Frequently Asked Questions

How can I get more positional accuracy?

The wide area systems only improve the positional accuracy by a small amount. To get a significant improvement in positional accuracy, you will need to set up your own local Base Station. A local Base Station is a portable unit that will transmit local DGPS corrections via radio over short distances. There are currently three levels of accuracy improvement available with VBOX products when using a Base Station:

• 40 cm RTCM available to all VBOXII and VBOXIII products.
• 20cm proprietary correction only available to upgraded VBOXIIS and VBOXIISX units.
• 2 cm RTK proprietary correction only available on RTK enabled VBOXIII units.

	WAAS/EGNOS DGPS	40cm DGPS Base Station 2 or 3	20cm DGPS Base Station 2 only	RTK Base Station 3G only
VBOX Data Loggers
VBOX Mini
VBOX Lite
VBOX II DCF
VBOX IIS
VBOX IISX (10Hz)
VBOX IISX (20Hz)
VBOX IISL
VBOX 3i
VBOX 3 R10G10
VBOX Speed Sensors
VBOX 5Hz Speed Sensor
VBOX 10Hz Speed Sensor
VBOX 20Hz Speed Sensor
VBOX 100Hz Speed Sensor

Key:	= Compatible
	= Compatible with upgrade
	= Not compatible

How does Interpolation work?

Interpolation of the velocity data is done in data processing between the sample points to increase the accuracy of measured data.

For example during an 80kph deceleration the point at which the vehicle crosses 80 Km/h may be between two measured samples, i.e. 80.127 and 79.738. Over such a small period of time as one sample it can be assumed that the deceleration or acceleration is linear, and therefore the measurement in time of where the 80km/h point was crossed is more accurately measured by interpolating between measured samples. This is used to calculate the exact time the vehicle was at 80km/h.

Note that no vehicle is dynamic enough to exhibit any behaviour that cannot be assumed to be anything but linear between the normal time periods of 20-100hz VBOX samples.

How accurate is VBOX when measuring position?

The standard positional accuracy of VBOX’s is 3M 95% CEP for Longitude and Latitude.

The height accuracy is 6M 95% CEP.
CEP = circle error probable.
95% CEP means 95% of the time the position readings will within a circle of diameter 3M of the true position. This error is due to the changing state of the ionosphere, constantly changing the time taken for the satellite signals to reach the earth, see GPS Errors and Noise.

The accuracy of the positional and height data can be improved using different types of Differential GPS correction methods, see Differential GPS.

See also
GPS Errors and Noise
Differential GPS

How accurate is VBOX when measuring velocity?

The velocity accuracy of all VBOX’s is 0.1km/h averaged over 4 samples. This applies to the 2D course over ground velocity.

The vertical velocity is harder to resolve and as such has an accuracy of 0.2km/h averaged over 4 samples.

These accuracies are for a VBOX used in open environments with the antenna placed to avoid multipath signal noise.

How accurate is VBOX when measuring distance?

Distance accuracy is 0.05% (

Distance is calculated by integrating velocity, and as such it is a relative distance. VBOX does not use GPS position to calculate distance as this is far too inaccurate.

What is the model of the Earth used by VBOX's?

The Geodetic datum or model of the earth used by VBOX GPS engines is WGS84.

This is a recognised standard model of the shape of the earth that is used to calculate heights above sea level at all places on the Earth.

Referencing geodetic coordinates to the wrong datum can result in position errors of hundreds of meters. Different nations and agencies use different datums as the basis for coordinate systems used to identify positions in geographic information systems, precise positioning systems, and navigation systems.

The diversity of datums in use today and the technological advancements that have made possible global positioning measurements with submeter accuracies requires careful datum selection and careful conversion between coordinates in different datums.

How do you verify the Brake distance accuracy?

We quote brake distance accuracy as follows:

VBOXIIDCF +/20cm
VBOXIIS +/10cm
VBOXIII +/5cm

We verify this by using a stationary reflective target which gives an input into the brake trigger channel on a VBOX. The vehicle under test is then driven past the light barrier before braking to zero. We can then measure the distance between the vehicle and the light barrier using conventional means and then compare this to the output of the VBOX.

How does the Brake trigger correction work?

At 100kmh a vehicle will travel 27.8cm per 100Hz VBOX sample. That means we have to oversample the brake trigger in order to work out exactly when the brake trigger actually occurred. If we know when this event occurred then we can work out how far the vehicle travelled before the next sample.

The brake trigger is sampled at a much higher frequency than the GPS signals, and this parameter is called the ‘Trigger Event Time’. During data processing this trigger event time is used to ensure the stopping distance is as accurate as possible.

On a VBOXIII the trigger event time is directly stored as a time.
On a VBOXII the trigger event time is not time but the counter number, which will be from 011520.

VBOX Tools and the Multifunction display automatically pick up the trigger event time and use this in any calculation of braking
distance. At the same time, the latency of the VBOX is taken into account to remove any additional distance caused by processing delays.

What are the effects of velocity noise on the measurements?

Velocity noise caused by poorly positioned antennas or by multipath reflections from nearby trees and buildings, can affect the measured time of an acceleration run or a deceleration run from a speed to zero.

For example, on an acceleration run, if the velocity channel is noisy, it is possible that a spike of velocity noise may go over the 100km/h threshold earlier than the vehicle actually went over 100km/h, hence producing a shorter time. It is good practice to run the VBOX in a lower dynamic mode for acceleration testing for this reason.

However, because distance is calculated by integration over time, this is effectively smoothing the data. This means that braking distances are much more tolerant of velocity noise. For a braking test, the VBOX should be in a high dynamic mode.

Why has my VBOX not detected the end of a brake stop?

1) Unsuitable environment or antenna placement causing noisy velocity data, so that the VBOX data never reaches 0.8km/h. See What does the VBOX use as zero velocity?
2) Onboard filtering has been used which may be smoothing the raw data so much that the exact point in time that the car reaches zero cannot be detected. See How does filtering affect results?
3) The vehicle being tested is tall and has soft suspension. This can cause the velocity before the Rock Back to not go below 0.5km/h.

If this is the case then look at the data in the graph screen to establish a minimum speed that the vehicle does reach before the rock back and apply this to the Report Generator test setup.

See also
What does the VBOX use as zero velocity?
How does filtering affect results?
What is Rock Back?

What does the VBOX use as zero velocity?

By default the VBOX starts logging when the speed goes above 0.5kmh. There is an option to change this to log all the time, but what difference can this make to the accuracy of the measurements?

