Gems LDS4, Руководство по эксплуатации, Страница: 45 / 71

39 Display Configuration
© 2009 General Engine Management Systems Ltd.
By default, GPS support is turned off. To activate GPS support, select either Serial or CAN in the
GPS Source box.
Serial GPS Requirements
· The GPS unit must be connected to the Serial Rx1 pin on the LDS4.
· The GPS unit must be sending out a standard NMEA data stream at 4800 baud.
·
The $GPGGA and $GPRMC sentences must be implemented.
CAN GPS Requirements
·
The message IDs are user configurable and can be standard or extended.
· There must be a message containing longitude and latitude (Long/Lat CAN); bytes 0 to 3 of the
message must be latitude; bytes 4 to 7 must be longitude. Both must be a signed 32 bit big
endian integer in the form of Lat * 100000 or Long * 100000.
· There must be a message containing heading, speed and sat count (Hdg/Spd CAN). The first
word must be Heading at 0.01 deg/bit. The Second word must be speed in 0.01kph/bit and the
3rd word must be satellite count.
Once setup, several new channels will be created for display on the screen:
·
GPS Heading - The heading in degrees.
· GPS Latitude - The latitude in minutes and fractions of minutes. Negative is South.
· GPS Longitude - The longitude in minutes and fractions of minutes. Negative is East.
·
GPS Sats - The number of satellites seen by the GPS receiver.
· GPS Speed - The speed in kph.
7.4.1 Using Onboard Sector Analysis
Onboard Sector Analysis (OSA) allows the user to use GPS to simulate split beacons around the
track. these can then be used to generate a delta of the current lap to the fastest lap.
To use OSA, it is first necessary to setup the GPS system. All that is then needed is to specify the
location of the desired split points in longitude and latitude. The easiest way to do this is to
display GPS Longitude and GPS Latitude on the screen and drive the circuit, noting the
longitude and latitude at the desired points.
Once the data has been noted, go to Setup | GPS and set the split count to the number of splits
required. For each split, enter a latitude and longitude. Finally, specify the Tolerance which is how
close the current latitude and longitude need to be to the split values before the display
determines that the split has been reached. Smaller numbers will give greater accuracy but may