment or DCE us uSec Microsecond u is frequently used for the Greek u symbol denoting micro one millionth part 10 UTC Coordinated Universal Time UTM Universal Transverse Mercator UART Universal Asynchronous Receiver transmitter used in serial communications VDOP Vertical Dilution of Precision WGS World Geodetic System a world wide Datum GPS works in WGS84 which has superseded WGS72 E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice Appendix 2 Contact Details For further details and hot line support please contact North American Sales NavSync Ltd 2111 Comprehensive Dr Aurora IL 60505 USA Telephone 1 630 236 3026 Facsimile 1 630 236 3023 International Sales and Support NavSync Ltd BAY 143 Shannon Industrial Estate Shannon Co Clare Ireland Telephone 353 61 472221 Facsimile 353 61 472226 Appendix 3 World Wide Web Information There are several GPS related sites on the World Wide Web www that are excellent sources to obtain further information about GPS and the current status of the satellites U S Coast Guard Navigation Center Civilian GPS service notices general system information and GPS outage r
12. URS RR PRXTER EE WERE EN S 36 11 1 7 Example Sequence Of Messages monarsi oar enne eerte enne 37 39 12 TIME ESdcE agile 40 13 FREQUENCY QUT PUD em 40 14 APPLICATION HINIES iio neue ra Died ee Lancet lida ie esi ee usui Lois ceci ai tidie Eae EEOAE 41 43 UL ENLU E JE 41 TAS E CODES OBI estesa utiiautde EE E eteteu se ieseee E EEE AE Er EES 41 14 9 Growing 5 oer cte eio co cety see oto E es eet tec E OE Lg eut uns e MEE PNE cece caer 42 14 4 Battery Backups s zo sistit enti iet ten data ooo a be Eee Ei ioa cu tht perte c 42 14 5 Over Voltage amp Reverse Polatity Protection corset tote esee ernst e poe eaii 43 14 5 Reser GENTAN mern a aN a A O EE aE e tat uela DIE 43 ace a N 43 t471 Flash Programming siii io esi I oiu crags C torte e ee dein eee en aia wie 43 APPENDIX 14 44 46 GOSS e 44 46 Xn eX PR 47 EINE 47 APPENDIX 8 47 World Wide Web INFORMATION a 53 2 cass ec oct pune inns cp sch cates deapslecsatehseagsh atid E iaai 47 APPENDIX e X 48 Tape A Heel SpecifIG BIO S seisoa zarana caeso esc cvesad ten Los deoa aed t o eate EENE ETO iE 4
13. and ephemeris data it may then be taken indoors for test with low level signals Hot starts current ephemeris data held in EEPROM can be performed with low level signals indoors 6 2 Network Assist Operation For network assist operation the Navsync Network Assistance Base Station must be connected to an external antenna and be tracking all satellites in view The network assistance data connection is provided by an RS232 link between port 3 on the network assistance base station and port 3 on the CW25 With the network assistance base station connected the development system can be started in indoor or outdoor envi ronments For more information on the Network Assistance data format please refer to section 8 4 7T Power Management The CW25 GPS receiver is a low power module consuming less than 0 6W typically for a 1Hz update of position The re ceiver contains software to dynamically reduce power consumption wherever possible Where channels and taps are not needed they are switched off When the processor is not required it is put into a halt until interrupt state and the chips clock system is geared down to reduce power consumption All of these things are performed automatically without any user configuration If further power saving is required the receiver can be reprogrammed with smaller GPS configurations thereby permanently switching off portions of the GPS hardware and allowing the processor speed to be reduced thereby saving pow
14. and most features have no difference They are two options with different software programming included The table below details the differences Options GPIO 0 PWM_OUT Dynamics PRTHS Commands CW25 NAV Defaults to 0 MHz disabled Default is 3 VERS DYNA ITIM RSET INTM 20 MHz maximum Output Maximum is 5 FRQD UxOP UxCM enabled when frequency error below 10 ppb CW25 TIM Defaults to 10 MHz Default is 1 change to 0 VERS DYNA ITTM RSET INTM 30 MHz maximum after 10 minute location FRQD UxOP UxCM Output always enabled survey completed Receiver must be and remain stationary Table 5 Differences between CW25 NAV and CW25 TIM software Notes 1 Refer to Section 8 3 10 and Section 13 2 Refer to Section 8 3 6 to see how to set PRTH lt Q S R gt DYNA Command Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 6 Operating Modes 6 1 Stand Alone Operation For stand alone operation the receiver will perform cold starts with no prior knowledge of position or GPS satellite data such as almanacs and ephemeris provided the antenna has a clear view of the sky to provide signal strengths of 35dB or higher The receiver should be allowed to track satellites for a minimum period of 15 minutes to ensure all almanac infor mation has been received The GPS data is stored in the EEPROM memory fitted to the CW25 Once the receiver has been initialised and has current almanac
15. battery backed RAM EPH clear the satellite ephemeris data in battery backed RAM ALM clear the satellite almanac data in battery backed RAM SLEEP enter a sleep mode still to be defined 8 3 5 PRTH lt Q S R gt INTM INTERMITTENT OPERATION PARAMETERS Purpose This message Queries Sets and Respond with the Fix Interval Run Duration Run Interval Horizontal and Vertical Accuracy Masks for intermittent operation Once the receiver has met the required Horizontal and Vertical Accuracy Masks it will go to sleep until the next Run Interval The receiver will also go to sleep if no fix or the accuracy masks have not been met within the Run Duration Query Format amp PRTHQ INTM checksum lt cr gt lt lf gt Set Format PRTHS INTM Fix_Interval Run_Duration Run_Interval Horizontal_Acc_Mask Vertical_Acc_Mask checksum lt cr gt lt lf gt Response Acknowledge Format PRTHR INTM lt checksum gt lt cr gt lt lf gt Explanation of Parameters Fix_Interval Interval in ms between adjacent fixes Run_Duration Maximum time in ms to attempt to obtain fix Must be greater than Fix_Interval and is 0 for continuous operation Run Interval Time interval in ms between waking to obtain a fix Must be greater than Run Duration Horizontal Acc Mask Required horizontal accuracy in meters before run completes Zero disables vertical accuracy testing Vertiacl Acc Mask Required vertical accuracy in meters before run completes Zero disa
16. be integrated with communi cations devices such as GSM CDMA UMTS modems or any other communications medium The CW25 is also optimised for the output of time frequency information Key Features of the CW25 include e Enables indoor use 185 dBW acquisition with network assist 186 dBW tracking 173 dBW acquisition stand alone e Rapid Time To Fix lt 2 second outdoor lt 5 second indoor 178dBW e Standalone CW25 module No GPS knowledge required for hardware integration Module dimensions 25 mm x 27 mm x 4 2 mm This document provides information on the Hardware and Software elements of the CW25 Key information includes Specification Physical Characteristics CW25 Dimensions castellation information Solder Pad and placement information Signal Descriptions Features Application Information The CW25 is available in a number of standard software builds depending on the application for which it is to be used In special cases the CW25 may be supplied with a slightly different hardware build The specifications in this manual refer to the standard builds E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 1 DESCRIPTION continued 1 2 GLOBAL POSITIONING SYSTEM GPS The Global Positioning System GPS is a military satellite based navigation system developed by the U S Department of Defence which is also made freely available to civil users Civilian use of G
17. below are fol lowed the impedance match will be acceptable The diagram below shows how this could be achieved In this diagram the center via of the RF connector is presumed to be plated through with a minimal pad top and bottom The PCB material is assumed to be 1 6mm thick FR4 with a dielectric constant of 4 3 Two situations are considered one with no ground plane and one with a ground plane on the bottom of the board underneath the RF connector In both cases there is no inner layer tracking under the RF connector Pin22 Y YN E FE OIX FEX Y Ground Plane if ised SMA Connector Figure 7 RF Tracking Examples The widths of the RF IN track and the associated gaps are given in the table below Scenario Track Width 1 1000 Inch Gap Width 1 1000 Inch Without ground plane 37 6 56 8 With ground plane 32 6 43 8 Table 7 RF Track amp Gap Widths Alternatively the user can attach the antenna to the Hirose H FL R SMT using a flying lead fitted with a suitable plug Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 14 3 Grounding In connecting the CW25 into a host system good grounding practices should be observed Specifically ground currents from the rest of the system hosting the CW25 should not pass through the ground connections to the CW25 This is most easily ensured by using a single point attachment for the gr
18. end for demonstrator systems This message will be superseded by new TIM and LOC messages for any end user products that use these messages WTP week TOW ECEF X ECEF Y ECEF Z FrqCal amp cs WTP 1282 467123 907 3912409 78922 5020018 amp DA Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice Name Description WTP Base Station Week Time and Position data week GPS Week Number blank if unknown TOW GPS Time of Week seconds of transmission of the character at the start of the message approx 20 msec accuracy ECEF X Base Station ECEF Position X coordinate metres ECEF Y Base Station ECEF Position X coordinate metres ECEF Z Base Station ECEF Position X coordinate metres FrqCal Optional GPS reference clock frequency calibration word The units are system dependant Under normal usage this field should be left blank cs 8 bit accumulative checksum of all bytes in between the and amp characters in hexadecimal 11 1 Message Definitions 11 1 1 EPH Ephemeris Sub frame Message This message is output approximately once a second and hence takes up to16 seconds to transmit an Ephemeris for all satellites in view EPH SV W 1 W 24 amp cs EPH 27 409000 191EA0 D180AF B1A11B D7OFF6 A17241 0000A0 2E0662 A1FBD8 349A61 E6DEFE FBE609 5CBA11 0ADAA1 ODAEAD 724135 00216F 302D23 FF4726 B8F287 221CA8 A1D
19. estimate This message has not currently been implemented In many Network Assistance applications the location provided will be the position of the Base Station itself and the un certainty will be sufficiently large to cover all possible positions that a user able to communicate with that Base Station could be located at In this case the RMS uncertainty should be set to the maximum cell size 3 for a 3 sigma limit ZLOC Lat Long Alt Unc SMaj Unc SMin Unc Brg Unc Vert amp cs For an input location of 52 14 971 N 1 09 354W and 203m altitude with a circular horizontal uncertainty of 3 km RMS and a vertical uncertainty of 200m RMS LOC 5214971 109354 203 3000 3000 0 200 amp hh Name Description LOC Location input data Lat WGS84 geodetic latitude formatted as Latitude degrees 100000 Latitude minutes 1000 ive North Lon WGS84 geodetic longitude formatted as Longitude degrees 100000 Longitude minutes 1000 ive East Alt WGS84 ellipsoidal altitude metres ive Up Unc_SMaj Horizontal RMS uncertainty semi major axis metres Unc_SMin Horizontal RMS uncertainty semi minor axis metres Unc_Brg Horizontal RMS uncertainty bearing of semi major axis degrees Unc_Vert Vertical RMS uncertainty bearing of semi major axis metres cs 8 bit accumulative checksum of all bytes in between the and amp characters in hexadecimal E Copyright 2007 NavSync Ltd All Rights Reserved Speci
20. sentence output off completely simply specify zero as the duration for that command Subsequent commands may reassign an output period to sentences disabled in this way effectively re enabling the output sentence This command also supports a shortcut by means of an ALL specifier When this is encountered the period specified is applied to all sentences An example of this is shown below where every message output on port 1 will be printed at a 5 second period with the exception of the GPRNC sentence which will be output every second and the POLYT sentence which will be disabled PRTHS U10P ALL 5 RMC 1 PLT 0 Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 9 3 UART Configuration Query SPRTHQ UxCM The command takes the form 5PRTHQ UxCM where x is a port number On the CW25 platform the port number is always between 1 and 3 inclusive The response string is of the form 5PRTHR UxCM 38400 38400 N 1 where x is the port number for which the information was requested The remainder of the string 38400 38400 N 1 represents the port Tx baud rate Rx baud rate parity and stop bits respectively A NMEA checksum of the form 4D is appended to the output string Although the format of the command supports the use of different Rx and Tx baud rates this is not currently supported by the CW25 platform Consequently the Rx and Tx baud rates returned will always be identical 9 4 U
