OpenIGTLink/ProtocolV2/Type/SensorData

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Summary

SDATA is a message type, which is used to transfer sensor reading, 3-axis position, velocity, acceleration, angle, angle velocity and angle acceleration. The message format is intended for manipulator control and various types of sensors.

Message Types

SENSOR

Data	Type	Description
NSENSORS	uint16	Number of sensors
FORMAT 0
LARRAY 0	uint16	Length of array (0-255)
UNIT 0	int64	See bellow
NAME 0	char[20]	Name
...
FORMAT (NSENSORS-1)
LARRAY (NSENSORS-1)	int8	Length of array (0-255)
UNIT (NSENSORS-1)	int64	see bellow
NAME (NSENSORS-1)	char[20]	Name
DATA
DATA 0	float64[LARRAY 0]	value array for sensor 0
DATA 1	float64[LARRAY 1]	value array for sensor 1
...
DATA (NSENSORS-1)	float64[LARRAY (NSENSORS-1)]	value array for sensor (NSENSORS-1)

Definition of UNIT field

UNIT is a 64-bit field to specify a unit consisting of SI-prefix (e.g. milli, micro, kilo etc...) and combination of SI-base and/or SI-derived unites.

 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...
 |PREFIX |   UNIT0   |  EXP0 |   UNIT1   |  EXP1 |   UNIT2   | EXP2
 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...
 0               1               2               3               4 

    ...-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       EXP2 |   UNIT3   |  EXP3 |   UNIT4   |  EXP4 |   UNIT5   |  EXP5 |
    ...-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        4               5               6               7

PREFIX (4bit)

Value	SI-prefix	Value	SI-prefix
0x0	None	--	--
0x1	deka (deca) (1e1)	0x9	deci (1e-1)
0x2	hecto (1e2)	0xA	centi (1e-2)
0x3	kilo (1e3)	0xB	milli (1e-3)
0x4	mega (1e6)	0xC	micro (1e-6)
0x5	giga (1e9)	0XD	nano (1e-9)
0x6	tera (1e12)	0XE	pico (1e-12)
0x7	peta (1e15)	0XF	femto (1e-15)

UNIT(6bit)

SI base units

Value	SI base unit name	Value	SI base unit name
0x01	meter	0x05	kelvin
0x02	gram	0x06	mole
0x03	second	0x07	candela
0x04	ampere	--	--

SI derived units

Value	Unit name	dimension	Value	Unit name	dimension
0x08	radian	meter/meter	0x12	ohm	meter^2-kilogram/second^3-ampere^2
0x09	steradian	meter^2/meter^2	0x14	siemens	second^3-ampere^2/meter^2-kilogram
0x0A	hertz	/second	0x15	weber	meter^2-kilogram/second^2-ampere
0x0B	newton	meter-kilogram/second^2	0x16	tesla	kilogram/second^2-ampere
0x0C	pascal	kilogram/meter-second^2	0x17	henry	meter^2-kilogram/second^2-ampere^2
0x0D	joule	meter^2-kilogram/second^2	0x18	lumen	candela-steradian
0x0E	watt	meter^2-kilogram/second^3	0x19	lux	candela-steradian/meter^2
0x0F	coulomb	second-ampere	0x1A	becquerel	/second
0x10	volt	meter^2-kilogram/second^3-ampere	0x1B	gray	meter^2/second^2
0x11	farad	second^4-ampere^2/meter^2-kilogram	0x1C	sievert	meter^2/second^2

EXP (4-bit)

Value	SI-prefix	Value	SI-prefix
0x0	^0	--	--
0x1	^1	0xF	^-1
0x2	^2	0xE	^-2
0x3	^3	0xD	^-3
0x4	^4	0xC	^-4
0x5	^5	0XB	^-5
0x6	^6	0XA	^-6
0x7	^7	0X9	^-7

Examples

Sending 3-axis position

A device with 3-axis force (N), 3-axis torque (N*m) and 3-axis acceleration (mm/s^2) sensors is sending data to a data logger program. The names of the sensors are "FORCE", "TORQUE", and "ACCEL." The message structure may be as follows:

Data	Type	Value
NSENSORS	uint16	3
LARRAY 0	uint8	3
PREFIX 0	int8	0
DIMENSION 0	uint8[6]	0x58 0x00 0x00 0x00 0x00 0x00 (N)
NAME0	char[20]	"FORCE"
LARRAY 1	uint8	3
PREFIX 1	int8	0
DIMENSION 1	uint8[6]	0x58 0x08 0x00 0x00 0x00 0x00 (N*m)
NAME 1	char[20]	"TORQUE"
LARRAY 2	uint8	3
PREFIX 2	int8	0
DIMENSION 2	uint8[6]	0x08 0x03 0x00 0x00 0x00 0x00 (m/s^2)
NAME 2	char[20]	"ACCEL"
DATA 0	double[3]	{0.0, 0.0, 0.0}
DATA 1	double[3]	{0.0, 0.0, 0.0}
DATA 2	double[3]	{0.0, 0.0, 0.0}

GET_SENSOR

Data

Type

Description

STT_SENSOR

N/A

STP_SENSOR

N/A

RTS_SENSOR

N/A

Implementations

The TDATA message type is implemented in the following source code.

Contributors

Junichi Tokuda, Yuichiro Hayashi