Telemetry Systems

Wireless communication between VBOX products often forms an essential part of our customer’s testing requirements. This may take the form of a Bluetooth connection to a tablet PC for live data output; for transmitting DGPS correction messages to a roving VBOX unit to obtain high positional accuracy; or for the exchange of GPS measurements from one VBOX to another in open-road testing during the development of a vehicle’s safety systems.

When choosing the correct telemetry system it is often necessary to speak to your VBOX distributor to determine which units will best suit your application – both in terms of range and bandwidth, and local laws governing radio transmission.  

DGNSS Base Stations

Posted in Telemetry Systems

Overview

Base-StationThe RACELOGIC DGNSS Base Station is designed to improve positional accuracy of VBOX units and other compatible GPS/ GLONASS systems by calculating and transmitting differential correction data.

By programming the Base Station with a known position, it is able to accurately monitor the difference between its programmed position and the position that it is receiving via GPS/GLONASS.

The difference is then transmitted via radio to allow a remote GPS system to correct its position.

The differential correction message can be broadcasted in RTCM, CMR or proprietary RTK formats using an internal or mast mounted radio modem transmitter.

Depending on the type of Base Station and roving unit used, position accuracies of up to 2cm 95% CEP are available.

VBOX Telemetry Radios

Posted in Telemetry Systems

Overview

Telemetry-moduleThe telemetry modules from Racelogic are radio modems for use with the VBOX range. Each module contains a high power radio modem capable of transmitting and receiving RS232 serial data.

RACELOGIC radios are used for three main purposes:

  • To transmit and receive differential correction information (DGPS) from a RACELOGIC Base Station for local position correction.
  • To transmit 'ADAS' data between 2-3 VBOX units, for live vehicle separation measurement.
  • To transmit VBOX serial data from a remote unit to a laptop PC at a maximum rate of 20Hz.

There are a variety of telemetry systems available, employing a range of frequencies. Which version is used depends on the range over which they need to be employed, and local radio licensing regulations.

  • 869 MHz Radios
  • 915 MHz Radios
  • 2.4 GHz Radios
  • Variable Frequency Radios

For advice as to the most suitable type for your application it is best to contact us to discuss your requirements.

Each radio is supplied with a magnetic mounting antenna, and is connected simply to the VBOX via one cable. See radio overview for more info.

VBOX Bluetooth Module

Posted in Telemetry Systems

Overview

Bluetooth-moduleThe VBOX Bluetooth module (RLVBBT01) is a general purpose Bluetooth adapter, designed as an alternative to using a hard-wired serial connection between the VBOX and either a Q5 tablet (recommended) or a Laptop PC equipped with a Bluetooth interface.

The Bluetooth module has a range of up to 30m, allowing the user to place the VBOX in a safe, dry and convenient location and facilitating the free use of the Q5 display, either by hand or mounted, without any cabling restrictions.

The RLVBBT01 offers high speed serial communications at 115K baud rate, ensuring full data capture and transfer. It has minimal power consumption, resulting in insignificant drain on the VBOX power source – particularly useful when using a VBOX battery pack, in addition to 13 standard GPS channels.

VBOX NTRIP Modem

Posted in Telemetry Systems

NTRIP Modem RLACS250The VBOX NTRIP Modem allows a VBOX 3i RTK to receive positional correction data via Network RTK, without having to use a VBOX Base Station.

Correction messages received via the RTK network can be an advantage if testing is conducted tens of kilometres away from the base station, over large changes in elevation or where topographical obstacles could get in the way.

If RTK coverage is available, the VBOX NTRIP Modem allows for vehicle testing that requires high positional accuracy – such as when validating critical safety systems like AEB/ACC - to be conducted where a VBOX Base Station cannot be deployed.

What is Network RTK?

Network RTK utilises one or more Continuous Operating Reference Stations (CORS) to provide RTK data to a GNSS Rover, usually via mobile internet.

The most common method of Network RTK involves a two-way communication link which allows the roving vehicle to send its position to a service provider that is monitoring satellite observations from several reference stations around a country.

What is NTRIP?

Most network RTK systems are internet based and utilise a protocol called NTRIP (Networked Transport of RTCM via Internet Protocol). A constant internet connection is required to receive corrections, which can be done via a cellular modem, such as VBOX NTRIP, or a smart phone.

How does it work?

The VBOX NTRIP Modem enables the roving VBOX unit to send its position to the stations within the network – just as it would to a single VBOX Base Station. The NTRIP service provider will then calculate the appropriate corrections for the VBOX’s location based on the data from nearby reference stations. This correction information is then returned to the VBOX in the same RTCM format as is used for a single fixed base station.

In order to use this type of correction you have to register and subscribe to a cellular data plan with your local NTRIP provider, such as Topnet in the UK and Germany, Swepos in Sweden or Unavco in the USA.

 

RTK network

Please see RACELOGIC Support for information on modem setup and configuration.

Specification

Power Input: 7 V DC to 24 V DC
Power Consumption: 12 V DC: 75 mA; 18 V DC: 50 mA
Antenna Connection: FME M 50 Ω antenna connector
Size (L x W x H): 76 mm x 56 mm x 25 mm
Weight: 100 g (2.5 oz)
Extended Temperature Range: -40 °C to +75 °C
Bands: Quad-Band (850/9000/1800/1900 MHz), Five Bands UMTS (WCDMA/FDD) 800, 850, 900, 1900 and 2100 MHz

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