General types, enums, values definitions that are used across the sbgECom protocol documentation and sbgECom C library implementation.

Endianness

The sbgECom binary protocol uses the little-endian data format.
However, some third-party binary messages may use the big-endian format. These instances are explicitly noted in this documentation.

The sbgECom communication library is designed to be compatible with both little-endian and big-endian platforms.
You can configure the host platform's endianness by setting the macro SBG_CONFIG_BIG_ENDIAN to 1.

Note: For ASCII or NMEA messages, the platform's endianness does not impact the parsing or generation of these messages.

Types Definitions

This section defines common types that are using through the documentation and protocol.

Scalar Types

The following fundamental scalar types are used throughout the protocol documentation:

Type	Description
Mask	An unsigned integer variable used to store a set of bit masks.
Enum	A set of named integer values representing a status or state.
bool	8-bit boolean; `0x00` is FALSE, `0x01` is TRUE.
uint8	8-bit unsigned integer.
int8	8-bit signed integer.
uint16	16-bit unsigned integer.
int16	16-bit signed integer.
uint32	32-bit unsigned integer.
int32	32-bit signed integer.
uint64	64-bit unsigned integer.
int64	64-bit signed integer.
float	32-bit single-precision floating point, standard IEEE 754 format.
double	64-bit double-precision floating point, standard IEEE 754 format.
void[]	Data buffer with variable length.
string	Null-terminated ASCII C string. The maximum size of the string is defined in the message.

Note: The Mask and Enum types do not have a predefined size in bytes. Refer to the specific message or command payload documentation for the corresponding size.; The [] symbol denotes an array of scalar types. For example, float[] indicates an array of single-precision floating point values.

Mathematical Types

Please find below the documentation for 3D mathematical vectors and 3x3 matrices used through the protocol documentation:

Vector Objects

Vectors are stored as a 1D array of float or double components, with the components arranged sequentially in memory.

Mathematically, a 3D vector V with components x, y, z can be represented as:

    / x \
V = | y |
    \ z /

In memory, the vector is stored as:

[x, y, z]

Matrix Objects

Matrices are stored as a 1D array of float or double elements, organized in a column-major format.
This means that the elements of the matrix are stored in memory column by column.

For example, a 3x3 matrix M with elements a_ij (where i is the row index and j is the column index) is represented as:

    / a11  a12  a13 \
M = | a21  a22  a23 |
    \ a31  a32  a33 /

In memory, this matrix is stored as:

[a11, a21, a31, a12, a22, a32, a13, a23, a33]

In this layout, the first three elements correspond to the first column of the matrix, the next three elements correspond to the second column, and the last three elements correspond to the third column.

Version/Revision Type

Some commands and messages contain version/revision numbers encoded as 32-bit unsigned integers.
These are used to track different versions of hardware and software components.

There are two schemes, each with distinct usage and interpretation:

Basic Revision: Used for hardware revisions, following a simple A.B.C.D format.
Software Version: Used for firmware and software, following a Major.Minor.Build-Qualifier format.

The most significant bit (MSB) of the version number determines the scheme in use:

MSB = 0: Indicates the basic revision scheme.
MSB = 1: Indicates the software version scheme.

Basic Revision Scheme

This scheme follows the A.B.C.D format and is used for versioning hardware and components, excluding firmware or software.

The basic revision scheme is organized in memory as follows:

Field	Size (bits)	Definition
SCHEME	1 (MSB)	Set to 0 for basic revision scheme.
A	7	A version number (0 to 127).
B	8	B version number (0 to 255).
C	8	C version number (0 to 255).
D	8	D version number (0 to 255).

Note: It is common to use only A.B as Major.Minor for hardware revisions, leaving C.D as zero.

Software Version Scheme

This scheme uses the Major.Minor.Build-Qualifier format and applies to all firmware and software items.

The software version scheme is organized in memory as follows:

Field	Size (bits)	Definition
SCHEME	1 (MSB)	Set to 1 for software version scheme.
QUALIFIER	3	Software release qualifier (see VERSION_QUALIFIER).
MAJOR	6	Major version number (0 to 63).
MINOR	6	Minor version number (0 to 63).
BUILD	16	Build number (0 to 65535).

Version Qualifier Enum

The QUALIFIER field indicates the build type for a firmware release:

Name	Value	Description
SBG_VERSION_QUALIFIER_DEV	0	Development build (pre-alpha). Used for testing new technologies.
SBG_VERSION_QUALIFIER_ALPHA	1	Alpha version, may be unstable, missing features, API can change.
SBG_VERSION_QUALIFIER_BETA	2	Beta version, feature-freeze, can be unstable, API should not change.
SBG_VERSION_QUALIFIER_RC	3	Release Candidate, feature-freeze, no known bugs, API is stable.
SBG_VERSION_QUALIFIER_STABLE	4	Stable release, suitable for production environments.
SBG_VERSION_QUALIFIER_HOT_FIX	5	Bug fixes applied to a stable version, under validation before releasing a new stable build.