21. 0 4425 132 50 297 1 764 10 0 023 SV 0 1000 1 0 0 X 9 O 0 000 00 0 000 SV 64 101A 6 30 19 X 9 O 0 00000 0 000 SV 64 198C 15 39 4653 45 31 242 0 481 10 0 032 SV 20 64 1B8C 15 48 0 5029 184 56 81 0 853 10 0 022 SV 13 64 1B8C 15 45 0 4317 55 44 202 2 546 10 0 034 SV 25 64 1B8C 37 0 3156 x 9 O 0 000 00 0 000 SV 3 54 101A 30 0 33 X 9 O 0 000 0 000 SV 1 64 1B8C 48 4141 208 72 SV 16 63 101B 30 0 273 x 9 THE_END EEPROM read EEPROM write e e e cOOOoOcoococcoccoccoococo CO01 I0 05 0 nmCorn Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice Software Configuration and version channels x taps x FFT points Software version and date Time tag information UTC time in hhmmss sss format Software time tag seconds since switch on Week number time of week Fix time number of seconds with 3D fix No fix time number of seconds without 3D fix Clock bias in metres Clock drift in metres Geod Latitude Longitude Ellipsoidal altitude Mean sea level altitude Local Local grid E N U from initial position Ground speed Vertical velocity Track Acc GPS Fix Fix OK flag Differential flag Estimated horizontal accuracy m Estimated vertical accuracy m Estimated position accuracy m Estimated time accuracy m Estimated speed accuracy m s Estimated frequency accuracy m s HDOP VDOP PDOP Ext T External input data e g from network assistance Altitude Position Ai
22. 4133D OFODC9 FD4100 A10C6F 16E0FE 41DD95 D2B291 EE002D amp 92 ALM 21 1283 554A57 0F067A FD4100 A10D07 EE6B06 7C6B50 24326A 0A000B amp 42 WTP 1282 467140 291 3912413 78916 5020026 amp D2 EPH 16 409000 191EA0 D180AF B1A11B D70FEB B07242 OOFFFB 01056B BOFC55 2F6C60 CEB392 FCE001 4ACF8D 1445A1 OCAE29 72427F 00039C 200047 000627 2B6F6E 1819C8 529753 FFA9D7 BOFCD3 amp A8 ALM 22 1283 5627B5 0F0C16 FD4000 A10D03 1967D9 C39FBE 9F16BE 020007 amp 5C ALM 23 1283 571E8D OFOBE4 FD5000 A10DB5 41C23B 552133 97BE38 120074 amp 42 WTP 1282 467141 315 3912413 78916 5020026 amp DO EPH 17 409000 191EA0 D180AF B1A11B D70FFD B47241 00FF92 F0B418 B4FF4C 342DAB 86653B FF3C08 CFB404 09ADA1 OD2FCE 724117 0054F6 4270E1 FF6A27 6F480E 24AD8F C5200D FFA5C4 B400CF amp 14 ALM 24 1283 584D70 0F115B FD4F00 A10D20 EE8BD9 C729AF 2413DD 060029 amp 7D ALM 25 1283 595C90 0F023B FD4700 A10D99 690B93 C0709E 3C3E96 090010 amp 3C WTP 1282 467142 339 3912413 78916 5020027 amp D8 EPH 20 409001 191EA0 D180AF B1A11B D70FF1 8D7242 000020 EE3A42 8DFC4E 302338 979E6A FC5901 34559B 118BA1 0CDAO2 72427D FFE51B D9E55F FFEF27 4328C4 1B5441 D2650C FFA85E 8DF4D2 amp DE ALM 26 1283 5A7FAC OF1A1E FD6300 A10D2F 425700 196253 685883 18008E amp 46 ALM 27 1283 5B95C2 0F0530 FD4900 A10D44 6A373F A8A532 FC1029 2E00B3 amp 55 WTP 1282 467143 363 3912414 78915 5020027 amp D6
23. 500 A10D41 ED6DD4 FDA9F2 052B62 EOFF85 amp 9E ALM 05 1283 452CD1 OFFBF7 FD3C00 A10D46 94244E 22EAF7 F70045 050016 amp 68 E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice WTP 1282 467147 459 3912415 78915 5020028 amp E2 EPH 30 409000 191EA0 D180AF B1A11B D70FEE 4E7241 OOFFF8 48D37F 4EFB8E 34F335 F1519A FC1C03 DC94E1 141EA1 0D0033 724138 FFBC9A D199EE FFD026 6D77D3 170033 909B7A FFA52A 4EFASE amp 35 ALM 06 1283 463678 0FFB30 FD4300 A10D92 COE3E9 AF2AD0 280C02 2D014F amp 72 ALM 07 1283 476B8C 0FFC42 FD4500 A10C34 BFC27E B5493D 7DE84A 36FF7D amp DA WTP 1282 467148 483 3912416 78915 5020029 amp E2 EPH 31 409000 191EA0 D180AF B1A11B D70FF3 CA7242 00006A 24E7EF CA0977 373D7D 0A92EB 07AF06 2F3ECA 125CA1 0DB9AB 72426A 0018C4 B06F84 FFAB26 251630 18BF28 2C5A53 FFA758 CA0B3B amp DB ALM 08 1283 484AA1 OFOF3E FD5700 A10C85 6DEFF7 630BEA 2ECA8F FF0004 amp D3 ALM 09 1283 49831A 0FO6BA FD4D00 A10D21 6B1798 2BACC4 1CCC36 F8FFED amp D3 WTP 1282 467149 507 391 241 7 78915 5020029 amp E1 EPH 01 409101 111EA0 D180AF B1A11B D70FF9 977242 00000F 2ECB20 9701FE 2B44A2 48C011 018D02 B391A6 110EA1 051E1D 72427D 002747 E62DBD FFE127 EDA07F 1D67BC 612361 FFAB6F 97057C amp 66 ALM 10 1283 4A3140 0F186D FD5000 A10DC1 17BA55 0CF794 AB51B6 06000F amp 4F ALM 11 1282 4B18FE 90E825 FD1400 A10CF2 ED07E2 02BFAA 7EA606 12002A amp 86 WTP 1282 467150 531 3912417 78914 5020030 amp 8CD E
24. 5020024 amp D7 EPH 11 409101 1DDDE3 D180AF B1A11B D70FE7 207080 00001B 12253A 200267 43937F DD1CA4E 022C01 8F160C 07CEA1 0D7145 70807E FFE2ED 13C163 FFE024 E8BFB7 22D002 C42A93 FF9E52 20FC47 amp 7A ALM 14 1283 4E0AB1 0F1791 FD5D00 A10CB3 41D87B BB15FC 79C4E8 FC0019 amp AB ALM 15 1283 4F4826 OFOF3F FD4C00 A10CDC EF95B3 5D7FCO 24AD4C 27003F amp C1 WTP 1282 467137 219 3912411 78916 5020025 amp D5 KLB 5 2 1 2 38 3 1 4 amp BA UCP 20 8 15 3 13 222 5 13 amp 68 ALM 16 1283 5014B5 OFOC4C FD5500 A10C39 97277F C8792E FAD2CF 010002 amp 6E ALM 17 1282 518D10 90108E FD4900 A10CD1 F63811 8FCCO7 7F941E FOFFB0 amp 8A Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice WTP 1282 467138 243 3912412 78916 5020026 amp D5 EPH 13 409000 191EA0 D180AF B1A11B D70FE8 B17242 000006 FCC7B1 B10249 2AFD13 2B281F 01F801 37728C 1117A1 OCFC41 72427F FFC547 35343B 003528 195810 1D4B25 2CC22A FFAA94 B10849811 ALM 18 1282 522AA4 900DCE FD4700 A10DOE 1DF18C 88F19F 28FEAD F7FFF8 amp FA ALM 19 1283 531D34 0F0B61 FD5700 A10C3B C40980 BO1E11 C94607 FE0028841 WTP 1282 467139 267 3912412 78916 5020026 amp DC EPH 14 409001 15DDE3 D180AF B1A11B D70FEA 987080 00FFFA FCC5C4 980134 2BC2B4 9B6179 00CD00 AA3442 10B8A1 0DOB72 70807E 002E46 D14B00 FFFD27 DF19FD 1DEDBB 5500DE FFA9E7 980618 amp 07 ALM 20 1283 5
25. 8 S lden ndo 48 NS15 UM Page 3 of 50 Rev02 Date 04 21 08 ie Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice N AV sy n C ees 1 DESCRIPTION 1 1 Introduction The CW25 GPS receiver CW25 is a small size GPS OEM module that has been specifically designed for use in weak signal GPS environments and for rapid integration into host systems while maintaining all the features of a standard GPS solution such as high accuracy Normal GPS systems cannot track satellites below 176 dBW 146 dBm however the CW25 can track down a further 10 dB resulting in tracking down to 186 dBW 156 dBm This makes it possible to track the person asset or vehicle as they enter buildings move under dense vegetation or drive through dense urban canyons Furthermore the CW25 can also acquire the satellites in these locations when using Network Assistance techniques or pre loaded information In order to obtain this level of performance the CW25 uses an innovative GPS engine built into its BB25 IC which enables the system to search in parallel 12 288 time frequency bins Not only does this enable better sensitivity but also makes for very rapid acquisition of the satellites At outdoor signal levels the time taken to obtain a hot position fix is under 2 seconds With a size of just over an inch square 25 x 27 mm the CW25 is specifically designed to
26. A sentence header Recommended Minimum Sentence hhmmss sss UTC Time in hours minutes seconds status Status V navigation receiver warning A data valid Latitude User datum latitudedegrees minutes decimal minutes format ddmm mmmmmm N Hemisphere N North or S South Longitude User datum longitude degrees minutes decimal minutes format dddmm mmmmmm E Longitude Direction E East W West spd Speed over ground knots cmg Course made good ddmmyy Date in Day Month Year format mv Magnetic variation mvd Magnetic variation direction Mode Mode Indicator D Valid Differential A Valid Autonomous E Invalid Estimated N Invalid Not Valid cs Message checksum in hexadecimal Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 Communication Protocols continued 8 2 1 6 GPVTG Course over ground and Ground speed Velocity is given as Course over Ground COG and Ground Speed GPVTG cogt T cogm M knots N kph K Mode cs Name Description GPVTG NMEA sentence header Speed and heading cogt Course over ground true T True fixed field cogm Course over ground magnetic M Magnetic fixed field knots Speed over ground knots N Knots fixed field kph Speed over ground kph K Kilometers per hour fixed field Mode Mode Indicator D Valid Differential A Valid Autonomous E Invalid Es
27. ART Configuration Set SPRTHQ UxCM The command takes the form PRTHS UxCM 57600 57600 N 1 where x is a port number On the CW25 platform the port number is always between 1 and 3 inclusive The remainder of the string 57600 57600 8 N 1 represents the port Tx baud rate Rx baud rate parity and stop bits re spectively Although the format of the command supports the use of different Rx and Tx baud rates this is not currently supported by the CW25 platform Consequently the Rx and Tx baud rates must always be specified to be the same value In addition the CW25 platform does not currently support the use of parity or of stop bit settings other than 1 stop bit The supported baud rates are 1200 2400 4800 9600 19200 38400 57600 115200 and 230400 If a command is issued which is badly formatted or does not adhere to these constraints it will be discarded This com mand is intended for use with the NMEA port s only Caution should be exercised when using this command to change the baud rate on other ports since data may be lost during the configuration change It should be noted that these commands allow the system to be configured at 1200 baud while requesting that the full set of NMEA sentences be output each second Such configurations will result in NMEA corruption since the output NMEA data rate exceeds the underlying baud rate 10 LED Interface There are two output ports designed to drive external LED s namely LED
28. CW25 GPS Receiver User Manual Issue R02 letin NS15 UM NAVSSIIC TABLE OF CONTENTS Ts DESCRIPTION ec TTE 4 6 Wed Lolo dore Tono RR 4 1 2 Global Positioning Syste Miisa atop usa EPA I EILEEN ASI RR oseaastanciagic ea ix E ENN Dd cp LEN 5 1 9 GPS Positioning and Navitatlol 2 coord ett aes t eate tote etait feoda Mandala bender oc leget cau NN 5 1 4 Standard Positioning Service SPS seid die murio Weg ao eds pese seme sa EE Cen eget et we cae 6 125 Precise Positioning Service PPS umi RE E E cg Lid ide hand c Qus pel O ut ebopt eut ndi clade aed 6 2 SPECIFICATION em 7 8 PME Zen c E if 2 2 Recommended FaUbgSsen acer ee zem dea tueatur AEO Etpeo so A Eg AAA E EAA 7 2 9 Absolute Maximum Ballligs c oai tor iet eere EHE e tote heo E e eet Sacri po eH ame PENES 8 2 4 Block DISgEatmusutie so Secs antes tastcccuent obichseaet E oiu ine ents tends tube EE coh eP eL EIS eA LIE 8 3 PHYSICAL CHARACTERISTICS uio iuter reote einer siete horti ire sec oce ciu sc lese erras ens cs cheenscecsdecsceccesaeestze 9 10 34 Physical Interface Delalls reete Lie Rte REESE reo EE Rada E ad ee eal 9 3 2 MOM DIMENSIONS cisco esa E RE ERR Ea eie aaa cb du p captas ti tU isse das tandem Col delen mers 10 3 9 Solder Pad Size and Placement xor ictu ttes ota cei ot Duet E A ea ina cid ede gaU Reads 10 ExenbiMs Heiden 11 14 LEE Power nr
29. DMA message and the size of the message data block while the message data block contains the message data and is of variable size E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 9 NMEA and UART Configuration Details This section describes how the NMEA and UART output can be configured for different Refresh Rates Contents and Baud Rates NMEA Output Configuration i e output frequency Query PRTHQ U10P PRTHQ U20P PRTHQ U3OP NMEA Output Configuration i e output frequency Set PRTHS U10P PRTHS U20P PRTHS USOP UART Configuration i e baud rate Query PRTHQ U1CM PRTHQ U2CM PRTHQ U3CM UART Configuration i e baud rate Set PRTHS U1CM PRTHS U2CM PRTHS U3CM 9 1 NMEA Configuration Query SPRTHQ UxOP The command takes the form PRTHQ UxOP where x is a port number On the CW25 platform the port number is always between 1 and 3 inclusive The remainder of the strings is of the form PRTHR UxOP GLL 1 GSV 4 PLT 1 where x is the port number for which the information was requested The specific contents supported are dependent on the NMEA sentences supported by the sys tem Only the settings which are to be altered need to be listed A NMEA checksum of the form 4D is appended to the output string The list of currently supported NMEA sentences is as shown below To turn a sentence output off completely simply specify zero as
30. Eaa aae 30 9 NMEA and VART Configuration Details 1 eceeeeeee eee eeeeeeeee ee eeee enne nnne nnn n nnns ann nitens tense tns sinas etn santa ns sn ann 31 32 9 1 NMEA Gonfiguration Query SPRTEQ UXOP etnies inier shines ans tasaeanteaddagveasenstenaende 31 9 2 NMEA Gonfiguration Set SPRTHSJUXOP screen ete retta Essi CE HR Ia IHE REPE E EAE BUR P DELE ERU dO RR u LR 31 9 3 WART Configuration Query SPRTHQ XCM itii titio ihre erdt eei F e dee aae edana 32 9 4 UART Configuration Set BPRTHQ UXGM tocco sete dust or a enna 32 JuEZSyzigielpe Fa Ai 32 11 ILD NETWORK ASSIST MESSAGE FORMAT 1 2 12a rti tenete ok cedet noc un ca cantescasexanyastesecessacesacececuctadseeutanace 33 39 DEIN ICEISQe PINI folo EN 34 39 11 1 1 EPH Ephemeris Sub frame Message sssesssessssseseeeeeeeennee nennen nnne nennt nnns 34 111 2 4ALM Almanac Subframe Message oreet reete O HRS EXEC NUES EEE EEEE 34 11 1 3 KLB Klobuchar lonospheric Parameters Message c csececeesceeeseneeseeeeeessneeneseneneeeees 35 11 1 4 UCP UTC Correction Parameters Message ssssssssssseeeneeeeeenneeeneee nnns 35 T1215 3TIM Tarte dnput Message scuta cocci att aser espe ea neo extre eret edu Peau Le 2er e Lin aE exta Po eek ut 36 11 1 6 LOG Location Message rct tesi tercie etta rE SERE ER
