如何理解This parameter is necessary to describe the bitposition of a signal within an SignalIPdu. It denotes the least significant bit for "Little Endian" and the most significant bit for "Big Endian" packed signals within the IPdu (see the description of the packingByteOrder attribute). In AUTOSAR the bit counting is always set to "sawtooth" and the bit order is set to "Decreasing". The bit counting in byte 0 starts with bit 0 (least significant bit). The most significant bit in byte 0 is bit 7. Please note that the way the bytes will be actually sent on the bus does not impact this representation: they will always be seen by the software as a byte array. If a mapping for the ISignalGroup is defined, this attribute is irrelevant and shall be ignored.

这段话指的是描述信号在SignalIPdu中的位位置的参数。它表示IPdu中“小端序”信号的最低有效位和“大端序”信号的最高有效位（请参见packingByteOrder属性的描述）。在AUTOSAR中，位计数始终设置为“锯齿形”，位顺序设置为“递减”。在字节0中的位计数从位0（最低有效位）开始。字节0中的最高有效位为位7。请注意，实际发送到总线上的字节方式不会影响这种表示：它们始终会被软件视为字节数组。如果定义了ISignalGroup的映射，则该属性无关紧要，应将其忽略。简单来说，这段话是在描述信号位位置的配置参数以及如何理解位计数和位顺序。