IPv4 Address Type

The sbgECom protocol defines the type sbgIpAddress to handle an IPv4 address.
The underlying type is a uint32 that stores the four 8-bit IP address fields in big-endian order to comply with Ethernet endianness.

As a result, the IP address 192.168.1.2 (A.B.C.D) is organized in memory as follows:

Little Endian Platform

Byte Index	0 (LSB)	1	2	3 (MSB)
Decimal	192	168	1	2
Hex	0xC0	0xA8	0x01	0x02

uint32 value: 33 663 168 (in decimal).

Big Endian Platform

Byte Index	0 (MSB)	1	2	3 (LSB)
Decimal	192	168	1	2
Hex	0xC0	0xA8	0x01	0x02

uint32 value: 3 232 235 778 (in decimal).

Error Code Enumeration

Through the protocol documentation and sbgECom library implementation, the following error codes are being used:

Error Code	Value	Description
SBG_NO_ERROR	0	The command has been properly executed.
SBG_ERROR	1	Command could not be executed properly due to a generic error.
SBG_NULL_POINTER	2	A pointer is null and it is not expected.
SBG_INVALID_CRC	3	A frame with an invalid CRC has been received.
SBG_INVALID_FRAME	4	The received frame is invalid and mal-formatted.
SBG_TIME_OUT	5	An operation has timed out and no answer has been received.
SBG_WRITE_ERROR	6	Some data couldn't be written over an interface (serial/file/ethernet).
SBG_READ_ERROR	7	Some data couldn't be read over an interface (serial/file/ethernet).
SBG_BUFFER_OVERFLOW	8	A buffer is too small to contain so much data.
SBG_INVALID_PARAMETER	9	A parameter has a non valid value.
SBG_NOT_READY	10	An operation or request couldn't be completed such as no data received or device is busy.
SBG_MALLOC_FAILED	11	Failed to allocate a buffer (out of memory).
SBG_DEVICE_NOT_FOUND	16	A resource or device couldn't be found.
SBG_OPERATION_CANCELLED	17	An operation has been cancelled by the user.
SBG_NOT_CONTINUOUS_FRAME	18	We have received a frame that is part of a sequence but are missing the end.
SBG_INCOMPATIBLE_HARDWARE	19	The command cannot be executed because of hardware incompatibility.
SBG_INVALID_VERSION	20	Command cannot be executed because of software incompatibility.

Conventions & Units

SBG Systems IMU, AHRS and INS devices adhere to the International System of Units (SI) where applicable.
The device coordinate frame is defined as North East Down (NED).

Physical Quantity	Unit Description
Angle	Radians (rad), representing roll, pitch, and yaw.
Rotational Speed	Radians per second (rad/s or rad.s⁻¹).
Acceleration	Meters per second squared (m/s² or m.s⁻²).
Velocity	Meters per second (m/s or m.s⁻¹).
Latitude	Degrees, positive values indicate North, negative values indicate South.
Longitude	Degrees, positive values indicate East, negative values indicate West.
Altitude	Meters, altitude above Mean Sea Level (MSL), positive upward.
Height	Meters, height above the WGS-84 Ellipsoid, positive upward.
Heave	Vertical displacement, positive downward.
Surge	Longitudinal displacement, positive toward the vessel's bow.
Sway	Transverse displacement, positive toward the vessel's starboard side.

GNSS Definitions

This section covers common definitions related to GNSS used by the sbgECom binary protocol.

Constellations

Below are the enum definitions for all GNSS constellations.

Enum	Value	Description
SBG_ECOM_CONSTELLATION_ID_UNKNOWN	0	Unknown
SBG_ECOM_CONSTELLATION_ID_GPS	1	GPS
SBG_ECOM_CONSTELLATION_ID_GLONASS	2	GLONASS
SBG_ECOM_CONSTELLATION_ID_GALILEO	3	Galileo
SBG_ECOM_CONSTELLATION_ID_BEIDOU	4	BeiDou
SBG_ECOM_CONSTELLATION_ID_QZSS	5	QZSS
SBG_ECOM_CONSTELLATION_ID_SBAS	6	SBAS
SBG_ECOM_CONSTELLATION_ID_IRNSS	7	IRNSS
SBG_ECOM_CONSTELLATION_ID_LBAND	8	L-Band

Satellite Id

The sbgECom protocol uses the RINEX satellite Id definition to identify each space vehicle tracked by a GNSS receiver.
The satellite Id definition depends on the GNSS constellation:

PRN for GPS, Galileo, BeiDou, IRNSS
Slot number for GLONASS
PRN-100 for SBAS
PRN-192 for QZSS

Signals

Below are the enum definitions for GNSS signals.

