"Wout B" wrote in message
...

For this test, you want to connect the Transmit line of the PC Com port to
NMEA IN. Connect your PC Com port pins 3 and 5 to NMEA IN + and NMEA IN -
and transmit a $SDDBT sentence from Hyperterminal to the ST60 Multi
instrument.
Start Windows program Notebook and type the following NMEA sentence:
$SDDBT,-2.0,f,,,,*22 Press Enter and save this text in a file. The
value -2.0 represents a "negative" depth of 2.0 feet.
Start Hyperterminal with the PC connected to the ST60 instrument as
described above. Click on Transfer at the top of the Hyperterminal screen
and select "Send Text File". Find the .txt file you saved with Notebook
and
transmit.

Why can't you just type the sentence directly in Hyperterminal?

Meindert