31. M or EPOCH output The signal return path is DIG GND GPIO 1 TIME SYNC Type I O Direction Input Output Pin 40 The GPIO 1 signal Primarily for general purpose I O this signal can also be programmed The GPIO 1 TIME_SYNC pin provides a synchronization pulse generated by the onboard RTC Custom software versions can also configure this pin for general pupose I O or an additional PPS output The signal return path is DIG_GND GPIO 2 NEXT_INT Type I O Direction Input Output Pin 41 The GPIO 2 NEXT_INT output provides an active high status indicator for the Frequency Output available on pin 39 GPIO 0 PWM Custom software versions can also configure this pin for general pupose I O The signal return path is DIG_GND GPIO 3 FREQ_IN Type I O Direction Input Output Pin 42 The GPIO 3 FREQ_IN output provides an activehigh status 3D fix indicator This indicator can also be used to determine the validity of the pin 38 1PPS output The signal return path is DIG_GND Notes 4 Accessible with custom software only 5 USB is not supported in the current software build Leave these two pins unconnected E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice E E EPA 5 Features 5 1 Power on Reset The power on reset for the CW25 is generated on board by the regulator in the RF section from the RF 3V3 signal The RF 3V3 signal must be applied t
32. N 12 TRIM 1 2 3 4 5 6 7 Pull Eo 4 2 Et 55 31 EXT CLK LED RED amp LEU GRM B NRESET 10 BOOTSEL 11 m Figure 2 CW25 Form and Size 3 1 Physical Interface Details The interface to the CW25 is via 1mm castellation on a 2mm pitch There are 42 connections in all There is also an RF connector for connecting to the GPS antenna The details of the interface connections are given below Pin Function Pin Function 1 TX 0 22 TMS 2 RX 0 23 RF GND 3 TX 2 24 RF IN 4 RX 2 EV2_IN 25 RF_GND 5 TX 1 26 ANT_SUPPLY 6 RX 1 27 VBATT 7 EXT_CLK 28 N2WCK 8 LED RED 29 N2WDA 9 LED GRN 30 USBP 10 NRESET 31 USBN 11 BOOTSEL 32 FREQ OUT 12 TRIM 33 1V8 OUT 13 TDO 34 DIG 1V8 14 TDI 35 DIG GND 15 NTRST 36 DIG 3V3 16 NPOR 37 EVENT IN 17 RFV OUT 38 1PPS 18 RF GND 39 GPIO O PWM OUT 19 RF_3V3 40 GPIO 1 TIME SYNC 20 TCK 41 GPIO 2 NEXT_INT 21 JTAGSEL RTCK 42 GPIO 8 FREQ_IN Note 3 Frequency Output is available on pin 32 FREQ_OUT with custom software only Table 4 CW25 Signal List Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 3 PHYSICAL CHARACTERISTICS continued 3 2 MCM Dimensions The figure below provides the dimensions of the positioning of the CW25 castellations Dimensions are in mm inches 1000 26 42 C1040 2 078203 13 19 520 2 ET8 13 ine
33. OAE FFA787 A1018D amp DE Name Description EPH GPS Navigation Message Ephemeris data for a single satellite See ICD GPS 200 for full details SV SV id number for the ephemeris data to follow W iJi 1 to 24 24 words of the Ephemeris subframes data from words 3 to 10 of subframes 1 2 and 3 of the GPS Navigation Message Each of the raw 30 bit data words have been logically shifted 6 bits to the right to remove the 6 parity bits leaving the 24 data bits seen in the above example cs 8 bit accumulative checksum of all bytes in between the and amp characters in hexadecimal 11 1 2 ALM Almanac Subframe Message This message is output approximately twice every seconds and hence takes up to16 seconds to transmit a complete set of Almanacs ALM SV week W 1 W 8 amp cs ALM 20 1283 54133D OFODC9 FD4100 A10C6F 16E0FE 41DD95 D2B291 EE002D amp 92 Name Description ALM GPS Navigation Message Almanac data for a single satellite See ICD GPS 200 for full details SV SV id number for the almanac data to follow week Almanac reference GPS week number W iJi 1 to 8 8 words of almanac data from words 3 to 10 of the Almanac pages of subframes 4 or 5 of the GPS Navigation Message Each of the raw 30 bit data words have been logically shifted 6 bits to the right to remove the 6 parity bits leaving the 24 data bits seen in the above example cs 8 bit accumulative checksum of all bytes in bet
34. PH 04 409000 191EA0 D180AF B1A11B D70FF3 DA7242 00FF7E E0784B DAO0CE 36AD6B 133310 00EC03 65D59D 098BA1 0D9E63 72424C FF97F2 66D059 002327 10BCB9 2490FD AD84C2 FFA4B2 DAFBFE amp 04 ALM 13 1283 4D1370 0F1B34 FD6400 A10CA5 423D1E 25448B AD34F8 FC001B amp 68 ALM 14 1283 4E0AB1 0F1791 FD5D00 A10CB3 41D87B BB15FC 79C4E8 FC0019 amp AB WTP 1282 467151 555 3912418 78914 5020030 amp D5 EPH 05 409103 1DDDE3 D180AF B1A11B D70FF7 387080 00000F 059C84 38FB53 375532 23061B FBAC02 CBD5FA 13B4A1 0DCF97 70807C FFDC99 1E10E7 000626 261485 16E322 EB337C FFA480 38F9C1 amp 93 ALM 15 1283 4F4826 0FOF3F FD4C00 A10CDC EF95B3 5D7FC0 24AD4C 27003F amp C1 ALM 16 1283 5014B5 0FOC4C FD5500 A10C39 97277F C8792E FAD2CF 010002 amp 6E WTP 1282 467152 579 3912418 78914 5020031 amp DD KLB 5 2 1 2 38 3 1 4 amp BA UCP 20 8 15 3 13 222 5 138 amp 68 ALM 17 1282 518D10 90108E FD4900 A10CD1 F63811 8FCC07 7F941E FOFFB0 amp 8A ALM 18 1282 522AA4 900DCE FD4700 A10DOE 1DF18C 88F19F 28FEAD F7FFF8 amp FA WTP 1282 467153 603 3912419 78914 5020031 amp D3 EPH 06 409001 191EA0 D180AF B1A11B D70FF5 4B7242 000145 2C7A40 4B084E 38258E 0A93F7 068403 681 3BB 1294A1 0E1379 72427F 0059C5 DCF2CA FFE026 199E24 1831AF 1F3454 FFA567 4B0CA58 amp 41 ALM 19 1283 531D34 0F0B61 FD5700 A10C3B C40980 B01E11 C94607 FE00288 amp 41 ALM 20 1283 54133D 0FODC9 FD4100 A10C6F 16E0FE 41DD95 D2B291 EE002D amp 92 Copyright 2007 NavSync Ltd All Rights Reserved Specifications s
35. PS is made available at the user s own risk subject to the prevailing DoD policy or limitations and to individuals understanding of how to use the GPS In today s satellite constellation there are a minimum of 24 operational satellites plus several operational spares in 6 orbital planes at an altitude of about 22 000 km The GPS system can give accurate 3 D position velocity time and fre quency 24 hours a day anywhere around the world GPS satellites transmit a code for timing purposes and also a Navigation message which includes their exact orbital location and system integrity data Receivers use this information together with data from their internal almanacs to pre cisely establish the satellite location The receiver determines position by measuring the time taken for these signals to arrive At least three satellites are required to determine latitude and longitude if your altitude is known e g a ship at sea and at least a fourth to obtain a 3 D fix 1 3 GPS positioning and navigation The CW25 Receiver needs to be able to see at least 4 satellite vehicles SV s to obtain an accurate 3 D position fix When travelling in a valley or built up area or under heavy tree cover you will experience difficulty acquiring and maintaining a coherent satellite lock Complete satellite lock may be lost or only enough satellites 3 tracked to be able to compute a 2 D position fix or even a poor 3D fix due to insufficient satellit
36. Parameters min_NSV Minimum Satellites used for a position time solution integer range 0 12 max_NSV Maximum Satellites used for a position time solution integer range 0 12 8 3 10 PRTH lt Q S R gt DRLM DEAD RECKONING LIMIT Purpose This message Sets Queries and Responds to the limit for the forward predictive Dead Reckoning after the last valid fix epochs The dead reckoning will progress at constant velocity for the first half of this period and then reduce to a standstill during the second half Note that since this value has units of epochs it will have a different effect on a 1Hz CW25 receiver to that on a 2Hz 5Hz or 10Hz CW25 receivers Query Format PRTHQ DRLM checksum lt cr gt lt lf gt Set Format PRTHS DRLM DR_Limit checksum lt cr gt lt lf gt Response Acknowledge Format PRTHR DRLM DR_Limit lt checksum gt lt cr gt lt lf gt Explanation of Parameters DR_Limit Number of epochs to dead reckon for integer range 0 32768 8 3 11 PRTH lt Q S R gt ELVM SATELLITE ELEVATION MASK Purpose This message Sets Queries and Responds to the satellite elevation mask angle below which satellite data will not be used in the navigation and time solution Query Format PRTHQ ELVM checksum lt cr gt lt lf gt Set Format PRTHS ELVM nvElevMask checksum lt cr gt lt lf gt Response Acknowledge Format PRTHR ELVM nvElevMask lt checksum gt lt cr gt lt lf gt Explanation of Parameters nvElevMask the navi
37. The signal return path is DIG GND TDO Type Test Direction Output Pin 13 The Test Data Out signal This is the standard JTAG test data output The signal return path is DIG GND TCK Type Test Direction Input Pin 20 The Test Clock signal This is the standard JTAG test clock input The signal return path is DIG GND TMS Type Test Direction Input Pin 22 The Test Mode Select signal This is the standard JTAG test mode input The signal return path is DIG GND JTAGSEL RTCK Type Test Direction Input Output Pin 21 This is a dual function signal When the NPOR signal is asserted low this signal is an input and selects the function of the JTAG interface When high JTAG emulation into the embedded ARMSO processor is selected When low the BB25IC chip boundary scan mode is selected The value on this signal is latched when NPOR de asserts goes high When NPOR is de asserted high and the JTAG emulation mode has been latched this signal provides the return clock to the ARM Multi ICE Because the ARMO functions off a single clock domain the TCK has to be internally synchronised in the ARMS This can cause a variable length delay in the validity of the TDO signal The RTCK is a synchronised version of the TCK signal The Multi ICE uses the RTCK output signal to indicate when the TDO signal is valid The signal return path is DIG GND Pull it to VCC DIG 3V3 through a 1K resistor for normal operation NTRST Type Test Direct
38. a erstes ubi Ea a 7 8 2 lel GPGOLE Geographic position LATO Massansagecs seek ong bent otc a aaa eA A E ia AA 17 8 21 2 GPGOA GPS Mx dalg iiie us utc quinte atiis ee ae reel a 18 8 2 1 9 GPOSA GPS DOP and Active satellites rissaa Seri pt ide I Sp D ERI R AI ER A Sm IENUE 18 8 2 1 4 GPGSV GPS Satellites in View 2 iieri entered h ce xen be tme nar nE s EE LR Roc Rd 19 8 2 1 5 GPRMC Recommended Minimum datassa eene nnne nnne nentes 19 8 2 1 6 PVTG Course over ground and Ground speed ssssseeseeeeeenneennnn 20 9 2 GPZDA UTG Tanne Aid DA sae cs tts exec e RES rares edet d dante qu cin IE 20 deba EISE EN 20 32 Mes OLY P POSON B Aber esses aie tuis cas E ex eeq c Ud rte Feud superum NE satus desis PUER cS E UE 21 8 23 10 POLYS Satellite Status e rode n teris Se cde lea a epRa tei qe um ebay ds ean ite 22 8 21 41 POLYI Additional Information Message sisian aeaaeai 22 8 2 2 Debug MeSSa GS noel tipo or petis cae a Ee Re URN HEINE pa ritus Fue ps cta ius ie adapted 23 24 98 22 1 Navigation and Timing Summary 911 2 una eripi iU etie lp ed penes 23 9222RES amp AGG data 552 5 uaimistes ace mp OT Dudes rH bel au m ee EU ted te 24 ie NS15 UM Page 2 of 50 Rev02 Date 04 21 08 N AVSY n C Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice TABLE OF CONTENTS 8 3 Command Oral cara p aaa o decree EAE AANE aA e EAEra AES 25 29 8 3 1 PRTH lt Q R gt VERS So
39. ally provided ancillary measurements e g retrieved from non volatile memory All comma separated fields following are internally provided measurements ifields TSYNC Time synchronisation CLKB Clock Bias FREQ Frequency of reference oscillator HPOS Horizontal position VPOS Vertical Position altitude VVEL Vertical Velocity DIST Distance Moved SPEED Current Speed TRACK Current track DTRACK Delta track change in direction BLANK Reserved for future use cs Message checksum in hexadecimal E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 2 2 Debug Messages The debug messages were implemented for internal testing purposes but may be useful for advanced users requiring more information than is available through the standard NMEA output messages The messages were designed to be displayed on a terminal which recognises the HOME character ASCII 11 and clear screen ASCII 12 This mode is supported in NS3Kview by switching the NMEA monitor window of NS3Kview to debug mode see section 10 3 in NS3Kview User Manual To display information on a terminal use a VT 100 emulation this will allow the information to be display static on the screen rather than being scrolling text Each information page can be commanded by sending x lt cr gt lt lf gt where x is the page number A list of the most com monly used debug pages is listed by sending 1
40. ange 18 000 0 AntHt Height of the antenna phase centre above the reference marker height defined by EIIHt above in metres floating point range 18 000 0 posRMS RMS accuracy of the input position metres floating point range O0 999999 0 Note that since the Degree Minutes and Seconds fields will accept floating point values then a decimal degree value or and integer degree decimal minute value can be input directly by setting the minutes and seconds fields to zero as appropriate eg 52 12345678 0 0 N or 52 14 123456 0 N 8 3 7 PRTH lt Q S R gt COMA COMA MODE Purpose This message Sets Queries and Responds Coma mode Coma mode puts the receiver to sleep for a predetermined period of time Query Format PRTHQ COMA checksum cr If Set Format PRTHS COMA Period checksum lt cr gt lt lf gt Response Acknowledge Format PRTHR COMA Period lt checksum gt lt cr gt lt lf gt Explanation of Parameters Period The period in milliseconds that the receiver will sleep 8 3 8 PRTH lt Q S R gt FRQD FREQUENCY OUTPUT SELECT Purpose This message Sets Queries and Responds the Frequency Output Outputs the requested frequency from the GPIO 0 port as detailed in section 13 Query Format PRTHQ FRQD checksum lt cr gt lt lf gt Set Format PRTHS FRQD Frequency checksum lt cr gt lt lf gt Response Acknowledge Format PRTHR FRQD Frequency lt checksum gt lt cr gt lt lf gt Explanation of Parameters Frequenc
