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tcdang714

Quote:

Originally Posted by

Terry, you're making this sound alot more complicated than it really
is.

The 6-bit encoded part of a VDM sentence is simply a bitstream, packed
using a special code. Each character represents 6 bits of data from
0x00 ot 0x3F. It starts with the message ID (6 bits), repeat (2 bits),
MMSI (30 bits), etc. This is all defined in m.1371 and 61993-2, even if
it is a bit confusing at first.

The first 6 bits being a character and the message ID make it easy to
tell that the example string above is a message 1.

Hi guys,

I'm actually working on a similar project right now except I have to do the ENCODE part of the VDM message. At first I thought every character represents 6-bit but that is not true. As you can see in the message there are lowered case alphabet characters (i.e. 'e') and the ascii value for 'e' is more than 6-bits. I'm a little stuck on my project right now too, can someone give me more info. Perhaps an example in C or C++. Thanks.

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