Novatel GPStation-6, Руководство пользователя

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33
GPStation-6 User Manual Rev 2
Messages
3.3 ASCII
ASCII messages are readable by both the user and a computer. The structures of all ASCII messages
follow the general conventions as noted here:
1. The lead code identifier for each record is '#'.
2. Each log or command is of variable length depending on amount of data and formats.
3. All data fields are delimited by a comma ',' with two exceptions:
• The first exception is the last header field which is followed by a ‘;’ to denote the
start of the data message.
• The second exception is the last data field, which is followed by a * to indicate end
of message data.
4. Each log ends with a hexadecimal number preceded by an asterisk and followed by a line
termination using the carriage return and line feed characters.
For example:
*1234ABCD[CR][LF]. This value is a 32-bit CRC of all bytes in the log, excluding the
'#' identifier and the asterisk preceding the four checksum digits.
See
32-Bit CRC
on
page 43
for the algorithm used to generate the CRC.
5. An ASCII string is one field and is surrounded by double quotation marks.
For example:
“ASCII string”. If separators are surrounded by quotation marks then the string is still one
field and the separator will be ignored (example, “xxx,xxx” is one field). Double
quotation marks within a string are not allowed.
6. If the receiver detects an error parsing an input message, it returns an error response
message. Please see
“Chapter Responses” on page 598
for a list of response messages
from the receiver.
Message Structure:
The ASCII message header structure is described in
Table 3.2
on the next page.
header; data field..., data field..., data field... *xxxxxxxx [CR][LF]