41. bles vertical accuracy testing Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 3 6 PRTH lt Q S R gt ILLH INITIALIZED LAT LONG HEIGHT POSITION Purpose This message Sets Queries and Responds to the initialised geodetic position latitude longitude ellipsoidal height and antenna height above the reference marker in the receiver s current user datum The position RMS accuracy is used to decide how much importance to put on the input values and should be set with care Query Format PRTHQ ILLH checksum lt cr gt lt lf gt Set Format PRTHS ILLH LatDeg LatMin LatSec LatH LonDeg LonMin LonSec LonH EIIHt AntHt posRMS checksum lt cr gt lt lf gt Response Acknowledge Format PRTHR ILLH LatDeg LatMin LatSec LatH _LonDeg LonMin LonSec LonH EllHt AntHt posRMS lt checksum gt lt cr gt lt lf gt Explanation of Parameters LatDeg Latitude degrees floating point range 90 0 LatMin Latitude minutes floating point range 59 999999 LatSec Latitude seconds floating point range 59 99999 LatH Latitude hemisphere char N or S LonDeg Longitude degrees floating point range 90 0 LonMin Longitude minutes floating point range 59 999999 LonSec Longitude seconds floating point range 59 99999 LonH Longitude hemisphere char E or W EIIHt Height of the reference marker above the current user datum reference ellipsoid in metres floating point r
42. cial build Protocols Network Assist NMEA 0183 Proprietary ASCII and binary message formats 1pps Timing Output 30ns rms accuracy 5ns resolution Factory customisable pulse width Event Input 30ns rms accuracy lt 10ns resolution Frequency Output GPIO 0 0 MHz to 20 MHz CW25 NAV 10 Hz to 30 MHz CW25 TIM Receiver Type 12 parallel channel x 32 taps up to 32 point FFT Channels taps and FFT can be switched off to minimize power or simulate simpler designs General Processor ARM 966E S on a 0 18 micron process at up to 120 MHz Note 1 The features listed above may require specific software builds and may not all be available in the initial release 2 Please contact factory for other temperature options Table 1 CW25 Specification 2 2 Recommended Ratings Symbol Parameter Min Max Units RF 3V3 RF Supply Voltage 3 0 3 6 Volts DIG_3V3 Digital Supply Voltage 3 0 3 6 Volts DIG_1V8 Digital Supply Voltage 1 65 1 95 Volts VBATT Battery Backup Voltage 2 7 3 5 Volts ANT_SUPPLY Antenna Supply Voltage 3 0 12 Volts Table 2 Absolute Maximum Ratings Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 2 SPECIFICATION continued 2 3 Absolute Maximum Ratings Symbol Parameter Min Max Units RF_3V3 RF Supply Voltage 0 3 6 5 Volts DIG_1V8 Digital Supply Voltage 0 3 2 0 Volts DIG_3V3 Digital Supply Voltage 0 3 3 7 Volts VBATT
43. city m s 0 000 to 999 999 m s ageC Age of most recent DGPS Corrections applied seconds 00 00 to 99 99 none available HDOP 2 D Horizontal Dilution of Precision 00 00 to 99 99 VDOP Vertical Dilution of Precision 00 00 to 99 99 PDOP 3 D Position Dilution of Precision 00 00 to 99 99 TDOP Time Dilution of Precision 00 00 to 99 99 GU Number of GPS satellites used in the navigation solution RU Number of GLONASS satellites used in the navigation solution DR Dead Reckoning aiding status bits in ASCII Hex bit 0 Altitude Position Aiding applied bit 1 Vertical Velocity Aiding applied bit 2 GPS GLONASS time difference aiding applied bit 3 External Distance travelled input used bit 4 External Speed input used bit 5 External Track input used bit 6 External Delta Track input used bit 7 8 Reserved for future use cs Message checksum in hexadecimal Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 2 1 10 POLYS Satellite Status POLYS GT ID s AZM EL SN LK D s AZM EL SN LK 1D s AZM EL SN LK D s AZM EL SN LK 1D s AZM EL SN LK ID s AZM EL SN LK D s AZM EL SN LK ID s AZM EL SN LK ID s AZM EL SN LK ID s AZM EL SN LK D s AZM EL SN LK 1D s AZM EL SN LK cs Note designate optional sections that appear only if there is satellite data Name Description POLYS Navsync Proprietary NMEA sentence header Satellit
44. de longitude GPGGA Global Positioning System Fix Data GPGSA GNSS DOP and Active Satellites GPGSV GNSS Satellites in View GPRMC Minimum required sentence GPVTG Velocity and track over ground GPZDA Date and time POLYT Navsync Proprietary time of day message POLYP Navsync Proprietary status message POLYS Navsync Proprietary satellite status message GPGGA GPGSV POLYI Navsync Proprietary net assist information message Approved NMEA messages 8 2 1 1 GPGLL Geographic position Lat Lon Latitude and longitude with time of position fix and status GPGLL Latitude N Longitude E hhmmss sss Status Mode cs Name Description GPGLL NMEA sentence header Position Data Latitude User datum latitudedegrees minutes decimal minutes format ddmm mmmmmm N Hemisphere N North or S South Longitude User datum longitudedegrees minutes decimal minutes format dddmm mmmmmm E Longitude Direction E East or W West hhmmss sss UTC Time in hours minutes seconds and decimal seconds format Status StatusV navigation receiver warning A data valid Mode Mode indicator A Valid Autonomous D Valid Differential E Invalid Estimated N Invalid Not valid Cs Message checksum in hexadecimal Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 Communication Protocols continued 8 2 1 2 GPGGA GPS fix data Tim
45. de unique to each satellites message and therefore used to identify each satellite Pseudo Range The apparent measured straight line distance from a satellite to the receiving antenna at any instant in time including any errors caused by satellite clocks receiver clocks refraction of the radio waves etc PSU Power Supply Unit RAM Random Access Memory Real Numbers Numbers which may have decimal point and fractional component Resolution Smallest separation of two display elements RF Radio frequency RFI Radio Frequency Interference RMS Root Mean Square RPS Relative Positioning System RS232 Serial communication hardware standard 12v nom RS422 A serial communication hardware standard differential RTCM Radio Technical Committee for Maritime Services RTC Real time Clock maintaining approximate time when unit is off RTK Real Time Kinematic RTS Request to Send serial communication handshaking RXD Receive Data serial communication to Data Terminal or DTE from Data Communication Equipment or DCE S A Selective Availability imposed by the DoD to limit the GPS performance available to civil users SEP Spherical Error Probability SMA Miniature threaded coaxial connector SPS Standard precision Service SSR Solid State Recorder SV Satellite Vehicle TNC A standard threaded coaxial connector TSPI Time Space Position Information
46. ding APA APA required flag APA used flag Measurement Variance Residual Residual quality Sigs Instantaneous pseudorange residuals Accumulated pseudorange residuals Pseudorange edit count Instantaneous doppler residuals Accumulated doppler residuals Doppler edit count Instantaneous delta range residuals Accumulated delta range residuals Delta range edit count Reset Kalman reset flag Last reset type Number of solutions since last Kalman reset Total number of resets Number of solutions since last Kalman Q boost Week number set flag Time set flag Sufficient position flag Skip check flag Time to first fix Time to first fix ION definition Satellite Information Satellite ID Tracking status not described Measurement status Signal strength C No Mean signal strength Lock counter IODE Elevation angle Satellite used in solution flag Pseudorange residuals Pseudorange re siduals OK flag Pseudorange residuals edit flag Doppler residuals Doppler residuals OK flag Doppler residuals edit flag Delta range residuals Delta range residuals OK flag Delta range residuals edit flag EEPROM Read amp EEPROM Write Non volatile data usage The characters shown indicate what data has been read or is written to the EEPROM a almanac e ephemeris B Both almanac and ephemeris T Time P Position H Height 8 2 2 2 RF amp AGC data 52 DSP_RF_AGC 1 1 18 0 AGC amp Offset Mode Current Value 0 0 95339 130237 94423 0 0 AGC
47. e M 11 4 2 FRE IG VALS uestes A clc Mt Piste iA d Dre Petite cALE tires De eid 12 4 3 Emulation Test Signal S 2 eiie t ice eerie eae eas acre ee E EIN SEE eee ie 12 24 COMMONS Cal Sk ccce eoa te ii hactdtt etit ce tita ertet restano sei apace a aE sedetetit E captae fc ttes see e Pe da doe 13 A NONI ees 13 14 5 c i 15 Dall Power On Hesel theo RO RUBER De ER m RID meu I ash MR M IEEE 15 S2 TMe A E e 15 5 9 CW25 Embedded ldentihie atoissar aea gaye Pet space spaces ices EEE 15 54 BUI OPIONS Mec EE 15 GIOPERATING jenlgee LE 16 6 1 ie Eme cule ET 16 6 2 NODASSISIEO OMe ral Mire sence atedeaccotactn nts icts R DL ei cet E ME 16 7 POWER MANAGEMENT ge 16 rov BM COMA MOIE anas e ccna ar eE E EDD QE TM 16 8 COMMUNICATIONS PROTOCOLS nc tui terere tenente ciue sasian ua adea ceaczsecrpteesnexseuesutesestunsatzsneedsuceecsedceeeesceeanerss 17 30 Bal Bort Gontigulaliofis sesinin etn estet ipiis tors Fes iles Oe UIS tesis deo at EDEN Sive ge cel enbecc in top cA P meh ee es 17 9 2 CUTOUT Old coole Gap dpi eia E eode tp ep orae do de Partt cae geese Geena a d unc Is 17 24 8 21 NMEA MeSSag6S uio ioter shee ior rese ME a
48. e Data GT Number of GPS satellites tracked ID Satellite PRN number 1 32 S Satellite status not used U used in solution e available for use but no ephemeris AZM Satellite azimuth angle range 000 359 degrees EL Satellite elevation angle range 00 90 degrees SN Signal to noise ratio in range 0 55 dB Hz LK Satellite carrier lock count range 0 255 seconds 0 code lock only 255 lock for 255 or more seconds cs Message checksum in hexadecimal 8 2 1 11 POLYI Additional Information Message POLYI JN jammer EXT efields INT ifields BLANK cs Note More than one efield or ifield may be present each separated by commas Name Description POLYI Navsync Proprietary NMEA sentence header Additional Information JN Fixed descriptor field jammer Detected Jammer to Noise Ratio dB Hz EXT Fixed descriptor field indicates the use of externally provided ancillary measurements e g received from Network Assistance All comma separated fields following up to the INT field descriptor are externally provided measurements efields DIFF Differential Inputs TSYNC Time synchronisation CLKB Clock Bias FREQ Frequency of reference oscillator HPOS Horizontal position VPOS Vertical Position altitude VVEL Vertical Velocity DIST Distance Moved SPEED Current Speed TRACK Current track DTRACK Delta track change in direction INT Fixed descriptor field indicates the use of intern
49. e achieved by using an external supply 1V8 OUT Type Power Direction Output Pin 33 The 1 8V output from the LDO regulator that is powered by the DIG 3V3 signal Normally this is connected to the DIG 1V8 signal This loops back the regulated 1 8V to run the processor core If not connected the core will not run This may also be used to power external logic but care must be taken not to inject noise onto this signal No more than an additional 50mA may be taken from this signal by external logic DIG GND Type Power Direction Input Output Pin 35 The digital ground This is the return path for the DIG 3V3 supply and the ground reference for all the digital I O The DIG GND must be tied to the RF GND externally to the CW25 VBATT Type Power Direction Input Output Pin 27 The battery backup supply The CW25 has an on board Real Time Clock RTC This is powered from the VBATT signal A supply of typically 3V greater than 2 5V and less than DIG 3V3 should be applied to this signal This signal can be left floating if not required The input has a blocking diode and so rechargeable batteries will need an external charging circuit Typically a 1K resister in series with this signal and the external battery will provide an easy method of measuring the current consumption from VBATT during test Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change witho
50. e and position together with GPS fixing related data GPGGA hhmmss sss Latitude N Longitude E FS NoSV HDOP Altref M msl M DiffAge DiffStation cs Name Description GPGGA NMEA sentence header Position Data hhmmss sss UTC Time in hours minutes seconds and decimal seconds format Latitude User datum latitude degrees minutes decimal minutes format ddmm mmmmmm N Hemisphere N North or S South Longitude User datum longitudedegrees minutes decimal minutes format dddmm mmmmmm E Longitude Direction E East W West FS Fix Status O No fix 1 Standard GPS 2 Differential GPS NoSv Number of satellites used in the position solution HDOP 2 D Horizontal Dilution of Precision 0 00 to 99 99 AltRef Altitude metres above user datum ellipsoid M Units of height metres msl Mean Sea Level M Units of Mean Sea Level meters DiffAge Age of differential correction DiffStation Differential base station ID cs Message checksum in hexadecimal 8 2 1 3 GPGSA GPS DOP and Active satellites GPS receiver operating mode satellites used for navigation and DOP values GPGSA Smode FS sv sv sv sv DOPRHDOP VDOP cs Name Description GPGSA NMEA sentence header Satellite Data Smode A Automatic switching 2D 3D M Manually fixed 2D 3D FS Fix Status 1 No fix 2 2D GPS Fix 3 3D GPS Fix SV Satellites in use null for unused fields
