Novatel OM-20000041 用户手册
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Command Descriptions
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MiLLennium GPSCard Software Version 4.50 Command Descriptions Manual Rev 1
NOTE:
All previously stored configurations that were saved to non-volatile memory are erased (including
Saved Config, Saved Almanac, and Channel Config).
Example:
Optional calculation of the checksum
When an input command is followed by an optional checksum, the checksum will be verified before the command
is executed. The checksum is the result of the logical exclusive-OR operation on all the bits in the message. So,
the checksum of a command with parameters will change if the parameters are modified.
is executed. The checksum is the result of the logical exclusive-OR operation on all the bits in the message. So,
the checksum of a command with parameters will change if the parameters are modified.
NOTE:
The command must be typed in uppercase for the proper checksum to be calculated.
As an example, it may be essential to ensure that a receiver has received and executed the correct command from
a host computer. If the checksum were calculated by the sender and attached to the command, the receiver would
be able to recognize if errors had been introduced and if so, alert the sender to this with an “Invalid Command
CRC” message.
a host computer. If the checksum were calculated by the sender and attached to the command, the receiver would
be able to recognize if errors had been introduced and if so, alert the sender to this with an “Invalid Command
CRC” message.
Example:
FIX HEIGHT 4.567[CR][LF]
FIX HEIGHT 4.567*66[CR][LF]
FIX HEIGHT 4.567*66[CR][LF]
Both are acceptable, but only the second one would trigger the verification function.