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RACELOGIC Support Centre

Serial (RS232) Protocol


VBOX 3i Product Range

 The following information relates to VBOX 3i products.

The VBOX units output the serial protocol through the RS232/CAN port, the USB port and via Bluetooth.

The RS232 output protocol is 115200 Baud, no parity, 8 data bits, 1 stop bit.

Note: The USB and Bluetooth options can output the messages in the full 100 Hz bandwidth, while the RS232 port has limitationsDue to the max bandwidth being 115200, live data transfer of all channels is limited to 20 Hz. 50 Hz should only be used to transmit standard GPS channels and Solution Type, and 100 Hz can only transmit Sats, Time, Speed, and Trigger Event Time. Logging too many channels at too high a rate will cause drop-outs and loss of data. For maximum accuracy, you should log tests performed at a GPS sample rate of more than 20 Hz to a compact flash card and do a post-process analysis. 

Serial String Format

Message format: 


The $VBOX3i and commas are in ASCII, the rest is in binary. 

The byte ordering format is big-endian (Motorola). 

Although not all of the channels listed below are present in the serial stream by default (you can select them in the VBOX Setup software), the following table shows the order in which they will appear in the data stream.

Click on the highlighted descriptions to see the specifications for each channel. 

Note: If you are using VBOX 3i Firmware Version 3.0 or later, you can find more information about selecting channels to send over serial here.

Enter first 4 bytes (nnnn) as 8 characters of hexadecimal:  

Part of String Type Bytes Description nnnn,
bit mask
nnnn   4 Reserved to indicate channel presence  
0000   4 Reserved  
s Integer 1


Numerical value

ttt Integer 3

UTC Time


aaaa Signed 4 Latitude

(MMMM.MMMMM * 100,000)

Signed Integer of Decimal Minutes *100,000.

Positive = North, Negative = South

oooo Signed 4 Longitude

(MMMMM.MMMMM * 100,000)

Signed Integer of Decimal Minutes *100,000.

Positive = West, Negative = East

vv Integer 2


Knots * 100

hh Integer 2


Degrees from True North * 100

eee Integer 3


Altitude in metres WGS84 * 100

True signed 24 bit number

zz Signed 2

Vertical Velocity

 m/s * 100

yy Signed 2

Lateral Acceleration (GPS)

g * 100

xx Signed 2

Longitudinal Acceleration (GPS)

g * 100

ffff Integer 4

Brake Distance

m *12800

jjjj Integer 4


Distance from power on, m *12800

1111 Float 4 Internal analogue ch1 0x00001000
2222 Float 4 Internal analogue ch2 0x00002000
3333 Float 4 Internal analogue ch3 0x00004000
4444 Float 4 Internal analogue ch4 0x00008000
l Integer 1

GLONASS satellites*

p Integer 1

GPS satellites

Numerical value

dd   2 Reserved 0x00040000
dd   2 Reserved 0x00080000
dd   2 Reserved 0x00100000
qq Integer 2 VBOX Serial Number 0x00200000
rr Integer 2

Kalman Filter Status

Numerical value

ii Integer 2

Solution Type

Numerical value

7777 Integer 4 Velocity Quality 0x01000000
8888 Signed 4 Reserved 0x02000000
kk Integer 2 Reserved 0x04000000
mmm Integer 3 Reserved 0x08000000
gggg Float 4 Event time 0x10000000
55 Float 2 Reserved 0x20000000
99 Integer 2 Reserved 0x40000000
66 Integer 2 Reserved 0x80000000
cc   2 Checksum  

*This channel is not available on VBOX 3i ADAS units.

NEWPOS Serial String Format

This is a message that contains additional channels to the serial message. Information in this message will provide you with an exact position in Longitude and Latitude. 

If your VBOX 3i unit has RTK enabled and configured for 2cm DGPS (CMR, RTCM V3, NTRIP), and you have set either the Latitude or Longitude channel to be sent over serial, the NEWPOS message will be added to the serial string and the data stream will look like the following example:



$NEWPOS,aaaaaaaabbbbbbbbcc is the additional exact Longitude and Latitude information to the serial data stream.

Part of string Bytes Description
$NEWPOS 7 String header
, 1 comma separator
aaaaaaaa 8 Longitude
64-bit float. little-endian (Intel).
The least-significant byte is stored first.
bbbbbbbb 8 Latitude
64-bit float.
cc 2 Checksum
NEWCAN Serial String Format

This is a message that contains additional channels to the serial message. Information in this message can be linked to anything that is not covered in standard serial, such as modules, ADAS channels, etc. This information is either configured in the setup software or requested by VBOX Test Suite.

You can use VBOX Setup to configure additional channels, by adding modules, CAN channels, and ADAS systems and by ticking the advanced box and selecting send to serial.

When any of these channels are selected to be present in the Serial data stream the data stream will look like the following example:



$NEWCAN,####,1111.....wwwwzz  is the additional CAN channel information to the serial data stream.

Note: 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 Channel 4 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 is in a standard IEEE 32-bit Float format.

The byte ordering format is big-endian (Motorola). 

Part of string Bytes Description ####,
bit mask
$NEWCAN 7 String header  
#### 4 Reserved to indicate channel presence  
, 1 comma separator  
1111 4 Additional Channel 1 0x00000001
2222 4 Additional Channel 2 0x00000002
3333 4 Additional Channel 3 0x00000004
4444 4 Additional Channel 4 0x00000008
5555 4 Additional Channel 5 0x00000010
6666 4 Additional Channel 6 0x00000020
7777 4 Additional Channel 7 0x00000040
8888 4 Additional Channel 8 0x00000080
9999 4 Additional Channel 9 0x00000100
aaaa 4 Additional Channel 10 0x00000200
bbbb 4 Additional Channel 11 0x00000400
cccc 4 Additional Channel 12 0x00000800
dddd 4 Additional Channel 13 0x00001000
eeee 4 Additional Channel 14 0x00002000
ffff 4 Additional channel 15 0x00004000
gggg 4 Additional Channel 16 0x00008000
hhhh 4 Additional Channel 17 0x00010000
iiii 4 Additional Channel 18 0x00020000
jjjj 4 Additional Channel 19 0x00040000
kkkk 4 Additional Channel 20 0x00080000
llll 4 Additional Channel 21 0x00100000
mmmm 4 Additional Channel 22 0x00200000
nnnn 4 Additional Channel 23 0x00400000
oooo 4 Additional Channel 24 0x00800000
pppp 4 Additional Channel 25 0x01000000
qqqq 4 Additional Channel 26 0x02000000
rrrr 4 Additional Channel 27 0x04000000
ssss 4 Additional Channel 28 0x08000000
tttt 4 Additional Channel 29 0x10000000
uuuu 4 Additional Channel 30 0x20000000
vvvv 4 Additional Channel 31 0x40000000
wwww 4 Additional Channel 32 0x80000000
zz 2 Checksum  


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