In a brake stop, the distance travelled between 0.5kmh and 0.0kmh is negligible. In order to illustrate this, look at the following table where we analysed the data from a brake stop at 100kmh to 0.5kmh and from 100kmh to 2kmh to exaggerate the effect:

Run Num	Dist to 2km/h	Distance to 0.5km/h	Difference (M)
1	42.02	42.04	0.02
2	40.27	40.29	0.02
3	52.29	52.30	0.01
4	39.22	39.24	0.02
5	40.47	40.48	0.01
6	40.87	40.89	0.02

You can see that even changing the end point to as high as 2kmh only makes a 12cm difference. In fact, any braking distance measurement is taken down to 0.8km/h, as this eliminates the effect of Rock Back.

All acceleration runs use 0.5km/h as a starting point. On an acceleration, setting the start speed to 0.5kmh gives the system some tolerance to velocity noise when stationary, this stops the system triggering a false start. Again, this low threshold makes very little difference to the acceleration time from rest, usually less than 0.02s.

See also Rock Back

How is distance measured so accurately given GPS is only accurate to a few m?

GPS position has limitations in accuracy. If we were to use GPS position to measure distance, then we could only achieve distance accuracies of a few metres rather than centimetres. For this reason we use the velocity (derived from Doppler measurements) to measure distance instead. This eliminates the majority of the normal errors associated with GPS accuracy, and allows us to measure distance to within a few centimetres during a brake stop.

What is GPS latency and does it affect accuracy?

GPS latency is the time between the measurement of velocity, and when the VBOX reports this velocity.

This is only an important factor when using the VBOX velocity output compared with any external signals such as a brake trigger.

If you are using the VBOX with the supplied VBOX Tools software, or the multifunction display, then the latency is taken into account and does not affect the accuracy in any way.

If you are taking the CAN output of a VBOX or the raw data from a logged file, then you will need to be aware of the latency, and take this into account.

Latencies:
VBOXIII 12.5ms
VBOXIIS 55ms
VBOXIIDCF 35ms

What is Rock Back?

At the end of a brake stop, the car often rocks backwards as the suspension settles. This effect and the small amount of smoothing applied at source by all GPS engines causes what's known as 'Rock Back' velocity. The true point at which the vehicle stops is before this point.

With rock back, the stopping distance shown in the graph below is 25.23m. Without rock back, the stopping distance is 25.15m.

The VBOX uses 0.8 km/h as a threshold for measuring braking distance, and this eliminates 99% of these cases.

Note: In the plot to the left that the minimum speed before the rock back was 0.69 km/h, which is below the 0.8km/h threshold, so it
is eliminated.

See also
What does the VBOX use as zero velocity?

What causes poor position data?

The positional data channels lat, long and height are not only affected in the short term by local obstructions and reflections, but they are also affected by changes in the Ionosphere.

The slow changing nature of the Ionosphere causes the signals from the satellites to take slightly different times to arrive at the GPS antenna. As the time is critical to the triangulation calculation of 3D position, this causes a potential error degrading the accuracy of the absolute positional accuracy.

How do I test that the Base station has improved my position accuracy?

It is possible to test and demonstrate the positional accuracy benefits of a Base Stations with a simple static test.

Part 1:

• Setup the Base Stations in a suitable location, no trees or buildings within a minimum 100M radius
• Setup the VBOX in the same suitable location either using a car as a ground plane or using a survey grade style ground plane antenna.
• Use the following settings:
  • DGPS enabled (ensure the correct mode 40,20,2cm)
  • 1Hz logging
  • log continuously
• Ensure the VBOX is receiving and using the corrections, check a DGPS live window in VBOXTools.
• Leave the VBOX logging for a suitable period, for example 24 hours

Part 2:

• Setup the VBOX in the same location again with these settings:
  • DGPS disabled
  • 1Hz logging
  • log continuously
• Leave the VBOX logging for a suitable period, for example 24 hours

It is then possible to compare plots of the position of each sample in the two logged files. In the VBOXTools graph screen, the Map view should give a good indication of the accuracy of each system. More indepth
analysis can be performed using special software from Racelogic, designed to calculate the 95% CEP value of logged files. For details contact This e-mail address is being protected from spambots. You need JavaScript enabled to view it

How does filtering affect results?

Filtering can have a big effect at any point where velocity is changing at a high rate, i.e. at the beginning of an acceleration run, or when the brakes are pressed at the beginning of a brake run and then again when the car stops at the end of a brake run.

On Acceleration runs
Too much filtering will cause a delay in the logged data of the point at which the vehicle starts to move, which will cause the results to be too short. On an acceleration test between two nonzero speeds, then this has no effect.

On Brake Trigger stops
When the brakes are initially pressed and the vehicle starts to increase its level of deceleration, too much filtering will cause a delay in the velocity, which effectively holds a higher speed for longer before it shows the deceleration. This extra period of time at a higher velocity causes the resultant calculated distance to be too long.

On Brake Trigger and Brake stops
Too much filtering will cause a smoothing of the short period of time that a vehicle reaches zero before the 'Rock Back'. This can cause this point to be missed by the processing software and hence the distance and time calculated to the point after the 'Rock Back' will be too long.

See also

What is Rockback?

end faq

 

How does GPS work?

There are currently 24 US Military owned Satellites orbiting the earth on 20Km orbits, giving 100% world coverage. The free signals from these satellites can be used in different ways to determine a number of measured parameters of movement and position.

To measure the Longitude, Latitude and height, the GPS receivers measure the different delays in the signals coming from 4 or more satellites. The distance to each satellite is calculated and then using triangulation, the 3D position of the GPS antenna is calculated.

The GPS engines used in VBOX’s also calculate the Doppler shift in the carrier frequency of each satellite transmission to build an accurate measurement of the speed of the GPS antenna in the X, Y and Z planes. X is north/south, Y is east/west and Z is vertical velocity.

The X and Y velocities are combined to give ‘course over ground’ speed and heading data.

The velocity and heading channels are the accurate channels from which most VBOX data is derived: velocity, heading, accelerations, radius of turn, deviation, braking distance etc.

The less accurate positional channels, longitude, latitude and height are only used for plotting the vehicle path.

How does Differential GPS work?

A GPS engine is placed in a fixed position and left to work out its current position. By telling the GPS engine that it is not moving, it can monitor the signals coming from each satellite and work out the corrections which need to be applied to each satellite in order to remove the effects of delays in the signal travelling through the ionosphere.

These corrections are then broadcast to a moving GPS receiver.

There are two different types of DGPS correction with varying degrees of accuracy improvement available to VBOX’s.

What are the causes of noisy data?

The main causes of noisy data are objects that reflect or intermittently obstruct the signals from one or more of the satellites in view. Such obstacles are usually trees or buildings. Do not place another GPS antenna close to the VBOX antenna, as GPS antennas radiate a small amount of noise at exactly the wrong frequency!

