Class ScalingField

scapy/fields.py:3696–3736

Handle physical values which are scaled and/or offset for communication Example: >>> from scapy.packet import Packet >>> class ScalingFieldTest(Packet): fields_desc = [ScalingField('data', 0, scaling=0.1, offset=-1, unit='mV')] # noqa: E501

class ScalingField(_ScalingField,
                   Field[Union[int, float], Union[int, float]]):
    """ Handle physical values which are scaled and/or offset for communication

       Example:
           >>> from scapy.packet import Packet
           >>> class ScalingFieldTest(Packet):
                   fields_desc = [ScalingField('data', 0, scaling=0.1, offset=-1, unit='mV')]  # noqa: E501
           >>> ScalingFieldTest(data=10).show2()
           ###[ ScalingFieldTest ]###
             data= 10.0 mV
           >>> hexdump(ScalingFieldTest(data=10))
           0000  6E                                               n
           >>> hexdump(ScalingFieldTest(data=b"\x6D"))
           0000  6D                                               m
           >>> ScalingFieldTest(data=b"\x6D").show2()
           ###[ ScalingFieldTest ]###
             data= 9.9 mV

        bytes(ScalingFieldTest(...)) will produce 0x6E in this example.
        0x6E is 110 (decimal). This is calculated through the scaling factor
        and the offset. "data" was set to 10, which means, we want to transfer
        the physical value 10 mV. To calculate the value, which has to be
        sent on the bus, the offset has to subtracted and the scaling has to be
        applied by division through the scaling factor.
        bytes = (data - offset) / scaling
        bytes = ( 10  -  (-1) ) /    0.1
        bytes =  110 = 0x6E

        If you want to force a certain internal value, you can assign a byte-
        string to the field (data=b"\x6D"). If a string of a bytes object is
        given to the field, no internal value conversion will be applied

       :param name: field's name
       :param default: default value for the field
       :param scaling: scaling factor for the internal value conversion
       :param unit: string for the unit representation of the internal value
       :param offset: value to offset the internal value during conversion
       :param ndigits: number of fractional digits for the internal conversion
       :param fmt: struct.pack format used to parse and serialize the internal value from and to machine representation # noqa: E501
       """


class BitScalingField(_ScalingField, BitField):  # type: ignore