51. e geometry i e poor DOP Note also that inside a building or beneath a bridge it probably will not be possible to update a position fix The Receiver can operate in 2 D mode if it goes down to seeing only 3 satellites by assuming its height remains constant But this assumption can lead to very large errors especially when a change in height does occur A 2 D position fix is not to be considered a good or accurate fix it is simply better than nothing The receiver s antenna must have a clear view of the sky to acquire satellite lock Remember always it is the location of the antenna that will be given as the position fix If the antenna is mounted on a vehicle survey pole or backpack al lowance for this must be made when using the solution To measure the range from the satellite to the receiver two criteria are required signal transmission time and signal reception time All GPS satellites have several atomic clocks that keep precise time and these are used to time tag the message i e code the transmission time onto the signal and to control the transmission sequence of the coded signal The receiver has an internal clock to precisely identify the arrival time of the signal Transit speed of the signal is a known constant the speed of light therefore time x speed of light distance Once the receiver calculates the range to a satellite it knows that it lies somewhere on an imaginary sphere whose radius is equal to this range I
52. eceiver response to a PRTH Query or an acknowledgement of a PRTH Set lt id gt is a 4 character command identifier lt msg fields gt are the message fields for the message and are all positional Optional or unknown fields are shown as nulls ie adjacent commas Trailing commas to the end of a message ie nothing but null message fields are not required lt checksum gt An optional checksum byte for checking accuracy defined as follows The checksum is displayed as a pair of ASCII characters 0 9 and A F inclusive whose value represents the HEX value of the checksum byte When used it always appears as the last field of the sentence and is prefixed by field delimiter HEX 2A instead of and followed by lt CR gt lt LF gt HEX OD 0A The checksum value is calculated by XOR ing exclusive OR ing also known as Modulo 2 Sum the 8 binary data bits of each valid data character in the sentence between the HEX 24 and HEX 2A characters The HEX 24 and the HEX 2A characters are not included in the checksum lt cr gt lt lf gt are the ASCII codes ODh and OAh carriage return and line feed respectively Some commands use multiple sentences to transfer data multiple sentence transfer shall be accomplished by means of 2 fields within the sentence for which this format is used t Total number of sentences forming the data transfer minimum value 1 x ID number of the current sen
53. eporting WWW navcen uscg gov U S Naval Observatory General USNO information and links to USNO timing and other useful sites www usno navy mil NAVSYNC GPS Homepage WWW navsync com General GPS Information and links to other userful GPS sites USAF GPS Wing www losangeles af mil National Marine Electronics Association NMEA For information on the NMEA protocol specification www nmea org General GPS Information Glossary of GPS terms www gpsworld com resources glossary htm Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice Appendix 4 Tape amp Reel Specifications I Measured from center line of sprocket hole to center line of pocket I Cumulative tolerance of 10 sprocket holes is 0 20 III Measured from center line of sprocket hole to center line of pocket IV Other material available ALL DIMENSIONS IN MILLIMETERS UNLESS OTHERWISE STATED General Tolerance 0 2 Drawing not to Scale Figure 10 Tape and Reel Solder Profile 300 4 250 Peak Temp o o 245 255 C for 15 sec Typ 200 o Reflow Zone g 150 30 90 sec 5 Min Max FE Soaking Zone 60 90 sec Typ 2 min Max 100 50 4 Ramp Slope not to exceed 3 C sec 0 r i r i r i 0 50 100 150 200 250 300 350 Time sec Figure 11 Solder Profile NAVSYNC e INASA d Noes Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to chan
54. er 7 1 Coma Mode For powered battery application which needs to reduce the power consumption it is possible to switch the receiver into Coma mode This configures the RF front end into sleep mode switches off internal peripherals and places the processor in a sleep state waiting for an interrupt Coma mode is initiated through the COMA serial command details of which can be found in section 8 3 7 Care must be taken in the implementation of the CW25 to ensure power consumption is minimized All input pins with out bias resistors have potential to float mid rail and consume power during coma mode Three GPIO pins default as inputs and do not have bias resistors GPIO 1 TIME SYNC can be factory programmed to provide either an additional PPS out put or a time synchronization input to the GPS engine GPIO 2 NEXT INT can provide an interrupt event from an active low external input GPIO S FREQ IN provide a frequency counter input Care must be taken to ensure that the pins have external bias resistors off board to ensure they are not left floating It is recommended that all unterminated test Control and I O ports are pulled high or low as appropriate making note of the active state of some ports e g BSEL with typically 100k ohms E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 Communication Protocols Full descriptions of the communications protocols used by the CW25 can be
55. ersion number Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 3 2 PRTH lt Q S R gt DYNA RECEIVER DYNAMICS Purpose This message Sets Queries and Responds to the receiver host dynamics and hence the maximum receiver tracking dynamics expected The degree of filtering performed by the navigation and timing Kalman filter is dependant on the selected receiver platform Query Format PRTHQ DYNA checksum lt cr gt lt lf gt Set Format PRTHS DYNA platform checksum lt cr gt lt lf gt Response Acknowledge Format PRTHR DYNA platform lt checksum gt lt cr gt lt lf gt Explanation of Parameters platform receiver platform integer range 0 10 Fixed base station Timing and Frequency modes etc Stationary but unknown position Man pack walking Automotive Land Vehicle Marine Airborne Low dynamics lt 1g Limit of CW25 Airborne Medium dynamics lt 2g Airborne High dynamics lt 4g Airborne Very High dynamics lt 8g Drone Missile dynamics lt 16g 10 Pure least squares mode ie semi infinite dynamics assumed Default for CW25 NAV is 3 maximum is 5 Default for CW25 TIM is 1 and changes to 0 after 10 minute location survey completed maximum is 5 OANDNAARWNM O 8 3 3 PRTH lt Q S R gt ITIM INITIALISE TIME AND DATE Purpose This message Sets Queries and Responds to the user initialised time and date Two input options are availab
56. essages which are output from UARTS of the CW25 based ILD Base Station Receiver at 38400 8 N 1 Each message starts with a character and ends with a lt CR gt lt LF gt Prior to the end of the message there is a amp character followed by an 8 bit accumulative checksum of all bytes in between the and amp characters in represented in ASCII hexadecimal For simplicity the messages that contain data normally transmitted in the GPS satellite s Navigation Messages contain the data formatted and scaled as closely as possible to it These are also very close to the data structures that are used at the NS3K and XG4K API interfaces and hence minimizes the data manipulation in the user application code outside the GPS Core API interface CW25 Antenna Port 1 d NMEA Port 2 Data CW25 Dev Kit Port 3 O H Port 4 Outdoor Antenna Port 1 Port 2 CW55 Network Assist Base Station Port 3 O Port 4 Figure 6 Network Assist Structure WTP Week Time Position Message This message is output every second provided the ILD Base Station has obtained a valid accurate 3D GPS fix in the last 60 minutes This long 60 minutes time out enables a Base Station to be initialized outdoors and then taken indoors to initialize an ILD Mobile receiver e g via a wire link without having to maintain lock on satellites itself This message does not contain any position uncertainty estimates corresponding to the known cell size as these are added at the mobile
57. f a second satellite is then found a second sphere can again be calculated from this range information The receiver will now know that it lies somewhere on the circle of points produced where these two spheres intersect When a third satellite is detected and a range determined a third sphere would intersect the area formed by the other two This intersection occurs at just two points The correct point is apparent to the user who will at least have a very rough idea of position A fourth satellite is then used to synchronise the receiver clock to the satellite clocks In practice just 4 satellite measurements are sufficient for the receiver to determine a position as one of the two points will be totally unreasonable possibly many kilometres out into space This assumes the satellite and receiver timing to be identical In reality when the CW25 Receiver compares the incom ing signal with its own internal copy of the code and clock the two will no longer be synchronised Timing error in the satel lite clocks the Receiver and other anomalies mean that the measurement of the signals transit time is in error This effectively is a constant for all satellites since each measurement is made simultaneously on parallel tracking channels Because of this the resultant ranges calculated are known as pseudo ranges To overcome these errors the CW25 Receiver then matches or skews its own code to become synchronous with the satellite signal T
58. fications subject to change without notice 11 1 7 Example Sequence Of Messages This is an example of a sequence of message for a Demonstrator system i e WTP messages are used rather than the new and still to be implemented TIM and LOC messages The blank line does not exist in reality and has only been inserted to show where a gap exists in the transmission bursts WTP 1282 467130 051 3912410 78920 5020020 amp BD EPH 01 409101 111EA0 D180AF B1A11B D70FF9 977242 00000F 2ECB20 9701FE 2B44A2 480011 018D02 B391A6 110EA1 051E1D 72427D 002747 E62DBD FFE127 EDAO7F 1D67BC 612361 FFAB6F 97057C amp 66 ALM 31 1283 5F6302 OFFBE7 FD4500 A10D3C BFB770 283629 171561 25006B amp 4D ALM 01 1283 412B43 0F1879 FD5F00 A104C7 42EDF7 BC5419 3D242B 2E001E amp 67 WTP 1282 467131 075 3912410 78919 5020021 amp CD EPH 04 409000 191EA0 D180AF B1A11B D70FF3 DA7242 00FF7E E0784B DAOOCE 36AD6B 133310 00EC03 65D59D 098BA1 0D9E63 72424C FF97F2 66D059 002327 10BCB9 2490FD AD84C2 FFA4B2 DAFBFE amp 04 ALM 03 1283 432F7E OFF64D FD3B00 A10D11 BEB470 15D9EF 7CA673 040031 amp 84 ALM 04 1283 443663 0F0AAA4 FD4500 A10D41 ED6DD4 FDA9F2 052B62 E0FF85 amp 9E WTP 1282 467132 099 3912410 78919 5020022 amp D5 EPH 05 409103 1DDDE3 D180AF B1A11B D70FF7 387080 00000F 059C84 38FB53 375532 23061B FBACO2 CBD5FA 13B4A1 ODCF97 70807C FFDC99 1E10E7 000626 261485 16E322 EB337C FFA480 38F9C1 am
59. floating then the CW25 boots from its on chip FLASH memory If the BOOTSEL signal is pulled low the CW25 boots from its on chip ROM 4 5 I O Signals TX 0 Type I O Direction Output Pin 1 The transmit signal for UART 1 This is a standard UART output signal The signal return path is DIG_GND TX 1 Type I O Direction Output Pin 5 The transmit signal for UART 2 This is a standard UART output signal The signal return path is DIG_GND TX 2 Type I O Direction Output Pin 3 The transmit signal for UART 3 This is a standard UART output signal The signal return path is DIG_GND RX 0 Type I O Direction Input Pin 2 The receive signal for UART 1 This is a standard UART input signal The signal return path is DIG_GND RX 1 Type I O Direction Input Pin 6 The receive signal for UART 2 This is a standard UART input signal The signal return path is DIG_GND RX 2 EV2_IN Type I O Direction Input Pin 4 This is a dual mode signal Normally this is the receive signal for UART 3 a standard UART receive signal Under software control it can also be used as general purpose I O or to detect events It can be used to detect the timing of the leading edge of the start bit of the incoming data stream The signal return path is DIG_GND FREQ_OUT Type I O Direction Input Output Pin 32 Optional frequency output signal It is NOT the same signal as Pin 39 This signal is turned off by default Th
60. found in section 8 2 and 8 3 8 1 Port Configuration There are three serial ports available on the CW25 They are three UARTs of the CW25 receiver These are configured as follows Port Baud Rate Function 38400 NMEA 38400 Debug 38400 Network Assistance Table 6 Port Configurations All ports are configured as 8 bits no Parity with no handshaking 8 2 Output Format There are two types of messages that can be output from the CW25 receiver these are split into NMEA sentences and Debug messages Both types of outputs are ASCII strings 8 2 1 NMEA Messages There are two main types of sentence Approved and Proprietary All sentences start with delimited with commas and ending with lt CR gt lt LF gt Approved sentences are recognized by the first 5 characters after the which define both the kind of talker providing the information 2 characters GP in the case of a GPS and the type of information 3 characters Proprietary sentences are indicated by a P following the as the first of the 5 characters the next 3 indicating the manu facturer from a listing of mnemonic codes and the 5th character being selected by that manufacturer for the particular sentence structure Proprietary sentences must conform to the general NMEA structures but are otherwise undefined out side of the Manufacturers own documentation The following Approved messages are available from the CW25 receiver GPGLL Geographic Position Latitu