GPS constellation (10 to 39)

Enum	Value
SBG_ECOM_SIGNAL_ID_UNKNOWN	0
SBG_ECOM_SIGNAL_ID_GPS_L1C_DP	10
SBG_ECOM_SIGNAL_ID_GPS_L1C_D	11
SBG_ECOM_SIGNAL_ID_GPS_L1C_P	12
SBG_ECOM_SIGNAL_ID_GPS_L1_W	13
SBG_ECOM_SIGNAL_ID_GPS_L1_CA	14
SBG_ECOM_SIGNAL_ID_GPS_L1P	15
SBG_ECOM_SIGNAL_ID_GPS_L1_PY	16
SBG_ECOM_SIGNAL_ID_GPS_L1M	17
SBG_ECOM_SIGNAL_ID_GPS_L2C_ML	18
SBG_ECOM_SIGNAL_ID_GPS_L2C_L	19
SBG_ECOM_SIGNAL_ID_GPS_L2_SEMICL	20
SBG_ECOM_SIGNAL_ID_GPS_L2_W	21
SBG_ECOM_SIGNAL_ID_GPS_L2_CA	22
SBG_ECOM_SIGNAL_ID_GPS_L2C_M	23
SBG_ECOM_SIGNAL_ID_GPS_L2_PY	24
SBG_ECOM_SIGNAL_ID_GPS_L2M	25
SBG_ECOM_SIGNAL_ID_GPS_L2P	26
SBG_ECOM_SIGNAL_ID_GPS_L5_IQ	27
SBG_ECOM_SIGNAL_ID_GPS_L5_I	28
SBG_ECOM_SIGNAL_ID_GPS_L5_Q	29

GLONASS constellation (40 to 59)

Enum	Value
SBG_ECOM_SIGNAL_ID_GLONASS_G1_P	40
SBG_ECOM_SIGNAL_ID_GLONASS_G1_CA	41
SBG_ECOM_SIGNAL_ID_GLONASS_G2_P	42
SBG_ECOM_SIGNAL_ID_GLONASS_G2_CA	43
SBG_ECOM_SIGNAL_ID_GLONASS_G3_I	44
SBG_ECOM_SIGNAL_ID_GLONASS_G3_Q	45
SBG_ECOM_SIGNAL_ID_GLONASS_G3_IQ	46

Galileo constellation (60 to 99)

Enum	Value
SBG_ECOM_SIGNAL_ID_GALILEO_E1_BC	60
SBG_ECOM_SIGNAL_ID_GALILEO_E1_C	61
SBG_ECOM_SIGNAL_ID_GALILEO_E1_B	62
SBG_ECOM_SIGNAL_ID_GALILEO_E1_A	63
SBG_ECOM_SIGNAL_ID_GALILEO_E1_ABC	64
SBG_ECOM_SIGNAL_ID_GALILEO_E5B_IQ	65
SBG_ECOM_SIGNAL_ID_GALILEO_E5B_I	66
SBG_ECOM_SIGNAL_ID_GALILEO_E5B_Q	67
SBG_ECOM_SIGNAL_ID_GALILEO_E5A_IQ	68
SBG_ECOM_SIGNAL_ID_GALILEO_E5A_I	69
SBG_ECOM_SIGNAL_ID_GALILEO_E5A_Q	70
SBG_ECOM_SIGNAL_ID_GALILEO_E5_IQ	71
SBG_ECOM_SIGNAL_ID_GALILEO_E5_I	72
SBG_ECOM_SIGNAL_ID_GALILEO_E5_Q	73
SBG_ECOM_SIGNAL_ID_GALILEO_E6_BC	74
SBG_ECOM_SIGNAL_ID_GALILEO_E6_C	75
SBG_ECOM_SIGNAL_ID_GALILEO_E6_B	76
SBG_ECOM_SIGNAL_ID_GALILEO_E6_ABC	77
SBG_ECOM_SIGNAL_ID_GALILEO_E6_A	78

Beidou constellation (100 to 149)

