B&G Deckman - Manual (Page 171)

Chapter 12: Deckman files
12.12
will reference the NMEA string VHW, using data from field number 5.
You will find that this is boat speed through the water. The third column
shows that this is normal data. The final column shows that this value is
read in to the variable with Deckman identification number 1, which is
boat speed.
For details of NMEA strings and field numbers, please consult the
manual for your instrument system.
[WTP]
This section controls the input of variables from a B&G WTP. The
columns are:
1. WTP function number (from bg_vars.d).
2. Deckman identification number.
For example, the line:
13 6
will read data from WTP function number 13 (which you will find is
heading) into the variable with Deckman identification number 6
(heading).
[instruments]
This section records the settings for connecting to the current
instruments and should not be edited directly.
Reading in a new variable from the
instruments
As was mentioned above, not all variables in the [variables] list
will have data in them by default, so it is necessary to configure the file
as appropriate for your instrument system. By default, the variable
VMG is not read in from any instrument system so we will use this as
an example of what is necessary to read in a new variable. Looking at
the [variables] section in the sample file at the end of this section,
we can see that VMG has Deckman identification number 16.