61. ftware Version cccccccsssssccceccesceceeeeeececesessesesesessesaauuaesaeaeaeeeeeeeeeeeeeseserens 25 9 9 2 PATH lt O S Rs DYNA RECEIVER DYNAMIGS i csecsiccecsscesioct snes Sea daavasdesaagods apated ncteeaanneteeaeneags 26 8 3 3 PRTH amp QIS E S ITIM INITIALISE TIME AND DATE ssccctscc tvendseeasites pe ect rot thee urere neto cr han 26 9 9 4 PRTHSOISIES RSET RE SET THEREGEIVERU iieri RR Ep eth eee Fert net nepote PP ease 27 8 3 5 PRTH lt Q S R gt INTM INTERMITTENT OPERATION PARAMETERS esee 27 8 3 6 PRTH lt Q S R gt ILLH INITIALIZED LAT LONG HEIGHT POSITION seeeeeenne 28 8 3 7 PRTH amp QISIBs GOMA COMA MODE essai etin eo cio cese tle ete e rae Sadan De ta dee rece eg 28 9 9 9 PRTAH lt OISIR gt FROD FREQUENCY OUTPUT SELECT 2 352 stat meets E SEE eorr heats 28 8 3 9 PRTH lt Q S R gt MMSV MIN amp MAX SATELLITES FOR A POSITION SOLUTION 29 8 3 10 PRTH GISIRS DREM DEAD RECKONING LIMIT sia inpr ioi tete te Ee Een hp Rte aeaio 29 8 3 11 PRTEH OISIR ELVMESATELLITE ELEVATION MASK 2 2 ia cta nct treten enne thee ec iccds 29 8 4 INelwork Assistance InpUl zs eo eoo terio o RE steh de tud x oer aid aed eut cU Red EE pee ds 30 8 4 1 Message Definitioti 1 rte re Ide HR ets det Jk EE E REIR rn te rho sms ca ckdue crie a sb e besde para 30 9 42 The GDMA MOSSaQG diac ERR ERR Ga ap RIA zeae NER L decus etia ined actos tee SESS pe tui et sat ux T
62. gation and time solution elevation mask angle in degrees integer range 0 90 Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 4 Network Assistance Input The CW25 uses network assistance data to allow acquisition and tracking of GPS satellites in low signal levels The net work assistance data is base on the TIA EIA IS 801 specification as using the CDMA network The format used is an ASCII version of the data to allow the contents of the messages to be displayed on a terminal The data format is that used by the Navsync Network Assistance Base Station Simulator This section defines the transport mechanism for transferring the CDMA GPS messages in serial form from the Base Sta tion Simulator in TIA EIA IS 801 format As only a subset of the whole message set defined in TIA EIA IS 801 is required this section defines the format for each of the required messages and provides references to the relevant section of TIA EIA IS 801 Three messages are required Base Station response Provide Location Response message TIA EIA IS 801 section 4 2 4 2 page 4 51 Base Station response Provide GPS Almanac message TIA EIA IS 801 section 4 2 4 2 page 4 41 Base Station response Provide GPS Ephemeris message TIA EIA IS 801 section 4 2 4 2 page 4 44 The messages should be sent out in the order Provide Location Response Provide GPS Almanac and Provide GPS Ephemeris The messages are variable le
63. ge without notice Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice N AVSY C CW25 User Manual Revision Revision Date Notes P 0 1 01 24 07 Preliminary User Manual P 0 2 05 03 07 Updated to new Format V1 0 08 26 07 Updated to Released Version V1 03 11 07 07 Revisions and Edits Update R02 04 21 08 Data Updates amp Update to new Revision System NavSync Ltd Europe Bay 143 Shannon Industrial Estate Shannon Co Clare Ireland Phone 353 61 475 666 E mail sales navsync com North America 2111 Comprehensive Drive Aurora IL 60505 USA Phone 630 236 3026 E mail northamerica navsync com www navsync com
64. he band of radio frequencies between 1 and 2 GHz Lithium A metallic element used in batteries LMT Local Mean Time mA Milliamp of current Macro Text containing frequently used operations which can be executed as a single command DM only MHz Megahertz i e one million cycles per second mph Miles per Hour MSL Mean Sea Level geoidal height 0 MIL STD Military Standard Multiplexing A receiver channel can track multiple satellites by switching rapidly between them so as to gather all data transmissions NMEA National Marine Electronics Association NMEA 0183 A serial communication standard defining hardware compatibility message formats and a range of standard messages OTF On The Fly carrier phase ambiguity resolution The ability to resolve integer carrier phase ambiguities in real time while moving n mile International Nautical Mile 1852 metres 6076 1 feet 1 15 statute miles ns nSec Nanosecond one thousandth of a microsecond i e 10 second PC Personal Computer IBM compatible PCB Printed circuit Board P code The Precise or Protected GPS code not available to civil users PDOP Position Dilution of Precision including horizontal and vertical components pps PPS Pulse per Second and Precise Positioning Service Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice Glossary continued PRN Pseudo Random Noise co
65. his is repeated for all satellites in turn thus measuring the relative transit times of individual signals By accurately knowing all satellite positions and measuring the signal transit times the user s position can be accurately determined Utilizing its considerable processing power the CW25 Receiver rapidly updates these calculations from satellite data to provide a real time position fix Memory options allow storage of navigation and position data for subsequent post pro cessing or post mission analysis all within a single unit Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 1 DESCRIPTION continued 1 4 Standard positioning service SPS Civil users worldwide are able to use the SPS without restriction or charge Dilution Of Precision DOP is a measure of the satellite geometry and is an indicator of the potential quality of the solu tions The lower the numerical value the better the potential accuracy for example a PDOP below 3 indicates good satel lite geometry For 3 D positioning fluctuations in DOP can be harmful to the solution especially in Kinematic Dynamic modes The following DOP terms are computed by CW25 HDOP Horizontal Dilution of Precision Latitude Longitude VDOP Vertical Dilution of Precision Height TDOP Time Dilution of Precision Timing errors PDOP Position Dilution of Precision 3 D positioning GDOP Geometric Dilution of Precision 3 D position
66. ion Input Pin 15 The Test Reset signal This is the active low JTAG test reset signal The signal return path is DIG GND Pull it to ground through a 1K resistor for normal operation E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 4 SIGNAL DESCRIPTION continued 4 4 Control Signals NPOR Type Control Direction Input Output Pin 16 The Power On Reset signal This active low open collector signal is the master reset for the CW25 This should be driven with an open collector reset circuit for a minimum of 100ms An external pull up is not required if the 100K internal pull up is sufficient The CW25 can be held in reset by asserting this signal The signal can be used to reset external circuitry but care must be taken to ensure no DC current is drawn from this signal as the internal pull up resistor value is 100K NRESET Type Control Direction Input Output Pin 10 The system reset signal This active low open collector signal is generated by the BB25IC chip in response to the assertion of the NPOR It may also be driven to reset the ARM9 processor in the BB25IC without completely re initialising the chip BOOTSEL Type Control Direction Input Pin 11 TThe boot select signal The BB251C has four boot up modes but only two are supported by the CW25 This signal is sampled when the NPOR is de asserted If the BOOTSEL signal is high or left
67. is is a complex signal which under software can provide any of either an NCO generated output frequency a PWM signal a GPS aligned EPOCH pulse or general purpose I O signal The signal return path is DIG_GND 1PPS Type I O Direction Input Output Pin 38 The 1 pulse per second signal This is normally a 1 pulse aligned with GPS time but can under software control also provide general purpose I O or an additional even input The pulse width of the 1PPS is software selectable with a default of 100us The signal return path is DIG_GND Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 4 SIGNAL DESCRIPTION continued 4 5 I O Signals continued EVENT_IN Type I O Direction Input Output Pin 37 The event input signal This is normally an event timer or counter Events are timed against GPS time Under software control this input can be used as an external 48 MHz input for the USB interface or this input can also be used for general purpose I O The signal return path is DIG GND N2WCK Type I O Direction Input Output Pin 28 The NavSync 2 Wire Clock signal This is the open collector IC compatible clock signal for the 2 wire serial interface The signal return path is DIG_GND N2WDA Type I O Direction Input Output Pin 29 The NavSync 2 Wire Data signal This is the open collector IPC compatible data signal for the 2 wire serial in
68. ive checksum of all bytes in between the and amp characters in hexadecimal Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 11 1 5 TIM Time Input Message This message is output every seconds to provide an approximate starting GPS Time This message has not currently been implemented TIM week TOW TOW rms FS TOW FS rms amp cs Without a Frame Synch pulse input TIM 1282 467123 907 10 amp hh With a 1PPS with 100 nsec RMS accuracy used as a Frame Synch pulse input TIM 1282 467123 907 10 467123 000000000 100 amp hh Name Description TIM Time input data week GPS Week Number blank if unknown TOW GPS Time of Week seconds of transmission of the character at the start of the message TOW_rms RMS accuracy integer milliseconds of the above TOW relative to when the character was transmitted FS_TOW GPS Time of Week seconds of the last Frame Synch pulse inserted Leave blank if it is unknown or no pulse was sent FS_rms RMS accuracy FrqCal Optional GPS reference clock frequency calibration word The units are system dependant Under normal usage this field should be left blank cs 8 bit accumulative checksum of all bytes in between the and amp characters in hexadecimal 11 1 6 LOC Location Message This message is output every seconds and provides an estimate of the user s location along with an uncertainty for this
69. le one allowing a calendar date and GMT time to be input and the other a GPS week number and seconds of week The input date is acted upon regardless and is primarily used to set the GPS week inside the receiver The time input will not be used if is set to zero or if the receiver is currently tracking any satellites and therefore already has a good sub millisecond knowledge of time If the time input is not used then the Response message returns the values used or assumed instead of those input The time RMS accuracy is used to decide how much importance to put on the input values and should be set with care Query Format PRTHQ ITIM checksum lt cr gt lt lf gt Set Format Using a GMT time format PRTHS ITIM timeRMS GMT day month year hours minutes seconds checksum lt cr gt lt lf gt Using a GPS time format PRTHS ITIM timeRMS GPS gps_week gps_time checksum lt cr gt lt lf gt Response Acknowledge Format PRTHR ITIM timeRMS GMT day month year hours minutes seconds GPS gps_week gps_time lt checksum gt lt cr gt lt lf gt Explanation of Parameters time RMS RMS accuracy of the input time tag seconds floating point range 0 999999 0 day day of month integer range 1 31 month month of year integer range 1 12 year 4 digit year integer range 1980 2047 hours hours of day integer range 0 23 minutes minutes of hour integer range 0 59 seconds seconds of minute floating point range 0
70. lt cr gt lt lf gt as shown below Screens 11 52 NV_RAM 4980 NA_RAM 3288 Stacks 3968 dsp_SD 12240 The above example shows that debug screens 11 and 52 are available The additional information details the amount of memory used within the systems for Non volatile memory Network Assistance data Stacks and DSP data memory To display any of the available debug screens simply type x lt cr gt where x is the screen number e g 11 lt cr gt Each of the above information pages is detailed below The debug information is not limited to the above list and spe cial debug pages may be available depending on the software within the receiver Any additional pages specific to soft ware versions are not described in this manual 8 2 3 1 Navigation and Timing Summary 11 Navigation Summary Page 12x32x32x16 CW25 1 741 May 10 2004 15 03 41 Time 140533 70 3840 1270 137133 7081 15 0 569556 04 675 87 Geod 52 1458 28304N 1 921 20855 E 209 19 161 75 Local 921 146 15325 118 83 187 0 009 0 007 193 89 0 015 Acc 5510 34 101 106 95 95 0 24 0 15 1 70 2 43 2 97 ExtT 0 0 000 0 000 0 0 000000 0 000 0 0 000 0 000 APA 0 0 000 0 000 0 000 VVA O 0 000 0 000 0 000dy2TO 0 Sigs 1 569 1 235 0 000 0 100 0 003 0 006EC 0 0 OJNO VarF 0 011 0 007 0 000 0 072 0 002 0 007811 1 024 cr0 ts 0 Reset 093 48 130 QB 022 13 ST 1 SUB_MS SP10 FF 48 5 SV 11 64 1B8C 15 35 0 4403 228 13 144 4 041 10 0 033 SV 32 64 104A 6 31 444 x 9 O 0 000 00 0 000 SV 64 1B8C 15 46