The measurement of the time taken for the satellite signal to reach the antenna is the important factor, so anything that may cause the signal to take a longer path (such as reflection) is undesirable. When the signal reaching the antenna is made up of the signals coming from the direct path plus a reflected path, it is known as Multipath, and it is detrimental to the accuracy of the measurements.

If an antenna is not mounted on a large enough ‘ground plane’ then the multipath reflections will also be from the ground beneath the antenna. If you are using the antenna on something without a large ground plane (such as a bike or carrying the unit by hand), then you can put a sheet of metal underneath the antenna (can be silver/copper foil), or use an antenna with strong multipath rejection properties (available from Racelogic). These kinds of antennas are much larger and more expensive than the standard antenna supplied with the VBOX.

What causes poor position data?

The positional data channels lat, long and height are not only affected in the short term by local obstructions and reflections, but they are also affected by changes in the Ionosphere.

The slow changing nature of the Ionosphere causes the signals from the satellites to take slightly different times to arrive at the GPS antenna. As the time is critical to the triangulation calculation of 3D position, this causes a potential error degrading the accuracy of the absolute positional accuracy.

Does the weather affect the GPS signals?

No, in general the weather has no effect on the GPS signals and logged data. However, any build up of snow on the antenna should be
avoided, as large amounts of water will absorb GPS signals.

Is there a way to know velocity quality?

Yes on a VBOXIII, there is a channel called velocity quality. The Velocity quality channel is a value that relates to a Spherical Error Probable (SEP) with units in Kph. As it is a Spherical Error Probable i.e. 3D, it also includes the vertical velocity signal quality.

So if the value of the Velocity quality is 0.1Kph then the value of Velocity measured at that point will be within 0.1Kph of the true value.

Where should I place my GPS antenna?

GPS antennas where possible should be placed on a large ground plane such as a car roof.

If an antenna is not mounted on a large enough ‘ground plane’ then the multipath reflections will also be from the ground beneath the antenna. If you are using the antenna on something without a large ground plane (such as a bike or carrying the unit by hand), then you can put a sheet of metal underneath the antenna (can be silver/copper foil), or use an antenna with strong multipath rejection properties (available from Racelogic). These kinds of antennas are much larger and more expensive than the standard antenna supplied with the VBOX, but they can be mounted on a pole to get them as high as possible.

The GPS antenna should also be placed as far away as possible from any other potential obstructions, such as roof bars or other GPS or Radio antennas. This will reduce the probability of multipath effects.

On a motorbike the antenna should be placed as far from the rider as possible to reduce the satellite signal shadowing effect of therider. Usually the best place is at the back of the bike, or on the rider’s head. For best results use one of our special GPS antennas which can be mounted on a pole.

Why do I have no satellite reception?

Common problems with GPS antennas are damage to the cable and the connector.

The cable should be placed in a position that avoids tight angles being inflicted on the cable, as this can damage the thin core. The VBOX should also be securely positioned to avoid the cable/connector join being strained in violent vehicle manoeuvres.

Dirt in the connector is also a problem; the GPS signal is low power so any further attenuation will cause problems.

end faq

Over what distance will the telemetry work?

The operational range of the telemetry modules depends largely on the conditions in which they are used. For best results, the antennas must be in plain sight of each other and one (or ideally both) of them raised far above the ground. At ground level they also work better when they are mounted on a ground plane, such as a car roof.

Expected maximum range:

• Difficult environment (blocked by buildings or trees) – 150 to 300 metres (500 to 1,000 feet).
• Open environment with antennas at ground level (clear view with antennas on car roofs) – 1,000 to 1,400 metres (3,400 to 5,000 feet).
• Open environment with antennas at height (clear view with antennas mounted on masts of building rooftops) – up to 3,500 metres (11,000 feet). This range has been measured at larger distances 10,000M when the antennas where on hill tops with line of sight.

What is the maximum VBOX serial Data Rate with Telemetry?

The telemetry modules can only transmit data at a limited baud rate, which restricts the amount of serial data that can be transmitted via RF. In order to allow the data to be transmitted without errors, the serial stream must be limited to 5Hz using the VBOXTools software.

A 5Hz serial rate will allow accurate transmission of the standard GPS channels, plus 24 CAN channels. Even at 5Hz, the information sent to VBOXTools is very useful, for example it will give VBOXIII brake test results accurate to about 10cm. Racelogic recommends that customers use serial data to provide an instant assessment of whether or not tests are valid, with full analysis conducted on data logged to compact flash card once a number of valid tests have been completed.

end faq

What is CAN?

CAN stands for Control Area Network. It is a form of multiplexed wiring designed by Bosch and allows the linking of a number of control systems together, normally in a vehicle, so that they can share information.

In the past it would have been necessary to have at least one wire for every signal on a vehicle making wiring looms bulky and expensive. CAN bus multiplexing allows a large number of signals to be transferred digitally using only a pair of twisted wires.

Sharing of information also reduces the number of sensors that are needed. For example, the engine controller has its own sensor to monitor coolant temperature. Using CAN it can periodically broadcast the temperature reading so that the information is available to any other systems on the car that are interested. One such system might be the instrument cluster, which would use the information to drive its temperature gauge.

How do VBOX's use CAN?

The robust nature of CAN Bus has meant that it has become widely used in industry for carrying measurement data in harsh environments. Because of this, Racelogic adopted CAN Bus as a method for transferring data between the VBOX data loggers and external modules such as the ADC03 and TC8.

The VBOX uses CAN in two ways:

1) The first is simply to transmit GPS data for use with the Multifunction display or other third party loggers. The format of the GPS data within the messages is fixed and documented in the various VBOX user guides.

2) The second way that VBOX uses CAN Bus is, as previously mentioned, to communicate with external Racelogic modules. When a VBOX is first powered up, it scans the CAN Bus, looking for any Racelogic modules. If a module is found, the VBOX will send out a CAN message to request data from it in synchronisation with incoming GPS data. The module will reply to the VBOX request with its measured input value (temperature, yawrate, voltage, etc). The CAN identifiers used by the VBOX to communicate with the external modules are based on the type of module and the module serial number. This allows the VBOX to individually access each module on the CAN Bus.

The standard bus rate for CAN on a VBOX network is 500K although it can be changed to other values. Typical Baud rates used for CAN Bus communication range from 125Kbit, 250Kbit, 500Kbit up to a maximum of 1Mbit.

I am having trouble logging vehicle CAN data

Typical causes of error in CAN Bus systems include the following:

• Incorrect Channel settings for the incoming CAN signal, i.e. CAN format, CAN id, Byte position Byte length.

• Wrong Baud Rate between connected modules and logging system. No data will be transferred at all.

• CAN High and CAN Low connected the wrong way round. No data will be transferred at all.