Enum	Value
SBG_ECOM_SIGNAL_ID_BEIDOU_B1IQ	100
SBG_ECOM_SIGNAL_ID_BEIDOU_B1I	101
SBG_ECOM_SIGNAL_ID_BEIDOU_B1Q	102
SBG_ECOM_SIGNAL_ID_BEIDOU_B1C_P	103
SBG_ECOM_SIGNAL_ID_BEIDOU_B1C_DP	104
SBG_ECOM_SIGNAL_ID_BEIDOU_B1C_D	105
SBG_ECOM_SIGNAL_ID_BEIDOU_B1A_P	106
SBG_ECOM_SIGNAL_ID_BEIDOU_B1A_DP	107
SBG_ECOM_SIGNAL_ID_BEIDOU_B1A_D	108
SBG_ECOM_SIGNAL_ID_BEIDOU_B2IQ	109
SBG_ECOM_SIGNAL_ID_BEIDOU_B2I	110
SBG_ECOM_SIGNAL_ID_BEIDOU_B2A_P	111
SBG_ECOM_SIGNAL_ID_BEIDOU_B2A_DP	112
SBG_ECOM_SIGNAL_ID_BEIDOU_B2A_D	113
SBG_ECOM_SIGNAL_ID_BEIDOU_B2Q	114
SBG_ECOM_SIGNAL_ID_BEIDOU_B2B_P	115
SBG_ECOM_SIGNAL_ID_BEIDOU_B2B_DP	116
SBG_ECOM_SIGNAL_ID_BEIDOU_B2B_D	117
SBG_ECOM_SIGNAL_ID_BEIDOU_B2AB_P	118
SBG_ECOM_SIGNAL_ID_BEIDOU_B2AB_DP	119
SBG_ECOM_SIGNAL_ID_BEIDOU_B2AB_D	120
SBG_ECOM_SIGNAL_ID_BEIDOU_B3IQ	121
SBG_ECOM_SIGNAL_ID_BEIDOU_B3I	122
SBG_ECOM_SIGNAL_ID_BEIDOU_B3Q	123
SBG_ECOM_SIGNAL_ID_BEIDOU_B3A_D	124
SBG_ECOM_SIGNAL_ID_BEIDOU_B3A_P	125
SBG_ECOM_SIGNAL_ID_BEIDOU_B3A_DP	126

QZSS constellation (150 to 179)

Enum	Value
SBG_ECOM_SIGNAL_ID_QZSS_L1C_DP	150
SBG_ECOM_SIGNAL_ID_QZSS_L1C_D	151
SBG_ECOM_SIGNAL_ID_QZSS_L1C_P	152
SBG_ECOM_SIGNAL_ID_QZSS_L1_CA	153
SBG_ECOM_SIGNAL_ID_QZSS_L1_SAIF	154
SBG_ECOM_SIGNAL_ID_QZSS_L1_SB	155
SBG_ECOM_SIGNAL_ID_QZSS_L2C_ML	156
SBG_ECOM_SIGNAL_ID_QZSS_L2C_L	157
SBG_ECOM_SIGNAL_ID_QZSS_L2C_M	158
SBG_ECOM_SIGNAL_ID_QZSS_L5_IQ	159
SBG_ECOM_SIGNAL_ID_QZSS_L5_I	160
SBG_ECOM_SIGNAL_ID_QZSS_L5_Q	161
SBG_ECOM_SIGNAL_ID_QZSS_L5S_IQ	162
SBG_ECOM_SIGNAL_ID_QZSS_L5S_I	163
SBG_ECOM_SIGNAL_ID_QZSS_L5S_Q	164
SBG_ECOM_SIGNAL_ID_QZSS_L6_P	165
SBG_ECOM_SIGNAL_ID_QZSS_L6_DP	166
SBG_ECOM_SIGNAL_ID_QZSS_L6_D	167
SBG_ECOM_SIGNAL_ID_QZSS_L6_E	168
SBG_ECOM_SIGNAL_ID_QZSS_L6_DE	169

SBAS system (180 to 199)

Enum	Value
SBG_ECOM_SIGNAL_ID_SBAS_L1_CA	180
SBG_ECOM_SIGNAL_ID_SBAS_L5_I	181
SBG_ECOM_SIGNAL_ID_SBAS_L5_Q	182
SBG_ECOM_SIGNAL_ID_SBAS_L5_IQ	183

IRNSS / NAVIC constellation (200 to 219)

Enum	Value
SBG_ECOM_SIGNAL_ID_IRNSS_L5_A	200
SBG_ECOM_SIGNAL_ID_IRNSS_L5_B	201
SBG_ECOM_SIGNAL_ID_IRNSS_L5_C	202
SBG_ECOM_SIGNAL_ID_IRNSS_L5_BC	203
SBG_ECOM_SIGNAL_ID_IRNSS_S9_A	204
SBG_ECOM_SIGNAL_ID_IRNSS_S9_B	205
SBG_ECOM_SIGNAL_ID_IRNSS_S9_C	206
SBG_ECOM_SIGNAL_ID_IRNSS_S9_BC	207

L-Band system (220 to 230)

Enum	Value
SBG_ECOM_SIGNAL_ID_LBAND	220