"Pascal" wrote in message
oups.com...
Than You Meindert,

How I can find if the "high speed" of 276C is 38400 or 9600?

There is a way to test the 276C with a file containing records of AIVDM
messages sended by an AIS receiver, and re-sending this messages to
the serial port of the laptop, using a program like Windows
Hyperteminal, so that the 276C woud read them again simulating a real
AIS receiver?

You could indeed try that. This also allows you to test whether the garmin
listens at 9600 or 38400 baud.

Meindert