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PixSoft Inc. Tel: +1.204.885.4936 Fax: +1.204.895.4173 E-mail: [email protected] 

 
 
 
 
 

Ultra Low Power, High Sensitivity   

 

GPS-NX01 Receiver

 

User Guide   

 
 
 
 
 
 
 

Summary of Contents for GPS-NX01

Page 1: ... PixSoft Inc Tel 1 204 885 4936 Fax 1 204 895 4173 E mail sales stargps ca 1 Ultra Low Power High Sensitivity GPS NX01 Receiver User Guide ...

Page 2: ...rnal clock and memory recharges during normal operation One full duplex serial port with selectable baud rates and NMEA messages Supports standard NMEA 0183 Meade LX200 and Celestron NexStar communication protocols Automatically detects telescope type Meade Celestron or none Switches to standard NMEA output after 30 seconds if no telescope is detected LED power indicator blinks to indicate receive...

Page 3: ...des a low noise high gain active antenna in a unique waterproof case Simply connect the PS 2 female connector to one of the optional accessories and link to either your notebook PC PDA telescope or other device For telescope adapter cables refer to www stargps ca cables htm other cables are listed and described below ...

Page 4: ...ack 2 2 GPS DB9 Cable Mini Din Female and PS 2 male connector Cable Length To GPS NX01 1 meter RS 232 to PS 2 45 cm Mini Din Female connector function definition PS 2 composite connector function definition to PC Pin Signal 1 Tx RS 232 2 5VDC 3 Tx TTL 4 GND 5 Rx TTL 6 Rx RS 232 Pin Signal 1 N C 2 TX 3 RX 4 N C 5 GND 6 N C 7 N C 8 N C 9 N C Pin Signal 1 5VDC 2 N C 3 N C 4 GND 5 N C 6 N C ...

Page 5: ... to start using your own navigating software 1 Click Start menu select Settings then enter Control Panel 2 After entering Control Panel select System 3 Select Device Manager 4 Find the Connect Port and check the Virtual COM Port which was created by the USB driver Please note that the Virtual COM Port number might be different from every computer Before using navigating software please confirm the...

Page 6: ...conds the GPS LED will blink rapidly for 5 seconds and then NMEA output will begin as shown in the above table 0 none 1 every second 3 every three seconds NMEA Extensions The software is capable of supporting the following NMEA extensions NMEA Message Prefix Format Direction PNMRX100 Set serial port parameters In PNMRX101 Navigation initialization In PNMRX103 NMEA message rate control In PNMRX104 ...

Page 7: ...retation of subsequent fields The tables below indicate the maximum and minimum widths of the fields to allow for buffer size allocation GPGGA This message transfers global positioning system fix data The GPGGA message structure is shown below Field Format Min chars Max chars Notes Message ID GPGGA 6 6 GGA protocol header UTC Time hhmmss sss 2 2 2 3 2 2 2 3 Fix time to 1ms accuracy Latitude float ...

Page 8: ...ata Valid V Data invalid Mode Indicator Char 1 1 A Autonomous Checksum xx 0 3 3 2 digits Message terminator CR LF 2 2 ASCII 13 ASCII 10 GPGSA This message transfers DOP and active satellites information The GPGSA message structure is shown below Field Format Min chars Max chars Notes Message ID GPGSA 6 6 GSA protocol header Mode Char 1 1 M Manual forced to operate in selected mode A Automatic swit...

Page 9: ... Int 2 2 Satellite vehicle 1 Elevation Int 1 3 Elevation of satellite in degrees Azimuth Int 1 3 Azimuth of satellite in degrees SNR Int 0 1 2 Signal to noise ration in dBHz null if the sv is not in tracking Satellite Id Int 2 2 Satellite vehicle 2 Elevation Int 1 3 Elevation of satellite in degrees Azimuth Int 1 3 Azimuth of satellite in degrees SNR Int 0 1 2 Signal to noise ration in dBHz null i...

Page 10: ...oat 1 1 3 2 Course over ground in degrees Date ddmmyy 2 2 2 2 2 2 Current date Magnetic variation Blank 0 0 Not used E W indicator Blank 0 0 Not used Mode Char 1 1 A Autonomous Checksum xx 0 3 3 2 digits Message terminator CR LF 2 2 ASCII 13 ASCII 10 GPVTG This message transfers Velocity course over ground and ground speed The GPVTG message format is shown below Field Format Min chars Max chars No...

