When starting the ACARS client it always register the actual altitude when it is started, which often is negative due to 29.92 standard initial value. The change of the baro during the cockpit checks will not be registered. Does the client only takes the altitude when airborne or is it always aligned to 29.92 ?

It checks for altitude as it checks for all of the other variables it pulls. Ill check and see which FSUIPC variable I am using and report back!

I have used FSUIPC Offset 3324 which says

QuoteThis is the altimeter reading in feet (or metres, if the user is running with the preference for altitudes in metres)

So Id assume it doesn't take the QNH into account?

Chris,

thanks for your reply.

What I mean is that if ACARS is running (still on blocks) and I change my QNH from 29.92 to the actual QNH from the airport, will it not be recognized by the client. So  it is needed to set the correct QNH before starting the client. Seems to be that the client polls the QNH once if it is started and then only if "OFF BLOCKS". Maybe this is due to the special handling of the Dash .

Ermmmm im not sure to be honnest, its probably something to do with the Dash 8! Altitude reporting isnt a huge thing anyway it has no bearing on the operation of ACARS and is only for the position reports and the graph.