71. manac Data transmitted by each satellite and which provides the approximate orbital information of all the GPS satellites constellation i e a timetable Antenna Also called Aerial the device for receiving the radio signals ASCII A standard digital format for alpha numeric characters American Standard Code for Information Interchange Baud Serial digital communication speed units bits per second BIT Built in Test CDU Control Display Unit CEP Circular Error Probability Channel The satellite tracking unit of a GPS receiver One channel may track more than one satellite by multiplexing but for best performance each satellite should be continuously tracked by a dedicated channel so more than one channel is often integrated into a receiver CMOS A type of semiconductor fabrication process Complementary Metal Oxide Semiconductor resulting in low power CMOS devices require static protection during handling C No Carrier to Noise ratio a measure of signal quality COM Port Communication port e g PC serial communication ports COM1 etc CONUS Continental United States CPU Central Processing Unit usually the microprocessor CTS Clear to Send serial communication handshaking Datum The reference shape of the Earth s surface used in the construction of a map or chart Usually chosen for a best fit over the area of interest and thus the Datum for various parts of the wo
72. ngth and flags within the messages identify the inclusion or exclusion of various sub fields If all of the data for a message is not valid then the message should be omitted If any of the data for a message is valid then the message should be sent The message syntax is specified in BNF Backus Naur Form 8 4 1 Message Definition MessageSet lt MessageLine gt MessageLine lt Header gt lt MsgHexOctets gt lt Footer gt Header lt GSMHeader gt lt CDMAHeader gt CDMAHeader CDMA lt CDMAType gt lt CDMAMessage Type gt CDMAType 0 Note 0 specifies TIA EIA IS 801 format Other values reserved for future use CDMAMessageType 0 1 2 Note 0 Provide Location Response 1 Provide GPS Almanac 2 Provide GPS Ephemeris MsgHexOctets lt HexOctet gt message data HexOctet The data content of the MsgHexOctets data is defined in section 2 of this document Footer amp lt Checksum gt lt CR gt lt LF gt Checksum HexOctet Note Lower 8 bits of the addition of all characters between the starting and the amp before the checksum non inclusive CR ASCII carriage return character LF ASCII line feed character 8 4 2 The CDMA Message The CDMA message data is contained in the MsgHexOctets field of the top level message format defined above Each CDMA message consists of a message header block followed by a message data block The message header block is fixed size and identifies the type of C
73. o the CW25 at the same time as the DIG 3V3 if the on board power on reset is to be used If an external source of reset is to be applied to the NPOR signal after both the RF 3V3 and the DIG 3V3 signals are valid this restriction does not apply 5 2 Time Transfer In order to aid time transfer between fixes during which the CW25 has been unable to maintain an accurate perception of time eg In deep sleep or powered down states the on board RTC can be set to provide a signal derived from the 32 768Hz crystal 5 3 CW25 Embedded Identification The hardware version number is hard coded onto the CW25 firmware also contains a version number allowing for easy identification of the hardware and software version in embedded applications 5 4 Build Options There are two versions of the CW25 available CW25 NAV This is the general navigation version of the CW25 GPS Receiver It includes Network Assistance which al lows the receiver to be sent ephemeris data from a base station such as the CW55 over a communications link which allow the receiver to acquire initial positional lock in harsh environments down to signal levels of 185dBW 155dBm CW25 TIM This version of the CW25 has position hold software included which allows for very stable output frequency control for timing applications CW25 TIM has network assistance and stand alone operation also See specification in Section 2 1 These two options have same physical characteristics
74. ound There must also be a good connection between the RF_GND and the DIG_GND signals Whilst there is not a specific need to put a ground plane under the CW25 high en ergy signals should not be tracked under the CW25 It is however recommended that a ground plane be used under the CW25 In this case the following would be an example of the pattern that may be used E mmm Double via to host System ground at EF this one point fia Digital and RF m grounds common m at this location only CI Ez Figure 8 Grounding the CW25 with a ground plane 14 4 Battery Backup The CW25 has an on board real time clock RTC This is used to store date and time information whilst the CW25 is pow ered down Having a valid date and time speeds the time to first fix TTFF allowing the CW25 to meet its quoted TTFF specification The CW25 relies on an external power source to power the RTC VBATT when the DIG 3V3 is not present If the user application does not require the warm or hot fix performance or the required information is provided by network assistance there is no need to provide the VBATT signal The VBATT signal must be greater than 2 6V and less than DIG 3V3 0 6V Typically a 3V lithium primary cell or a high capacity supercap will be used The CW25 has an internal blocking diode so if a supercap or rechargeable batte
75. p 93 ALM 05 1283 452CD1 OFFBF7 FD3C00 A10D46 94244E 22EAF7 F70045 050016868 ALM 06 1283 463678 0FFB30 FD4300 A10D92 COE3E9 AF2ADO 280C02 2D014F amp 72 WTP 1282 467133 123 3912410 78918 5020022 amp C9 EPH 06 409001 191EA0 D180AF B1A11B D70FF5 4B7242 000145 2C7A40 4B084E 38258E 0A93F7 068403 6813BB 1294A1 0E1379 72427F 0059C5 DCF2CA FFE026 199E24 1831AF 1F3454 FFA567 4B0CA5 amp 41 ALM 07 1283 476B8C OFFC42 FD4500 A10C34 BFC27E B5493D 7DE84A 36FF7D amp DA ALM 08 1283 484AA1 OFOF3E FD5700 A10C85 6DEFF7 630BEA 2ECA8F FF0004 amp D3 WTP 1282 467134 147 3912410 78918 5020023 amp D1 EPH 07 409000 191EA0 D180AF B1A11B D70FFC 827241 00FF54 376860 8209B4 38FCE3 AAEB14 08BC06 B924E7 129CA1 OCAD61 72412A FFC2C4 BB803E 006626 2AC533 1954B5 42FB87 FFA246 820D5F amp 9D ALM 09 1283 49831A OFO6BA FD4D00 A10D21 6B1798 2BACC4 1CCC36 F8FFED amp D3 ALM 10 1283 4A3140 0F186D FD5000 A10DC1 17BA55 0CF794 AB51B6 06000F amp 4F WTP 1282 467135 171 3912410 78917 5020024 amp CF EPH 10 409201 091EA0 D180AF B1A11B D70FFB E97242 000006 06598F E9FAD2 2D0F11 45B59C FBADO3 147CC7 11F7A1 0E1E37 72427C 00231C B2DB46 001A27 ED6AE7 1B720C FA5223 FFA8BA E9F011 amp B5 ALM 11 1282 4B18FE 90E825 FD1400 A10CF2 EDO7E2 02BFAA 7EA606 12002A amp 86 ALM 13 1283 4D1370 0F1B34 FD6400 A10CA5 423D1E 25448B AD34F8 FC001B amp 68 WTP 1282 467136 195 3912411 78917
76. rld may differ Delta range Small changes in range between a satellite and the receiving antenna DoD American Department of Defence DOS Disk Operating System DOP A DOP Dilution of Position is a figure which represents the purely geometrical contribution of the satellites positions to the total position error budget Low values of a DOP 1 5 mean that the calculated position should be good whilst higher DOP values indicate a greater uncertainty in the determined position Good DOP values are obtained when satellites are well spaced geometrically whilst poor values result from available satellites all being visible in similar directions When the DOP value is excessive e g gt 100 then neither stand alone nor differential positions should be used DR Dead Reckoning a means of estimating present position based on a known starting position updated by applying distance and direction of the user s movements DSR Data Set Ready serial communication handshaking DTR Data Terminal Ready serial communication handshaking ECEF Earth Centered Earth Fixed Ellipsoidal Height as defined from the Earth s centre by a reference Height ellipsoid model see Datum EMI EMS EMC Electromagnetic Interference emitted from equipment Susceptibility to interference from other equipment and Compatibility EMI EMS EPS Emergency Power Supply only for maintaining the RTC data in the RAM when the equipmen
77. ry is used an external charging circuit will be required 100R 4 DIG 3V3 CR2032 0 47F Supercap Cell DIG GN DIG GN D D Figure 9 Typical VBATT Supplies The 1K resistor is recommended at it limits current in the VBATT circuit and provides an easy way to measure the current in the VBATT signal The 100R limits the inrush current into the supercap N AVSY C Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 14 5 Over Voltage amp Reverse Polarity Protection The CW25 contains no over voltage or reverse polarity protection The CW25 should be handled as a CMOS component with full anti static handling precautions Any fault condition that results in the maximum limits being exceeded may irrepa rably damage the CW25 14 6 Reset Generation The power on reset for the CW25 is generated on board It is generated by the regulator for the RF section This signal is an active low open collector signal and is presented on the NPOR castellation If it is desired to extend the power on reset signal or provide a manual reset for the CW25 this signal can be driven from an open collector source at any time The nPOR signal of the NS3000IC to which the NPOR castellation is connected has a Schmitt trigger input This means that there are no constraints on the rise time of the NPOR signal There is a second reset signal on the CW25 the NRESET signal NRESET is also an active low open collector
78. signal This signal is generated by the NS3000IC in response to the NPOR signal It can also be generated under software con trol Asserting the NRESET signal from an external open collector source will reset the ARM9 in the NS3000IC without resetting the whole chip Generally this signal will be left open 11 7 Boot Options The CW25 has two boot modes These are selected by the state of the BOOTSEL signal when the NPOR signal goes inac tive high Normally BOOTSEL is left open so that a pull up bias in the NS3000IC will keep that signal high When BOOTSEL is high the CW25 boots from the FLASH that is internal to the NS3000IC If BOOTSEL is tied low the CW25 boots from the ROM internal to the NS3000IC This ROM has a boot loader that polls the serial ports and I C bus for boot code This mode of operation requires special user handling and should only be used in conjunction with specific applica tion notes 14 7 1 Flash Programming The CW25 contains 128k Flash memory internal to the BB25IC which hold the module firmware The Flash is reprogrammable in the field by means of a ROM boot loader utility To run the boot loader the unit must be powered up with the BSEL line set to the correct state A loader program and batch file are provided to transfer the firmware binary image file to the module To reprogram the module follow the instructions below 1 With the module powered down connect the BSEL pin to GND 2 Connect any of the CW25 serial por
79. t is powered down ENU East North Up the order of listing co ordinates Ephemeris Similar to Almanac but providing very accurate orbital data of each individual satellite and transmitted by the satellite concerned E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice Glossary continued Firmware Program resident within the receiver GDOP Geometrical Dilution of Precision Geoid The Mean Sea Level surface of the Earth Geoid Ellipsoid Difference between the Mean Sea Level and the separation mathematical model used to define a datum at the point of interest GHz Gigahertz one thousand MHz i e 10 Hz GMT Greenwich Mean Time similar to UTC GPS Global Positioning System GPS time Time standard for the GPS system seconds are synchronous with UTC Hex Denotes a number in hexadecimal format HDOP Horizontal Dilution of Precision IC Integrated Circuit ICD Interface Control Document y o Input Output IODE Issue of Data Ephemeris IRQ Interrupt Request Kalman Filter Mathematical process used to smooth out measurement errors of pseudo ranges and carrier phases of tracked satellites For example 8 states refers to filtering of position and time i e x y z and t and the rate of change of each knot Nautical mile per hour L1 The 1575 42 MHz frequency radiated by GPS satellites L band T
80. tence ranging from 1 to t inclusive Null fields within a command shall be interpreted as use current value where appropriate Null fields must be delimited by adjacent commas when they exist between two non null fields If all trailing fields after a given field are null further commas are not required Note For CW25 TIM the commands include VERS DYNA ITIM RSET INTM ILLH COMA FRQD IDNO ZONE For CW25 NAV the commands include VERS DYNA ITIM RSET INTM ILLH COMA FRQD IDNO ZONE The accuracy testing of INTM command is not yet implemented Additional commands some documented here can be enabled with custom firmware Further customization is also available Please consult the factory for details 8 3 1 PRTH lt Q R gt VERS Software Version Purpose This message Queries and Responds with the current software version information Query Format PRTHQ VERS checksum lt cr gt lt lf gt Response Acknowledge Format PRTHR VERS Build_Name Version_Number Version_Date Version_Time Serial Num BB_Releaset lt checksum gt lt cr gt lt lf gt Explanation of Parameters Build_Name Product name i e CW25 TIM or CW25 NAV Version Number Software version number Version_Date Software build date in Mmm_dd_yyyy format where Mmm is the Three character abbreviation of the month name Version_Time Software build time in hh mm ss format Serial Num Product serial number is current not implemented and always outputs Serial_Num BB Release Baseband v