• Lack of termination resistor. This will cause intermittent bursts of, or, no data to be transferred.

• The CAN port assignment is set the wrong way round - There are two CAN ports on a VBOXIII.

Where can I find the CAN bus on a vehicle?

The use of CAN Bus in road vehicles to date has been mostly for interECU communication and therefore it is common for vehicles not to have CAN available on a convenient connector. In cases such as this, it may be necessary to tap directly into vehicle CAN wiring to pick up signals. Typical places to pick up CAN include the ABS system (look for a pair of twisted wires, but ignore the four wheelspeed wires) or on the back of the dashboard (look for a pair of twisted wires).

If the vehicle does have CAN Bus on the OBD connector, it will normally be on Pins 6 and 14 as indicated below. See our Vehicle CAN database to find out which signals are available.

 

 

How do I know if termination resistors are required?

A CAN Bus network must have a termination resistor between CAN High and CAN Low for it to work correctly. For maximum range over long distances, the ideal termination is one 120 Ohm resistor at each end of the bus but this is not critical at short (

Each VBOX has a resistor built in to terminate the CAN Bus shared with other Racelogic modules. If however, Racelogic modules are used without a VBOX in a 'standalone' mode, it is important to check that the CAN Bus has a termination resistor fitted. If in doubt, measure the resistance between CAN High and CAN Low without the system poweredup. The resistance should ideally be less than 120 ohms and closer to 60 ohms if a resistor is fitted at each end of the bus.

end faq

 

When should I use filtering?

Increasing the level of filtering applied to data effectively reduces the bandwidth of the VBOX response and smooths the velocity and acceleration measurements.

During the measurement of data in high dynamic tests, the level of applied filtering should be kept to a minimum to capture fast transients, e. g. braking tests, lane change tests and steering response tests.

However some tests that are of a lower dynamic nature can be made using higher levels of filtering to give smoother data, e. g. acceleration tests, circuit laps and coastdown tests.

How does filtering affect results?

Filtering can have a big effect at any point where velocity is changing at a high rate, i.e. at the beginning of an acceleration run, or when the brakes are pressed at the beginning of a brake run and then again when the car stops at the end of a brake run.

On Acceleration runs
Too much filtering will cause a delay in the logged data of the point at which the vehicle starts to move, which will cause the results to be too short. On an acceleration test between two nonzero speeds, then this has no effect.

On Brake Trigger stops
When the brakes are initially pressed and the vehicle starts to increase its level of deceleration, too much filtering will cause a delay in the velocity, which effectively holds a higher speed for longer before it shows the deceleration. This extra period of time at a higher velocity causes the resultant calculated distance to be too long.

On Brake Trigger and Brake stops
Too much filtering will cause a smoothing of the short period of time that a vehicle reaches zero before the 'Rock Back'. This can cause this point to be missed by the processing software and hence the distance and time calculated to the point after the 'Rock Back' will be too long.

See also
What is Rockback?

What are the different types of filter, and when should I use them?

On all VBOX’s except VBOXLite, the amount of smoothing that can be applied at source by the GPS engine to the velocity channel can be adjusted.

There are three preset levels of smoothing labelled as dynamic levels:

High, This is the lowest level of smoothing and should be used for any Brake stops or high dynamic vehicle tests.
Normal, This is an intermediate level of smoothing that will give a smoother velocity, for tests such as acceleration runs between two nonzero speeds.
Low, This is the highest level of smoothing available and can be used where live velocity is required and needs to be as smooth as possible or for coastdown tests.

VBOX level filtering is a real time filter, so once the data has been generated, the effect of the smoothing cannot be reversed. You can always use post processing smoothing, which can be adjusted whilst reusing
the same piece of original data. Further smoothing can be applied in the VBOX in real time using a Kalman Filter, where available.

See also
What is a Kalman Filter?

What is a Kalman Filter?

A Kalman Filter is a very effective type of filter that, in the case of VBOX’s, compares the positional and the velocity data as part of the smoothing routine. I.e. if the velocity exhibits a jump in speed over a short time yet the positional data does not corroborate this jump in speed, then the jump will be reduced and smoothed accordingly. This applies in the same manner for a jump in position that is not backed up by a jump in speed.

Live Kalman Filtering
Kalman Filtering that is applied live by a VBOX (where available), like any live filtering process, will not only smooth the data but will delay transients and sudden velocity changes in the data. This should therefore be used with caution, and only in cases where a live smoothed velocity or position is required from the VBOX.

Post processing Kalman Filtering
A Kalman filter that is applied to logged data has the benefit of being able to smooth individual data samples with respect to the values before and after the smoothed point. This has the major benefit of having virtually no effect on the latency of transients and velocity changes. This type of smoothing is available under ‘Tools’ in the VBOX Tools software.

Where possible, it is advised to log the raw data with as little smoothing as possible, and then apply postprocessing smoothing as required. If smoothing is applied at source, detail can not then be recovered.

What smoothing is used in VBOXTools software?

The smoothing that can be applied to individual channels in the Graph screen and in Report Generator is a ‘window smoothing’ routine. It smoothes an individual data sample using data from before and after the sample.

The number of samples used in the smoothing and the level of smoothing applied is determined by the chosen smoothing level. The software coded expression for this is as follows.
Tempsmooth =0
For loop2 = -smoothlevel to smoothlevel do
temp = loop + loop2
tempsmooth = tempsmooth + rawdata( temp)
new smoothed value (loop) = tempsmooth / (2 x smoothlevel +1)
smoothlevel = the smoothing level you wish to apply.

This smoothing is only for visual reference, the raw data is not changed using this process.

end faq

How do VBOX Input Modules and VBOX's communicate?

The communication and connection between VBOX's and VBOX Input Modules is via a Racelogic proprietary CAN bus. A CAN bus connection means that many different VBOX input modules can be 'daisy chained' together along the same CAN bus connection.

The VBOX controls the flow of data from the modules by polling the input modules with a data request signal, in the form of a zero data CAN id.

The CAN id's for each channel of an input module are dependent on the serial number of the module. This CAN bus connection has a data rate of 500 Kbaud and uses the Motorola CAN protocol.

Each channel from any VBOX input module is 4bytes 32 bits. When connected to VBOXIII's or VBOX20SX's input modules will transmit each 32bit channel as an IEEE 32bit float.

On all VBOXII's and VBOXLite's each 32bit channel is transmitted as a Racelogic Float, which a Racelogic version of IEEE 32bit floats.

See also

What is CAN?

Calculating CAN id's of VBOX input modules.

What is an IEEE 32bit float?

Can I use an input module without connecting it to a VBOX?

Yes, all input modules are capable of operating in a configurable standalone mode. In this mode they output data on a configurable timed or polled CAN bus.

