2.2.1 DRT Header
All DRT Messages use the following common header.
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1 |
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2 |
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3 |
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FieldID |
Length |
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Identifier |
VersionMajor |
VersionMinor |
MessageType |
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MessageID |
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FieldID (2 bytes): The type of message. It MUST be set to 0x0010 (DRT_HEADER).
Length (2 bytes): The length, in bytes, of the DRT Header. It MUST be set to 0x000C.
Identifier (1 byte): MUST be set to 0x51.
VersionMajor (1 byte): The major version of protocol, which is defined by the higher-layer application.
VersionMinor (1 byte): The minor version of protocol, which is defined by the higher-layer application.
MessageType (1 byte): The type of message following the DRT Header. It MUST be one of the following:
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Value
Meaning
0x01
0x02
0x03
0x04
0x07
0x08
0x09
0x0B
MessageID (4 bytes): A random number message identifier used for acknowledgment tracking. This number is generated by the protocol; the algorithm used to generate the MessageID MUST minimize the probability of duplicate MessageIDs within a window of time at least as large as the round-trip latency of a protocol message.