OpenIGTLink/ProtocolV2/Type/SensorData
Contents
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 | uint8 | Length of array (0-255) |
| UNIT 0 | uint64 | See bellow |
| NAMELEN 0 | uint8 | Name length |
| ... | ||
| FORMAT (NSENSORS-1) | ||
| LARRAY (NSENSORS-1) | int8 | Length of array (0-255) |
| UNIT (NSENSORS-1) | int64 | see bellow |
| NAMELEN (NSENSORS-1) | uint8 | Name length |
| NAME Table | ||
| NAME 0 | char[NAMELEN] | Name |
| ... | ||
| NAME (NSENSORS-1) | char[NAMELEN (NSENSORS-1)] | Name |
| Padding* | uint8 or none | padding to align DATA with WORD |
| 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) |
In C/C++, the size of padding is determined by:
(NAMELEN0 + NAMELEN1 + ... ) % 2 == 0) ? 0 : 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)
| Value | SI base unit name | Value | SI base unit name |
| 0x01 | meter | 0x05 | kelvin |
| 0x02 | gram | 0x06 | mole |
| 0x03 | second | 0x07 | candela |
| 0x04 | ampere | -- | -- |
| 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 | Exponent | Value | Exponent |
| 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