Calculating CAN id's of VBOX input modules.

If it is required to log the VBOX data and input module data on an external CAN bus data logger, then it is possible to connect the Racelogic CAN bus to the external data logger, providing that the CAN bus from the external data logger does not also contain much additional CAN bus data.

If it is required to log VBOX CAN traffic between input modules and VBOX's then you will need to know how to understand the CAN id's of input modules when used in this way.

The CAN id is made by multiplying the serial number by 2048, e. g. the FIM02 Module serial number 005430 would give the CAN id as 5430 * 2048 = 11120640 (a9b000hex).

The hex format of the CAN id is the commonly used format. This first id would contain channels 1 and 2. Then increment the hex address by 2 (i.e. a9b002) to get channels 3 and 4.

If there are more channels in the Module then add another 2 to the hex address for the id of the next two channels.

Another example ADC03, serial number 004182: 4182 * 2048 = 8564736 which equates to 82b000 in hex

Channel 1,2 have the CAN id 82b000

Channel 3,4 have the CAN id 82b002

Channel 5,6 have the CAN id 82b004

Channel 7,8 have the CAN id 82b006

Note: Input modules when used in stand-alone mode do not use CAN id's calculated this way.

Why is my module not recognised by the VBOX?

If an input module is unrecognised in VBOXsetup by the VBOX:

• Check that the cable is connected in to the correct socket on the VBOX and on the input module.
• Check that the input module is not in a standalone mode and that it is set to CAN mode 0 (Racelogic mode).
• On VBOXIII's also check that the Racelogic CAN port is associated with the socket to which you are connecting your modules.

Which module is compatible with my VBOX?

To find out which module, display, etc. is compatible with your VBOX, please have a look at the VBOX Compatibility Matrix here.

end faq

Why are there three USB modes?

With USB communications each USB device is individually signed. This means that each time a new device is connected to your computer via USB it will require your computer to reload drivers.

VBOX products use USB in three different ways that each requires drivers to be recognised individually. These modes are:

Mode 1: Using the USB to read and write data on the memory card in a VBOX

Mode 2: Using the USB to upgrade a VBOX

Mode 3: Receiving live VBOX data over USB.

Mode 1 is automatically detected by Windows, so it does not need a specific driver. The drivers for Mode 2 and Mode 3 are loaded during the VBOXTools software CD installation process.

However, when you try to stream data to VBOXTools software, enter VBOX Setup or perform an upgrade, you will need to go through the 'Found New Hardware Wizard' to let Windows install the driver automatically. You will have to do this once for each unit, and may need to repeat the process when using different USB ports. You will also need to do this separately for each of Mode 2 and Mode 3, as they require different drivers.

How do I install the USB drivers?

If the Racelogic Comms drivers are not installed Windows will display an 'Event message' popup when a Racelogic USB device is connected.

If you are installing the driver package on its own (Download available from the Racelogic website) you will need to follow the installer to complete the installation.

Note: Some of the software installation CDs will install the Racelogic Comms drivers automatically.

Click the Install button to continue, if you have restricted permissions on your user account you may need to ask a member on the computer with administrator privileges to confirm the installation.

If you are a Windows Vista or 7 user the UAC will pop up with a warning after this point. To stop these messages from popping up again please tick the 'Always trust software from "Racelogic Ltd"' box.

After the installation has complete you can then connected your Racelogic product.

Note: Some systems will require a restart after the installation, if so a popup box will prompt you.

Why won't my VBOX Mini communicate via USB?

On the USB enabled VBOX's ensure that the correct USB mode has been set on the VBOX, i.e VBOXTools mode or card reader mode. If the VBOXTools fails to recognise the live connection to the VBOX, retick the USB com port in the VBOXTools options.

How is the Serial Port used on a VBOX?

The serial port on all VBOX's provides a serial data output of sats, time, lat, long, velocity, heading, height, vertical velocity and trigger event time. This is used by VBOX Tools software and the LED display. The standard baud rate is 115200 baud.

On all VBOX's there is also an RS232 serial port on two spare pins of the CAN socket. This serial port is a dedicated port used for Basestation DGPS correction information, which is received via telemetry.

On VBOXIII's and VBOX2SX units the primary serial port also contains a CAN bus connection on two spare pins.

Why is the number of serial channels limited?

At a serial data rate of 115200 there is a limitation in the number of channels that can be transmitted. This is limited further by higher VBOX log rates like 50 and 100Hz.

At 20Hz (or less) it is possible to transmit all the VBOX standard channels plus 32 CAN channels.

At 50Hz it is only possible to transmit the standard VBOX channels.

At 100Hz it is only possible to transmit the channels Sats, Time, Velocity, brake trigger event time.

On a VBOXIII the channels are automatically limited on the serial data stream according to the selected log rate.

When using the VBOX serial outputs with a Racelogic Telemetry system, the telemetry link has a Radio data rate of 9600baud. As such a VBOX must have the serial set to 5Hz when used with the telemetry link.

What is the VBOX serial protocol on the VBOXII?

115200 Baud, no parity, 8 data bits, 1 stop bit

Message format : $VBOXII,nnnn0000,stttaaaaoooovvhheeezzmmmggcc

The $VBOXII and commas are in ASCII, the rest is in binary.

The first four bytes of the reserved nnnn0000 bytes indicate the presence of the channels in the serial data stream. For example if only Sats and Velocity are present the corresponding bit masks 0x00000001 and 0x00000010 would equate to the nnnn0000 bytes equalling 0x0000001100000000.

Racelogic CAN modules

When CAN channels are also selected to be present in the Serial data stream, the data stream will look like the following:

$VBOXII,nnnn0000,stttaaaaoooovvhheeezzmmmggcc $NEWCAN,XXXX,YYYY.....YYYYZZ

$NEWCAN,XXXX,YYYY.....YYYYZZ this is the additional CAN channel information to the serial data stream.

The ZZ is a two byte checksum. - This is the same format as before see NOTE 1 below.

The format for the serial string is $NEWCAN,XXXX,YYYY.....YYYYZZ.

Where XXXX is a 32-bit value.

The length of YYYY depends upon the value of XXXX. For each bit set in XXXX the length of YYYY is incremented by four, i.e. if XXXX = $0001 then YYYY will be four bytes long. The order in which the data will come across depends upon the order in which you select the channels from the set-up screen. For example if the first channel you choose to log is FIM Channel 1 then the first 4 bytes will contain the data from the FIM. If the second channel was ADC02 Channel4 then the next 4 bytes will contain data for the ADC02. If you then remove (choose not to log) FIM Channel 1 and select ADC02 Channel 1 then the first 4 bytes will now contain the data for ADC02 Channel 1.

The data transmitted for each channel (YYYY) is in a Racelogic format.

