This command gets a double float from
the specified packet. Typically double floats are 8 bytes in size and
ranges from -1.7E308 to +1.7E308 with 14 to 15 digit accuracy.
The data will be taken starting at the cursor position and the cursor will be moved forward by the size of the data returned.
long long int Packet: This is the packet that the command should use.
Data from the specified packet if no
error occurred.
0 if an error occurred.
DBP