Page 11: ...igned 2 2 Checksum xx 0 3 3 2 digits Message terminator CR LF 2 2 ASCII 13 ASCII 10 Extensions Specification For all PNMRX messages it is possible to configure an alternative string to replace the NMRX part the node always responds to the PNMRX strings and can be configured to generate and respond to the alternative string PNMRX100 Set serial port mode This message is sent to control the serial co...

Page 12: ...al clock bias used by the system A cold start is necessary in order to use this value Time of week Int 1 6 Offset from start of week in seconds Week number Int 1 4 GPS week number Channel count Int 1 2 Maximum number of TM to be used Min 12 max 16 Checksum xx 0 3 3 2 digits Message terminator CR LF 2 2 ASCII 13 ASCII 10 If used all three X Y and Z components of the ECEF position must be provided o...

Page 13: ...xceed 80 characters it is divided into 2 messages This message is supported also in a variable length format where only the necessary fields are used Field Format Min chars Max chars Notes Message ID PNMRX103 8 8 PNMRX103 protocol header Mask ID Int 3 3 Mask identifier possibilities are GGA GLL GSA GSV RMC VTG ZDA ALL applies to all messages Mask value Int 1 1 Output rate in seconds 0 paused Mask ...

Page 14: ...nutes under dev E W Indicator Char 1 1 E east or W west under dev Altitude Int 1 6 Altitude above MSL in meters Clock offset Int 0 1 6 Clock offset of GPS receiver This changes the clock bias stored in the settings not the actual clock bias used by the system A cold start is necessary in order to use this value Time of week Int 1 6 Offset from start of week in seconds under dev Week number Int 1 4...

Page 15: ...X106 protocol header Correction Mode Unsigned 1 1 If 1 apply EGM96 geoid correction warning should be applied only when Map Datum is equal to 216 If 0 there is no EGM96 geoid correction Map Datum Int 0 1 3 Reference number of the appropriate map datum to apply 0 218 Map datum from internal table 500 User defined Datum Dx Int 0 1 5 X offset in meters 9999 to 9999 Dy Int 0 1 5 Y offset in meters 999...

Page 16: ... it is divided into 2 messages This message is supported also in a variable length format where only the necessary fields are used Field Format Min chars Max chars Notes Message ID PNMRX107 8 8 PNMRX107 protocol header Message code Char 3 3 Determines which message is being configured 300 PNMRX300 Almanac Data 301 PNMRX301 Ephemeris Data 302 PNMRX302 lonospheric corrections 303 PNMRX303 UTC Time 3...

Page 17: ...he messages can be changed by means of the PNMRX103 message This message is supported also in a variable length format where only the necessary fields are used Field Format Min chars Max chars Notes Message ID PNMRX108 6 8 PNMRX108 protocol header Mask ID Int 3 3 Mask identifier possibilities are GGA GLL GSA GSV RMC VTG ZDA Mask ID Int 3 3 Mask Identifier Checksum xx 0 3 3 2 digits Message termina...

Page 18: ...value for mask dependent on the preceding field see below Mask ID Int 2 2 Mask identifier Value Variant 1 8 New value for mask dependent on the preceding field Checksum xx 0 3 3 2 digits Message terminator CR LF 2 2 ASCII 13 ASCII 10 PNMRX110 Mask Field interpretation Mask Id mask format width units 0 Local Time Zone Int unsigned 2 2 Hours Miuntes 1 Maximum PDOP 1 Unsigned 4 x10 0 100 2 Maximum HD...

Page 19: ...PNMRX111 protocol header Invalidate parameter Integer OR String 1 7 If integer the bit field have the following meaning the action described is executed if the bit is 1 Field Action 0 Reload settings from Flash 1 Clear almanac data and don t load if from flash 2 Clear Ephemeris data 3 Clear lonospheric and tropospheric corrections 4 Invalidate stored position 5 Invalidate stored time 6 Copy oscill...

Page 20: ... low power mode with 5 seconds off time between 2 fixes PNMRX113 GPS Core Activity Control This message is used to disable GPS Core activities data extraction and fix generation on the node The goal of this message is to disable these two functions when they need to be overwritten by external values for test purpose A reset message must be set after the PNMRX113 in order to resume operation For in...