If you take each YYYY you can split it into four bytes the first byte is a signed exponent the next three are a signed mantissa, e.g. if YYYY = 0x03 0x12 0x11 0x00 this equates to exponent = 0x03

mantissa = 0x121100 or 1184000 decimal

Therefore the value is 1.184000E03

*Note 1

CRC Calculation example :

s[n] is a string containing the message

Polynomial:= 4129

CRC:=0;

for Loop:=1 to Length(s) do

begin

Temp:=s[Loop];

CRC:= CRC xor (integer(Temp) * 256);

CRC:= CRC mod 65536;

for i:=7 downto 0 do

begin

if ( (CRC and 32768)=32768) then

begin

CRC:= CRC *2 ;

CRC:= CRC xor Polynomial;

end

else

begin

CRC:= CRC *2 ;

end;

CRC:=CRC mod 65536;

end;

end;

result:=CRC;

What is the VBOX serial protocol on the VBOXIII?

115200 Baud, no parity, 8 data bits, 1 stop bit

Message format : $VBOX3$,nnnn0000,stttaaaaoooovvhheeezzxxyy1111222233334444mmmggggcc

The $VBOX3$ and commas are in ASCII, the rest is in binary.

The first four bytes of the reserved nnnn0000 bytes indicate the presence of the channels in the serial data stream. For example if only Sats and Velocity are present the corresponding bit masks 0x00000001 and 0x00000010 would equate to the nnnn0000 bytes equaling 0x0000001100000000. If Sats, Time, Lat, Long, Velocity, Heading , Height, Vertical Velocity, GPS Latacc and Longacc are present then the mask bytes would be: 0x000003FF00000000.

Although not all of the channels listed below are present in the serial stream unless selected in VBOX setup software, the table shows the order in which they appear in the data stream.

Racelogic CAN modules

When CAN channels are also selected to be present in the Serial data stream the data stream will look like the following:

$VBOX3$,nnnn0000,stttaaaaoooovvhheeezzmmmggggcc $NEWCAN,XXXX,YYYY.....YYYYZZ

$NEWCAN,XXXX,YYYY.....YYYYZZ this is the additional CAN channel information to the serial data stream.

The ZZ is a two byte checksum. - This is the same format as before see NOTE 1 below.

The format for the serial string is $NEWCAN,XXXX,YYYY.....YYYYZZ.

Where XXXX is a 32-bit value, representing the number of preceding bytes.

The length of YYYY depends upon the value of XXXX. For each bit set in XXXX the length of YYYY is incremented by four. i.e. if XXXX = $0001 then YYYY will be four bytes long. The order in which the data will come across depends upon the order in which you select the channels from the set-up screen. For example if the first channel you choose to log is FIM Channel 1 then the first 4 bytes will contain the data from the FIM. If the second channel was ADC02 Channel4 then the next 4 bytes will contain data for the ADC02. If you then remove (choose not to log) FIM Channel 1 and select ADC02 Channel 1 then the first 4 bytes will now contain the data for ADC02 Channel 1.

The data transmitted for each channel (YYYY) is in a standard IEEE 32 bit Float format.

IEEE 32 bit Float numbers

The bit pattern b₁b₂b₃...b₉b₁₀b₁₁...b₃₂ of a word in a 32-bit machine represents the real number

(-1)^s x 2^e-127 x (1.f)₂

where s = b₁, e = (b₂...b₉)₂, and f = b₁₀b₁₁...b₃₂.

Note that only the fraction from the normalized mantissa is stored and so there is a hidden bit and the mantissa is actually
represented by 24 binary digits.
Example of the Fraction part of the calculation the 23 bits 01110111100110110011110 would be come 1. 01110111100110110011110
The 23 bits after the 1. represent the presence of the binary weighted fractions ,½, ¼, 1/8, 1/16, 1/32,1/64
etc.
*Note 1
CRC Calculation example :
s[n] is a string containing the message
Polynomial:= 4129
CRC:=0;
for Loop:=1 to Length(s) do
begin
Temp:=s[Loop];
CRC:= CRC xor (integer(Temp) * 256);
CRC:= CRC mod 65536;
for i:=7 downto 0 do
begin
if ( (CRC and 32768)=32768) then
begin
CRC:= CRC *2 ;
CRC:= CRC xor Polynomial;
end
else
begin

CRC:= CRC *2 ;end;
CRC:=CRC mod 65536;
end;
end;
result:=CRC;

What is a Racelogic 32-bit Float?

Racelogic 32bit float numbers are used in the CAN communications between input modules and VBOXIIDCF/VBOXLite units.

This format is also used for the representation of channel data from input modules in the VBOXIIDCF/VBOXLite serial data stream.

A 32bit number YYYY can be split it into four bytes the first byte is a signed exponent the next three are a signed mantissa.

e.g. if YYYY = 0x03 0x12 0x11 0x00 this equates to exponent = 0x03

mantissa = 0x121100 or 1184000 decimal

Therefore the value is 1.184000E03

What is an IEEE 32-bit float?

IEEE 32bit float numbers are used in the CAN communications between input modules and VBOXIII/VBOX2SX units. This format is also used for the representation of channel data from input modules in the VBOXIII/VBOX2SX serial data stream.

A floating point number can be represented in the following form:
v = s × 2e × m

Where
v is the number
s is the sign
m is the mantissa
and
s = +1 (positive numbers) when the sign bit is 0
s = −1 (negative numbers) when the sign bit is 1
e = Exponent − 127 (in other words the exponent is stored with 127 added to it, also called "biased with 127")
m = 1.Fraction in binary (1 ≤ m < 2)

For example, 0.15625 can be represented by a 32bit number in the following way:
s = +1
e = 3
(from 124 – 127)
m = 0.25
In this example, v = +1 x 2 3
x 1.25 = +1 x 0.125 x 1.25 = 0.15625

end faq

Why do I need to upgrade my VBOXTools software?

It is strongly advised that you upgrade your VBOXTools to the latest available version to benefit from the latest bug fixes and new features. We can provide better support if the latest software versions are being used.

How do I upgrade my VBOXTools software?

Download the latest VBOXTools software from the VBOX Support/Downloads & Updates section of the website. This will require a valid username and password, if you do not have one then please contact your local VBOX distributor or Racelogic for assistance.

Extract the Setup.exe file from the downloaded zip file to your desktop.

If you have already installed VBOX Tools on your computer, go to the Start-Programs-VBOX link on your computer and choose the option Uninstall VBOXTools.

Click on Setup.exe file to start the installation of the new software version. The uninstall and installation process will not delete or remove any of your log files or XXXXX

How do I upgrade a VBOXIII or VBOXIII speed sensor?