81. terface The signal return path is DIG GND 4 USBP Type I O Direction Input Output Pin 30 The positive USB signal The signal return path is DIG_GND 5 USBN Type I O Direction Input Output Pin 31 The negative USB signal The signal return path is DIG_GND LED RED Type I O Direction Output Pin 8 This is a dual function signal Normally this signal is used to drive a red LED Standard software builds use this signal to indicate GPS status In special software builds this signal can be used as GPIO This signal has a 3 3V CMOS drive A series limiting resistor is required to limit output current to 5mA typically 270 ohms The signal return path is DIG_GND LED_GRN Type I O Direction Output Pin 9 This is a dual function signal Normally this signal is used to drive a green LED Standard software builds use this signal to indicate GPS status In special software builds this signal can be used as GPIO This signal has a 3 3V CMOS drive A series limiting resistor is required to limit output current to 5mA typically 270 ohms The signal return path is DIG_GND GPIO 0 PWM Type I O Direction Input Output Pin 39 Normally the GPIO 0 PWM output provides a Frequency Output that defaults to 10 MHz and is user configurable from 10 Hz to 30 MHz signal The output is enabled on power up and is steered by the GPS solution Custom software versions can also configure this pin for general I O PW
82. the duration for that command Subsequent commands may reassign an output period to sentences disabled in this way effectively re enabling the output sentence This command also supports a shortcut by means of an ALL speci fier When this is encountered the period specified is applied to all sentences An example of this is shown below where every message output on port1 will be printed at a 5 second period with the exception of the GPRMC sentence which will be output every second and the POLYT sentence which will be disabled PRTHS U1OP ALL 5 RMC 1 PLT 0 An example response string is shown below In this example all sentences are output every second except GPGSV which is output every three seconds and POLYT which is not output at all i e the sentence output is disabled PRTHR U10P GLL 1 RMC 1 VTG 1 GGA 1 GSA 1 GSV 3 PLT 0 PLP 1 PLS 1 PLI 1 0C 9 2 NMEA Configuration Set 6PRTHS UxOP The command takes the form PRTHS UxOP GLL 2 GGA 4 GSV 0 where x is a port number On the CW25 platform the port number is always between 1 and 3 inclusive The remainder of the string is of the form GLL 1 GSV 4 PLT 1 The specific contents supported are dependent on the NMEA sentences supported by the system Only the settings which are to be altered need to be listed A NMEA checksum of the form 4D is appended to the output string The list of currently supported NMEA sentences are as shown above for the Query command To turn a
83. timated N Invalid Not Valid cs Message checksum in hexadecimal 8 2 1 7 GPZDA UTC Time and Date This message transfers UTC Time and Date Since the latency of preparing and transferring the message is vari able and the time does not refer to a particular position fix the seconds precision is reduced to 2 decimal places GPZDA hhmmss sss dd mm yyyy Int Unsigned cs Name Description GPZDA NMEA sentence header Time and Date hhmmss sss UTC Time in hours minutes seconds dd UTC day mm UTC month yyyy UTC year Int Unsigned Local zone hours Int Unsigned Local zone minutes kph Speed over ground kph K Kilometers per hour fixed field cs Message checksum in hexadecimal Proprietary NMEA Messages 8 2 1 8 POLYT Time of Day POLYT hhmmss sss ddmmyy UTC TOW week GPS TOW CIk B Clk_D PG BLANK BLANK BLANK BLANK cs Name Description POLYT Navsync Proprietary NMEA sentence header Position Data hhmmss sss UTC Time in hours minutes seconds and decimal seconds format ddmmyy Date in day month year format UTC TOW UTC Time of Week seconds with microseconds resolution week GPS week number continues beyond 1023 GPS TOW GPS Time of Week seconds with microseconds resolution CIk B Receiver clock Bias nanoseconds CIk D Receiver clock Drift nanoseconds second PG 1PPS Granularity nanoseconds cs Message checksum in hexadecimal
84. ts to COM1 of your PC 3 Power the unit up The CW25 should start by outputting a stream of Z characters at 38400 baud You might like to check this out via a terminal program If after about 20 seconds the re programming step 4 hasn t started the stream of Z s will stop and the existing CW25 firmware will run 4 Just after the unit has been powered and while the Z s are being run download bat batch file from a Console window You can edit this batch file to use a PC port other than COM if you prefer You should see CW25 FILE Up DownLoader ver 1 0 C NavSync Inc 2003 loader loader hex baud rate 38400 comm comi Addr 0x060000 binary file CW25 bin debug mode 2 Reset the board and then ENTER key 5 Hit Enter and you will see Start waiting for BootRom Then after a few seconds you should then see BootRom loader found After about 7 10 seconds you should see S Record loader sent Then you will see a stream of dots going across the screen as the firmware is being downloaded Once the download has finished you will see Image download Passed Process finished If errors are encountered during the upgrade procedure simply reset the module and start the procedure again Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice Appendix 1 Glossary 2D Two dimensional 3D Three dimensional i e including altitude AGC Automatic Gain Control Al
85. ubject to change without notice 12 Time Pulse Interface The time pulse interface outputs a precise pulse with respect to UTC time Typically this is a 1pps signal The time pulse is output on 1PPS port pin 38 The signal is active high with the rising edge synchronous 30ns to the UTC second and has a width of 100us Alternate pulse widths may be accommodated with custom firmware Please consult the factory For the 1pps to be valid the receiver must have a valid position fix and have received the UTC GPS separation parameter downloaded from the satellite this may take up to 12 5 minutes from a cold start Risetime Pulsewidth c gt Pulse width 100 Sec Risetime maximum 10 nSec 2 metre std lead Synch to UTC rising edge 30 nSec GDOP 3 0 no S A Output 3 3V Volt nominal Vhigh gt 3 0 v at 6mA out Viow lt 0 33 v at 6mA sink 13 Frequency Output The CW25 is capable of producing a user select frequency The frequency is output on GPIO 0 port pin 39 The frequency is configured using the FRQD command as detailed in section 8 3 10 The frequency is only valid when the receiver has a valid 2D position fix or better Risetime Pulsewidth Pulse width 25ns minimum CW25 NAV 16 67ns minimum CW25 TIM Duty Cycle 50 50 Risetime maximum 10 ns 2 meter std lead Output 3 3V Volt nominal Vnign gt 3 0 v at 6mA out Viow lt 0 33 V at 6mA sink E
86. ut notice 4 SIGNAL DESCRIPTION continued 4 2 RF Signals RF_IN Type RF Direction Input Pin 24 The RF input signal This attaches to the GPS antenna Standard RF design rules must be used when tracking to this signal This signal has an RF blocked connection to the ANT_SUPPLY signal This is the same signal presented on the RF connector on the CW25 Only one antenna connection should be made If the RF connector is to be used then there should be no connection even an unconnected pad to this castellation TRIM Type RF Direction Input Pin 12 This signal trims the output frequency of the VCTCXO This signal is normally left open When floating this signal is biased to the control voltage of the VCTCXO Any noise injected into this signal will severely compromise the performance of the CW25 This signal should only be used in conjunction with specific application notes EXT_CLK Type RF Direction Input Pin 7 This input is the external clock input This signal is to be used only in special builds of the CS25 that are not fitted with an internal VCTCXO For the normal build containing the VCTCXO do not connect this input The external clock is a 20 MHz clipped sinewave input with an amplitude between 1V and 3V peak to peak The return path for this signal is RF GND 4 3 Emulation Test Signals TDI Type Test Direction Input Pin 14 The Test Data In signal This is the standard JTAG test data input
87. ved by the U S Govern ment E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 2 SPECIFICATION 2 1 Performance CW25 GPS RECEIVER SPECIFICATIONS Physical Module dimensions 25mm D x 27mm W x 4 2mm H Supply voltages 3V3 Digital I O 3V3 RF 1V8 Core option 3V Standby Battery Operating Temp 30 C to 85 C Storage Temp 40 C to 85 C Humidity 5 to 95 non condensing Max Velocity Altitude 515ms 18 000m increased rating version available subject to export license Max Acceleration Jerk 4g 1gs sustained for less than 5 seconds Sensitivity Acquisition with network assist 185dBW Tracking 186dBW Acquisition Stand Alone 173dBW Acquisition Hot Start with network assist Outdoor lt 2s Time Indoor 178dBW lt 5s Stand Alone Outdoor Cold lt 45s Warm lt 38s Hot lt 5s Re acquisition 1s 90 confidence Accuracy Position Outdoor Indoor bm rms 50m rms Velocity 0 05ms Latency 200ms Raw Measurement Accuracy Pseudorange lt 0 3m rms Carrier phase 5mm rms Tracking Code and carrier coherent Power 1 fix per second 0 6W typically Coma Mode Current 10mA RF3V3 DIG3V3 Standby Current VBATT 1 5pA Interfaces Serial 3 UART ports CMOS levels Multi function I O 1PPS Frequency Output available on GPIO 0 Event Counter Timer Input Up to 4 x GPIO multi function 2 x LED Status Drive lC External Clock on spe
88. ween the and amp characters in hexadecimal E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 11 1 3 KLB Klobuchar lonospheric Parameters Message This message is output approximately once every 16 seconds ZKLB a0 a1 a2 a3 bO b1 b2 b3 amp cs KLB 5 2 1 2 38 3 1 4 amp BA Name Description KLB GPS Navigation Message Klobuchar ionospheric delay correction model parameters See ICD GPS 200 for full details a0 a x 2 99 seconds a1 a x 227 seconds per semicircle a2 a x29 seconds per semicircle a3 a x 2 seconds per semicircle bO b x 2 seconds b1 b x 24 seconds per semicircle b2 b x 216 seconds per semicircle b3 b x 216 seconds per semicircle cs 8 bit accumulative checksum of all bytes in between the and amp characters in hexadecimal 11 1 4 UCP UTC Correction Parameters Message This message is output approximately once every 16 seconds ZUCP A1 AO Tot WNt atLS WNLSF DN dtLSF amp cs UCP 20 8 15 3 13 222 5 13 amp 68 Name Description UCP GPS Navigation Message UTC Correction model Parameters See ICD GPS 200 for full details Al A X29 seconds AO A x 2 0 seconds second Tot Tot x2 seconds WNt WN x 1 weeks DiLS Dt s x 1 seconds WNLSF WN sF x1 weeks DN DN x1 days DtLSF Dt s x 1 seconds cs 8 bit accumulat
89. y The frequency in Megahertz that the receiver will output CW25 TIM defaults to 10 MHz 30 MHz maximum CW25 NAV defaults to 0 MHz disabled 20 MHz maximum e g for 10kHz 0 010 O switch digital frequency off E Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice 8 3 9 PRTH lt Q S R gt MMSV MIN amp MAX SATELLITES FOR A POSITION SOLUTION Purpose This message Sets Queries and Responds to the minimum and maximum number of satellites the receiver will use for a position solution Increasing the minimum number of satellites will improve the accuracy achieved when sufficient satellites are available but may reduce the time when a solution can be produced Reducing the maximum number of satellites may reduce the accuracy of the position solution but will decrease the amount of processing power required for the solution Note that setting the Maximum satellites to less than 4 will prevent the receiver from performing a 3D position solution Likewise setting the minimum number of satellites greater than 3 will prevent the receiver performing a 2 D altitude fixed solution The maximum must be greater than or equal to the minimum number of satellites Query Format PRTHQ MMSV checksum lt cr gt lt lf gt Set Format PRTHS MMSV min_NSV max_NSV checksum lt cr gt lt lf gt Response Acknowledge Format PRTHR MMSV min_NSV max_NSV lt checksum gt lt cr gt lt lf gt Explanation of
90. ype Power Direction Input Output Pins 18 23 25 The RF input ground connect to common ground This is the return path for the RF 3V3 supply and the ground for the antenna feed The RF GND must be tied to the DIG GND externally to the CW25 RFV OUT Type Power Direction Output Pin 17 The output from the LDO regulator 3 0V that is powered by the RF 3V3 signal This supplies the power to the RF subsystem of the CW25 This may also be used to power external RF components but care must be taken not to inject noise onto this signal No more than an additional 30mA may be taken from this signal by external circuitry ANT SUPPLY Type Power Direction Input Pin 26 The antenna supply voltage This may be used to supply power to the RF IN signal for use by an active antenna The maximum voltage should not exceed 15V and the current should be limited to 50mA to prevent damage to the CW25 DIG 3V3 Type Power Direction Input Pin 36 The digital supply input This 3 3V 10 input supplies the I O ring of the BB25IC chip and the LDO regulator in the digital section of the CW25 It is important that this supply is well filtered with no more that 50mV peak to peak noise with respect to DIG GND DIG 1V8 Type Power Direction Input Pin 34 The 1 8V 5 digital core supply for the BB25IC This is normally connected directly to the 1V8 OUT signal However if an external 1 8V 5 is available a lower overall system power consumption may b

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