Lassen SQ, Справочное руководство

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Lassen SQ GPS Receiver 6 9
Trimble Standard Interface Protocol (TSIP) A
A.2
Packet Structure
TSIP packet structure is the same for both commands and reports. The
packet format is:
<DLE> <id> <data string bytes> <DLE> <ETX>
Where:
•
<DLE>
is the byte 0x10
•
<ETX>
is the byte 0x03
• <id> is a packet identifier byte, which can have any value
excepting
<ETX>
and
<DLE>
.
The bytes in the data string can have any value. To prevent confusion
with the frame sequences
<DLE> <
ID
>
and
<DLE> <ETX>
, every
<DLE>
byte in the data string is preceded by an extra
<DLE>
byte
('stuffing'). These extra
<DLE>
bytes must be added ('stuffed') before
sending a packet and removed after receiving the packet. Notice that a
simple
<DLE> <ETX>
sequence does not necessarily signify the end of
the packet, as these can be bytes in the middle of a data string. The end
of a packet is
<ETX>
preceded by an odd number of
<DLE>
bytes.
Multiple-byte numbers (integer, float, and double) follow the
ANSI/IEEE Std. 754 IEEE Standard for binary Floating-Point
Arithmetic. They are sent most-significant byte first. This may involve
switching the order of the bytes as they are normally stored in Intel
based machines. Specifically:
• UINT8 = Byte: An 8 bit unsigned integer.
• UINT16 = Word: A 16 bit unsigned integer.
• INT16 = I
nteger:
A 16 bit integer.
• INT32 = Long: A 32 bit integer.
• UINT32 = ULong: A 32 bit unsigned integer.
• Single — Float, or 4 byte REAL has a precision of 24
significant bits, roughly 6.5 digits.
• Double — 8 byte REAL has a precision of 52 significant bits. It
is a little better than 15 digits.