Download the latest firmware .zip file from the VBOX Support/Downloads & Updates section of the website. Within the .zip file you will find a text file and two or more .UPG upgrade files. Open the text file in Notepad, then follow the instructions, guiding you on which upgrade files to use.

VBOXIII’s and VBOXIII speed sensors are upgraded by copying the relevant upgrade file to a CF card and inserting this into a VBOX which is powered, or boot a VBOX up with the CF card inserted.

After inserting a CF card with an upgrade file, all of the LED’s will illuminate, followed by flashing of the green and blue LED’s, then the VBOX will re-initialise and begin normal operation. This will be indicated by the green SAT LED flashing slowly as the VBOX searches for satellites.

Why has my VBOXIII not taken the upgrade file?

During the upgrade process an upgrade log file will have been created on the CF card. If you run into problems, you can access this file and examine the contents for any clues as to why the upgrade failed (the most common reason is a lack of valid support contract for the particular VBOX).

How do I upgrade a VBOXII or VBOXLite?

Unlike a VBOXIII, to upgrade a VBOXII or VBOXLite you need to use some dedicated PC software.

Download the latest ‘.ruf’ firmware file from the VBOX Support/Downloads & Updates section of the website, ensuring it is the correct file for the VBOX model you are upgrading.

Also ensure that you have the latest VBOX Upgrader Software, also available on the website under ‘Utility Updates’.

This software is automatically installed during a VBOXTools software installation into the following folder \Program Files\Racelogic\Utilities\Upgrader.

Connect your PC to the VBOX via the VBOX serial lead and apply power to the VBOX.

Either double click on the ‘.ruf’ upgrade file, or run the VBOX Upgrader software and load in the ‘.ruf’ file.

Then follow the onscreen instructions and the VBOX firmware will be upgraded. At the end of the process power down the VBOX when prompted, before further use.

During the upgrade process an upgrade log file will have been created. If you run into problems, you can access this file and examine the contents for any clues on why the upgrade failed.

How do I upgrade USB enabled VBOX's?

Download the latest ‘.ruf’ firmware file from the VBOX Support/Downloads & Updates on the website ensuring it is the correct file for the VBOX model you are upgrading.

Also ensure that you have the latest VBOX Upgrader Software, also available on the website. This software is automatically installed during a VBOXTools software installation into the following folder \Program
Files\Racelogic\Utilities\Upgrader.

If you are connecting your VBOX device to your computer with the USB cable for the first time then follow the instructions in the Section ‘Using the USB cable‘ before following the instructions below.

• If you are upgrading a VBOXmini then press and hold the ‘MODE’ button whilst power is connected.
• Other wise press and hold the ‘◄’ button whilst the power is connected to the VBOX.
• The screen will now display the UPGRADER screen, showing that it is ready for upgrading.
• Connect the USB cable to your computer.
• Double click on the ‘.ruf’ firmware upgrade file that you have downloaded from the website.
• At the end of the process disconnect the USB cable and then disconnect and then reconnect the power.

How do I upgrade the Multi-function display?

Download the latest ‘.ruf’ firmware file from the VBOX Support/Downloads & Updates on the website.

Also ensure that you have the latest VBOX Upgrader Software, also available on the website. This software is automatically installed during a VBOXTools software installation into the following folder \Program
Files\Racelogic\Utilities\Upgrader.

Connect the serial cable, RLVBCAB01, from the PC direct to the ‘serial’ socket on the MFD. The MFD must also be connected to the VBOX via the CAN lead to provide power during this process. Before firmware can be updated the ‘REPROG STATUS’ of the display must be enabled. The ‘REPROG STATUS’ option is found with in the ‘CONFIG Display’ menu of the MFD. In this option press ’OK’ then ‘◄’ then ‘OK’ again to enable it.

Either double click on the ‘.ruf’ upgrade file, or run the VBOX Upgrader software and load in the ‘.ruf’ file.

Follow the onscreen instructions and the MFD firmware will be upgraded. At the end of the process power down the MFD when
prompted, before further use.

During the upgrade process an upgrade log file will have been created.

How do I upgrade VBOX modules?

Download the latest ‘.ruf’ firmware file from the VBOX Support/Downloads & Updates on the website.

Also ensure that you have the latest VBOX Upgrader Software, also available on the website.

This software is automatically installed during a VBOXTools software installation into the following folder \Program Files\Racelogic\Utilities\Upgrader.

Connect the serial cable, RLVBCAB01, from the PC direct to the serial socket of the module. The module must also be connected to the VBOX via the CAN lead to provide power during flash upgrade process.

Either double click on the ‘.ruf’ upgrade file, or run the VBOX Upgrader software and load in the ‘.ruf’ file.

Then follow the onscreen instructions and the module firmware will be upgraded. At the end of the process power down the module when prompted, before further use.

During the upgrade process an upgrade log file will have been created.

How do I upgrade a single socket IMU/YAW02 module?

The upgrade process is the same as for the VBOX modules, except that the splitter cable RLVBCAB30 is required to allow serial and
power connections to the IMU (or YAW02) at the same time. +12v will need to be applied to the flying lead of the CAB30 cable.

What should I do if the upgrade fails?

Check all cable connections and the connection of a reliable power supply, and then try again. In all upgrades a text log file is created, this file can be emailed to your local VBOX agent to help diagnose any upgrade problems.

In some cases the upgrade process may fail towards the end, during the EEPROM programming stage. This can be overlooked, as the important stage is the programming of the Flash and this was probably successful. If the upgrade failed during the EEPROM stage then it will only mean that your basic settings like velocity units will need to be manually reset.

end faq

Can I log additional non-GPS data with a VBOX?

Yes, this is possible with the Racelogic range of input modules that connect to a VBOX via a proprietary CAN bus connection.

The input modules allow voltage; frequency/pulse, thermocouple and vehicle CAN bus signals to be logged along with the VBOX GPS data.

See the Peripherals / Modules / Input Modules  for further information.

What is the format of a 'vbo' file?

Data on a VBOXIIDCF is logged in a text format. Below is an example of the format with data explanations.

File created on 31/07/2006 at 09:55:20 'generated from the VBOX internal Real time clock'

[header] 'list of the titles of each logged channel'

satellites
time
latitude
longitude
velocity kmh
heading
height
vertical velocity kmh
trigger event time in clock counts

[channel units] 'lists the units of any input module channels'

[comments]

(c) 2001 2003 Racelogiv
VBox II Version 4.5a 'VBOX firmware version'
GPS : SSX2g 'GPS type and firmware version'
Serial Number : 005201
CF Version 2.1d
Log Rate (Hz) : 02.00
Software Version : 1.4.5 (Build 005) 'software version, only present on files that have been re-saved through VBOXTools'
Security Code : %//+$%00"0/0+

[column names]

sats time lat long velocity heading height vertvel event1

[data] 'VBOX data in space delimited column format'

137 162235.40 +03119.09973 +00058.49277 000.140 321.85 +00152.58 +000.000 00000
137 162235.90 +03119.09973 +00058.49277 000.220 065.93 +00152.58 +000.000 00000
137 162236.40 +03119.09973 +00058.49277 000.250 356.43 +00152.59 000.072 00000

Explanation of each channel's format in the logged file.

