.. _headlabel-refx-data-143: Data 143 (Crash Sensor Data) ============================ Packets the acceleration data when the crash event is detected. .. note:: This data is only used for :ref:`Record 75H `. If another record carries this data, its 'Data Length' will always be 0. The frame format of the Data **143** unit is as follows: .. code-block:: none For example (Total 310 bytes): 80 8F 81 32 00 00 33 FF 01 2C 00 02 00 B7 08 5E 00 04 00 02 00 02 FF F5 00 B9 08 60 00 02 00 00 00 00 FF FD 00 C4 08 65 00 04 00 00 00 00 FF FA 00 B3 08 69 00 03 00 02 00 00 FF F6 00 B3 08 63 00 04 00 03 00 00 00 00 00 C3 08 4E 00 02 00 04 00 00 00 07 00 BE 08 55 00 04 00 02 00 01 00 02 00 BC 08 61 00 05 00 00 00 02 00 03 00 BE 08 60 00 03 FF FE 00 01 FF FE 00 BB 08 60 00 04 00 01 00 00 FF F4 00 BD 08 5B 00 01 FF FF 00 00 FF F3 00 B6 08 5E 00 02 00 00 00 00 FF F2 00 B6 08 56 00 01 00 01 00 00 FF F9 00 C1 08 66 00 01 00 00 00 01 00 00 00 C1 08 5E 00 02 00 03 00 00 FF F9 00 C0 08 5F 00 04 00 01 00 01 00 05 00 C3 08 61 00 00 00 00 00 00 00 06 00 B9 08 60 00 05 00 01 00 00 FF FA 00 BF 08 68 00 02 FF FF FF FF FF F7 00 BA 08 66 00 04 00 01 FF FE FF FF 00 BE 08 5E 00 02 00 00 00 00 FF FC 00 BE 08 66 00 03 00 01 00 02 FF F7 00 B8 08 5E 00 00 00 04 00 03 FF FE 00 C5 08 5E FF FE 00 04 00 02 00 03 00 BE 08 60 FF FF 00 03 00 02 .. tabularcolumns:: |p{3.2em}|p{11.2em}|p{5.8em}|p{13em}|p{5.8em}| .. table:: :width: 100% :widths: auto +---------+-------------------------------------+---------------+-------------------------------------------------+--------------+ | Parts | Fields | Length (Byte) | Range/Format | Default | +=========+=====================================+===============+=================================================+==============+ | ID | Data ID | 2 | 808FH (143) | 808FH (143) | +---------+-------------------------------------+---------------+-------------------------------------------------+--------------+ | Length | Data Length | 1 or 2 | 00H-7FH or 8080H-84B6H | | +---------+-------------------------------------+---------------+-------------------------------------------------+--------------+ | Content | `Crash ID` | 1 | 00H-FFH | | + +-------------------------------------+---------------+-------------------------------------------------+--------------+ | | `Data Type` | 1 | | | + +-------------------------------------+---------------+-------------------------------------------------+--------------+ | | `Acceleration Parameter` | 1 | | | + +-------------------------------------+---------------+-------------------------------------------------+--------------+ | | `Reserved` | 1 | 00H-FFH | FFH | + +-------------------------------------+---------------+-------------------------------------------------+--------------+ | | `Length` | 2 | 0000H-04B0H | | + +-------------------------------------+---------------+-------------------------------------------------+--------------+ | | `Data` | N | | | +---------+-------------------------------------+---------------+-------------------------------------------------+--------------+ - `Crash ID` When the terminal detects a crash event, it will automatically assign a crash ID. The ID is convenient to distinguish multiple adjacent crash events. It rolls from 00H to FFH. - `Data Type` The highest bit (bit7) represents the type of data recorded, the upper 3 bits (bit 6 to bit 4) are reserved, the next 3 bits (bit3 to bit1) represent the data sampling frequency, and the lowest bit (bit0) indicates the time of the data. Details are as follows: - **Type** (Bit7) - **0b0** - Acceleration data. - **Reserved** (Bit6 to Bit4) Reserved bits, set to 0b000 by default. - **Sensor Frequency** (Bit3 to Bit1) Indicates the sampling frequency of sensor data. - **0b000** - 100Hz. - **0b001** - 200Hz. - **Others** - Reserved. - **Time Point** (Bit0) - **0b0** - The data is recorded **before** crash. - **0b1** - The data is recorded **after** crash. - `Acceleration Parameter` The upper 4 bits represent the acceleration range, and the lower 4 bits represent the acceleration resolution. In particular, **FFH** means the terminal cannot obtain this information. - **Range** (Bit7 to Bit4) - **0b0000** - ±2g. - **0b0001** - ±4g. - **0b0010** - ±8g. - **0b0011** - ±16g. - **Others** - Reserved. - **Resolution** (Bit3 to Bit0) - **0b0000** - 0.98 mg/LSB. - **0b0001** - 1.95 mg/LSB. - **0b0010** - 3.91 mg/LSB. - **0b0011** - 7.81 mg/LSB. - **0b0100** - 0.06 mg/LSB. - **0b0101** - 0.12 mg/LSB. - **0b0110** - 0.24 mg/LSB. - **0b0111** - 0.49 mg/LSB. - **Others** - Reserved. - `Length` Indicates the total number of bytes in the 'Data' field. If the value is 0, the 'Data' field is absent. - `Data` This field consists of one or more sets of sensor raw data. If the highest bit of 'Data Type' is 0, then each set of sensor data is 3-axis data, if the highest bit of 'Data Type' is 1, then each set of sensor data is 6-axis data. For acceleration data, each data is a 16-bit signed integer (2 bytes). The acceleration resolution can be known from the 'Acceleration Parameter'. For example, if the resolution is 0.49 mg/LSB and the 16-bit signed integer is 0123H (i.e. 291), then the corresponding acceleration can be calculated to be 142.59 mg (291*0.49=142.59). The definition of a set of 3-axis data is as follow: - **A Set of 3-axis Data** Length: 6 bytes The 6 bytes represent 3-axis (X/Y/Z) acceleration data. The order is as follows: - **X-axis Acceleration** - 2 bytes. It is a 16-bit signed integer. - **Y-axis Acceleration** - 2 bytes. It is a 16-bit signed integer. - **Z-axis Acceleration** - 2 bytes. It is a 16-bit signed integer. For example, 0123F1003012H means that X-axis acceleration data is 291 (0123H), Y-axis acceleration data is -3840 (F100H) and Z-axis acceleration data is 12306 (3012H).