Page 21: ...e position solution The appropriate scaling factors are included in the table There is 1 message for each satellite for which data is available When transmitted these messages are generated in ascending order of SV Id when being sent to the node these can be sent in any order each message is individually interpreted and processed Field Format width scale Notes Message ID PNMRX300 8 PNMRX300 protoc...

Page 22: ...em the contents of these frames reflects the contents of the appropriate subframes 1 2 3 transmitted from the SV s When transmitted these messages are generated in ascending order of SV Id and sequence number when being sent to the node these can be sent in any order provided that the 3 messages for any individual satellite are grouped together each message is individually interpreted and after a ...

Page 23: ... 2 8 bits lower 8 bits of matching iodc Crs Hex 4 2 5 Meters 16 bit signed integer Motion difference n Hex 4 2 43 Semi circles sec 16 bit signed integer Mean anomaly Hex 8 2 31 Semi circles 32 bit signed integer Cuc Hex 4 2 29 Radian s 16 bit signed integer E Hex 8 2 33 32 bit signed integer Cuc Hex 4 2 29 Radian s 16 bit signed integer Root A Hex 8 2 19 Meters 1 4 32 bit signed integer Toe Hex 4 ...

Page 24: ...Crc Hex 4 2 5 Meters 16 bit signed integer Perigree Hex 8 2 31 Semi circles 32 bit signed integer Omega dot Hex 6 2 43 Semi circles sec 24 bit signed integer Iode Hex 2 Lower 8 bits of matching iodc I dot Hex 4 2 43 Semi circles sec 14 bit signed integer Checksum xx 0 3 2 digits Message terminator CR LF 2 ASCII 13 ASCII 10 PNMRX302 Ionospheric correction Field Format width scale units Notes Messag...

Page 25: ... reference week number WNlsf Hex 2 Week number at which the leap second becomes effective DN Hex 2 Day number B2 Delta t LSF Hex 2 Delta time due to leap seconds if leap second is ini the past NumBlocks Hex 2 Number of 20 year blocks TimeOffset Hex 2 Time offset for current time zone Checksum xx 0 3 2 digits Message terminator CR LF 2 ASCII 13 ASCII 10 PNMRX304 GPS Constellation Health Field Forma...

Page 26: ... GPS PNMRX603 Settings report By sending the PNMRX603 00 string to the receiver the current value of the settings is output The content of settings is split into 4 messages PNMRX603 message 0 Field Format Min chars Max chars Notes Message ID PNMRX603 8 8 PNMRX603 protocol header Message Nb Int 1 1 0 Message Sequence 7 times 7xInt 1 1 Message Sequence Message Delay 7 times 7xInt 1 1 Message Delay N...

Page 27: ...A3 Hex 2 2 Ionospheric correction a 3 coefficient Ionospheric Data B0 Hex 2 2 Ionospheric correction ß 0 coefficient Ionospheric Data B1 Hex 2 2 Ionospheric correction ß 1 coefficient Ionospheric Data B2 Hex 2 2 Ionospheric correction ß 2 coefficient Ionospheric Data B3 Hex 2 2 Ionospheric correction ß 3 coefficient Ionospheric Data Valid Hex 1 1 Ionospheric Data Valid If 0 the data are invalid Nu...

Page 28: ... CNO Float Min Elevation Float Max TM Int 2 2 Max Sv for fix Int 2 2 Checksum xx 0 3 3 2 digits Message terminator CR LF 2 2 ASCII 13 ASCII 10 PNMRX603 message 3 Field Format Min chars Max chars Notes Message ID PNMRX603 8 8 PNMRX603 protocol header Message Nb Int 1 1 3 Acq threshold 1 Int 3 8 Acq threshold 2 Int 3 8 Noise floor Int 3 8 Kalman Mode Hex 1 1 Default altitude Int 1 8 Checksum xx 0 3 ...

Page 29: ...eoid correction Map Datum Int 1 8 Reference number of the appropriate map datum to apply Dx Int 1 8 x offset in meters Dy Int 1 8 y offset in meters Dz Int 1 8 z offset in meters Inverse flatness Int 1 8 Inverse flatness of reference geode Major axis Int 1 8 Semi major axis of reference geode Checksum xx 0 3 3 2 digits Message terminator CR LF 2 2 ASCII 13 ASCII 10 Example PNMRX603 xx Display the ...

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