Sats: This is the number of satellites in use in decimal format. 64 is added to this number if the brake trigger input is activated. 128 is added to this number if the VBOX is using a DGPS correction
e.g. in the file above the sats column shows 137 = 128(DGPS) + 9 sats

Time: This is UTC time since midnight in the form HH:MM:SS.SS,

Latitude: Latitude in minutes MMMMM.MMMMM +ve = North e.g. 03119.09973M = 51D, 59M, 5.9838S

Longitude: Longitude in minutes MMMMM.MMM +ve = West e.g. 00058.49277M = 00D, 58M, 29.562S

Velocity: Velocity in km/h

Heading: Heading in degrees with respect to North.

Height: Height above sea level in meters based on the WGS84 model of the earth used by VBOX GPS engines.

Vert-velocity: Vertical velocity in km/h +ve velocity uphill –ve velocity downhill.

Trigger event time: This is the trigger event time measured in counts up to 11520.

Input Channels: Any channels from input modules are logged in an exponential form, e.g. +1.23456E+02 = 123.456

What is the logged file format (VBOXIII)?

The logged file format of the VBOXIII is essentially the same as the VBOXII apart from the comments section, which contains a record of the VBOXIII Kalman Filter settings.

[comments]

(c)2001 2005
Racelogic
VBox3 V02.04 Build 0006
GPS Firmware : 2.4Z February 14 2005
Serial Number : 00030413
Log Rate (Hz) : 100.00
Kalman Filter Pos
: 2 Vel : 2
GPS Time
Software Version : 1.3.1 (Build 017)
Security Code : &,&$%.%"
0/+&

How can I organise and name files on a compact flash card?

If you have a VBOXIII then with the use of a VBOX manager, named folders can be created on the Compact Flash card. Any of the named folders can then be chosen by the VBOX manger as the logged file location, then the files logged are given the name of the folder, e.g. if the folder was called accel then the files would be accel1.vbo, accel2.vbo etc.

See also VBOX Manager

How long can I log to a compact flash card?

Each digit and space in the logged message is an ASCII character and as such takes up one byte. As an example, the message below contains the standard VBOX channels plus five CAN channels, this then contains 71 bytes of standard VBOX data and 50 bytes of CAN channel data. In this example this adds up to 121 bytes per sample (one line of data)

[column names]

sats time lat long velocity heading height vertvel FL_wspd FR_wspd RL_wspd RR_wspd

[data]

007 161950.50 +03119.01379 +00063.07847 111.75 185.25 +00165.49 +001.224 +1.11750E+02 +1.11750E+02 +1.11250E+02 +1.10750E+02

The number of bytes stored per second is then dependant on the log rate of the VBOX.

For 100Hz log rate the number of bytes stored per second will be 100 X 121 bytes = 12100 bytes = 12.1Kbytes.

So to calculate maximum log time on a compact flash card, divide the compact flash card size by the number bytes logged per second.

For a 128Mbyte card this would be 128000000/12100 = 10578 Seconds.

Divide this by 3600 to get this time in Hours. 10578/3600 = 2.9 Hrs continuous logging.

How long can I log to an SD card in a VBOX Mini?

A VBOX Mini without an input module connected logs are 35bytes/sample. At the log rate of 10Hz there are 350bytes/second. Hence the number of bytes/hour = 1260000 bytes/hour.

Therefore a 64Mb card will offer 50 hours of continuous logging.

How can I control the logging?

There are two logging modes available on most VBOX's:

Log all the time: With this mode enabled data is constantly logged to the memory card regardless of velocity. (Not available on VBOXMini).

Log only when moving: In this mode logging only occurs when the measured velocity is over 0.5km/h.

In the VBOXIII an Advanced logging option also allows the logging to start and stop at configurable threshold values of any logged channel. See VBOXTools manual for further information.

When should CF and MMC/SD cards be formatted?

Data and files on memory cards should simply be copied, moved or deleted, and it should not be necessary to format cards. The manufacturers of memory cards optimise cards for the fastest read/write speed, so that they work well with digital cameras. The same is applicable to VBOX's.

However Windows based format routines are designed to optimise memory cards for the most efficient use of memory space and not access speed. If you do need to format the CF or SD card please check the format type, this should be stated in the VBOX manual.

What can cause logged data to become corrupt?

If the card is removed whilst the VBOX is logging and data is being written to the card then it is highly likely that the file will be corrupt because the last line of data will be half written. This can be solved by opening the file in Notepad and deleting the last part written line.

An incorrectly formatted card will either not allow data to be written or will write corrupted files.

Very large files write data in large blocks, so if the card is removed without the logging being stopped and the file closed, then a lot more data than the last line will be lost.

How can I recover lost data?

If you have lost or corrupted data, there is a good chance of recovering it.

The way to do this is to put the card into a card reader, and right click on the flash disk icon in My Computer. Select 'Properties' and then click on the 'Tools' icon and then click 'Check now' under 'Error checking'.

Now click the boxes 'Automatically fix file system errors' and 'Scan for and attempt recovery of bad sectors', and then click 'Start'. This will go through the card and repair the FAT table and hopefully recover any lost data.

end faq

What are the power requirements and usage times for my VBOX equipment?

 

I get 'No response from VBOX', what does this mean?

This message will appear when the VBOXTools is trying to communicate with a VBOX but it has not detected any response from the VBOX. This could be due to one of the following:

• Incorrect Com port selection
• Cable unconnected or broken
• No power to the VBOX
• VBOX failure

 

What are the GPS Long Acc and GPS Latacc channels?

GPS Latacc and GPS longacc have been provided for when the VBOX is connected to a third party logger, or when the data is imported into third party software. Normally, longacc and latacc are calculated from velocity, heading and time, so these channels are not normally needed when using VBOX displays or VBOX Tools software.

Does VBOX software operate on a MAC?

Unfortunately, none of our software will run on Mac operating systems. This is something that we are looking into developing in the future.

There are a couple of ways to get around this (unfortunately both require installing Windows).

1. Boot Camp, which is provided by Apple. Boot Camp creates a partition on the hard disk where Windows is installed. You can choose Windows or OS10 upon start-up.
2. Parallel / Fusion – these allow Windows to be run as a programme in OS10. Once Windows is installed you can run our software as normal.

end faq