The RS232 output is present to provide a connection to a computer for configuring the settings of the VBOX 3iS through VBOX Setup software. It also can output NMEA format messages.
RS232 Racelogic Data Format
Protocol:
115200 Baud, no parity, 8 data bits, 1 stop bit
Message format:
$VB3is$glbtttaaaaoooovvvhhAAAVVVDspprrSSHHPPRRyyxxYYzzddTTTkkqQQT1T1wwwWWWiicc
| Parameter | Number of bytes | Description |
|---|---|---|
| $VB3is$ | 7 | Header |
| g | 1 | GPS sats Number of GPS satellites used |
| l | 1 | GLONASS sats Number of GLONASS satellites used |
| b | 1 | BeiDou sats Number of BeiDou satellites used |
| ttt | 3 (MSB first) | Time Ticks since midnight UTC, incrementing every 10 ms |
| aaaa | 4 (MSB first) | Latitude Signed integers, 0.0000001° per bit |
| oooo | 4 (MSB first) | Longitude Signed integers, 0.0000001° per bit |
| vvv | 3 (MSB first) | Velocity 0.001 km/h per bit |
| hh | 2 (MSB first) | Heading 0.01° per bit |
| AAA | 3 (MSB first) | Altitude 0.01 m per bit |
| VVV | 3 (MSB first) | Vertical velocity 0.001 m/s per bit |
| s | 1 | Solution Type |
| pp | 2 (MSB first) | Pitch angle derived from KF 0.01° per bit |
| rr | 2 (MSB first) | Roll angle derived from KF 0.01° per bit |
| HH | 2 (MSB first) | Heading derived from KF 0.01° per bit |
| PP | 2 (MSB first) | Pitch rate derived from internal/external IMU 0.01°/sec per bit |
| RR | 2 (MSB first) | Roll rate derived from internal/external IMU 0.01°/sec per bit |
| yy | 2 (MSB first) | Yaw rate derived from internal/external IMU 0.01°/sec per bit |
| xx | 2 (MSB first) | X accel from internal/external IMU 0.01 m/s² per bit |
| YY | 2 (MSB first) | Y accel from internal/external IMU 0.01 m/s² per bit |
| zz | 2 (MSB first) | Z accel from internal/external IMU 0.01 m/s² per bit |
| dd | 2 (MSB first) | Date DOS format |
| TTT | 3 (MSB first) | Trigger event time 0.000001 ms per bit |
| kk | 2 (MSB first) | Kalman Filter Status |
| q | 1 | Position Quality |
| 2 (MSB first) | Speed Quality 0.001 m/s per bit |
|
| T1T1 | 2 (MSB first) | T1 0.0000001 ms per bit |
| www | 3 (MSB first) | Wheel speed 1 0.001 m/s per bit |
| WWW | 3 (MSB first) | Wheel speed 2 0.001 m/s per bit |
| ii | 2 (MSB first) | Heading_IMU2 derived from KF 0.01° per bit |
| cc | 2 (MSB first) | Checksum See CRC Calculation example below |
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;
NMEA Output (RLS)
The VBOX 3iS can output 6 types of NMEA messages, the contents of RLS are shown below.
$PTPSR,RLS,V,hhmmss.ss,IMUheading,IMUpitch,IMUroll,IMU3Dquality*cs
| Name | ASCII String | Units | Description | ||
|---|---|---|---|---|---|
| Format | Example | ||||
| $PTPSR | string | $PTPSR | Message ID | ||
| RLS | string | RLS | Sentence formatter | ||
| V | character | V | Whether the UTC time is valid | V=valid or N=not valid | |
| hhmmss.ss | hhmmss.ss | 114105.00 | UTC Time | Current time | |
| IMUheading | string | 157.531 | Degrees | Heading angle of IMU | |
| IMUpitch | string | 002.473 | Degrees | Pitch angle of IMU | |
| IMUroll | string | -02.635 | Degrees | Roll angle of IMU | |
| IMU3Dquality | string | 000.192 | 3D quality of IMU | ||
| cs | hexadecimal | *5F | Checksum | ||