Design
Design
the GPS antenna
The data transmitted from the GPS antenna to the RTI control module consists of signals received from GPS satellites.
There is a signal booster (antenna amplifier) integrated in the GPS antenna. The signal is strengthened before it is transmitted to the GPS receiver which is integrated in the RTI unit. The GPS also adapts the impedance of the signal.
The RTI system and the GPS antenna require contact with at least three satellites to be able to calculate the position of the car. The RTI system can communicate with up to eight satellites at the same time.
The position calculated from the GPS satellites is accurate to within +/- 30 meters.
View the GPS information under system settings to check how many satellites are available.
The power supply is from the RTI control module. The power supply uses the same high frequency wiring as the GPS information that is sent to the RTI unit.
The GPS antenna is located in the parcel shelf in S80 and S60 models. In V70 and V70XC models it is located in the dashboard.
Note! If there is no GPS signal, the signal should be checked outside. The signal may be blocked if the car is indoors. Large objects on the parcel shelf or tinted rear windshields may also be the cause.
TV receiver
The role of the TV receiver is to manage the incoming TV signals from local TV transmitters.
There are three models of the TV receiver:
- One for Europe (PAL)
- One for U.S.A. (NTSC), only applies to the S80 Executive
- One for Japan (NTSC).
The European TV receiver can handle three different PAL systems. The menu system on the TV receiver is used to change the PAL system settings. See the RTI manual for further information.
The TV receiver sends the received TV signals on a serial bus (Melbus) to the RTI system. The RTI system handles the incoming signals and sends them to the display screen.
The TV receiver transmits the TV sound on a serial bus (Melbus) to the audio module via the RTI unit.
Station settings, color, TV picture size and the screen contrast are set using the audio module or the remote control.
The TV receiver is located in the left section of the cargo compartment in the S80 and S60. In V70 and V70XC models it is located behind the rear seat.
RTI control module
The role of the RTI control module is to calculate the position of the car based on the signals it receives from the GPS antenna, the speed signal from the central electronic module, the gear position and the gyro. The RTI system then works out a route for the selected destination.
There are two models of the RTI system, one old and one new version.
The older system has two units, the RTI control unit and the CD changer. In the new system the CD changer has been replaced by a DVD player which is integrated with the RTI control module.
There is an integrated three dimensional piezo electrical gyro in the RTI control module. This manages data about the movements of the car, such as whether any turnings are made.
Data transmitted on the CAN to the RTI unit from different nodes is:
- vehicle speed
- wheel rotation counter
- back-up (reverse) gear position
- signals from the steering wheel controls
- radio mute
- background lighting.
Gyro and wheel rotation counters are used to calculate the position of the car for shorter periods, if communication with the GPS satellites is lost in a tunnel for example or to assist when there is no GPS signal.
Used in conjunction with map matching, GPS navigation, the gyro and the speed signal, the position can be calculated to an accuracy of +/- 10 meters from the position indicated on the screen.
The traffic message channel (TMC) receiver is integrated in the RTI unit. TMC is a standardized code system for traffic messages such as road works. The Japanese equivalent is called FM multiplex.
There is no traffic information system in the USA.
The TMC antenna is located in the right-hand section of the rear bumper.
The control module is located on the left-hand side of the cargo compartment.
The RTI (road traffic information) control module can be diagnosed.
Display
There are two sizes of display screen. There is a 6.5 wide screen LCD screen and a 5 LCD screen.
All signal information to the screen is from the RTI control module.
The screen has an infra red eye above it which is used for communication with the remote control.
The menu system for the screen can be controlled using the RTI buttons on the reverse of the steering wheel or using the remote control.
The screen is positioned in the middle of the dashboard.
CD changer
A six disc CD changer is used together with the RTI control module on the older RTI system.
This unit only handles CD discs with map information, not music CDs.
The discs contain information about road networks, streets, voice guiding and the software required for the system to function. The CD changer communicates with the RTI unit on serial buses (Melbus).
Remote control
There is a dedicated remote control for the RTI unit. The function of the remote control is the same as the steering wheel buttons.
There is also a separate remote control for the TV receiver which can be used to store and change TV stations, the color, the size of the picture and the contrast on the screen.