Weather Control through 0xF1C

[pilotjohn]

Is global weather control through 0xF1C reliable in FSX?

Will it clear existing weather and set the specified global weather?

Does it have to be set "all at once" or can the individual entries be set using individual ipc.writes?

What is 0x0F22, the cloud altitude variation? There's no such GUI option in the FSX weather setup.

I'm thinking of writing a random weather generator Lua script, and would like to know if this offset is useful or not.

Or is 0xC000 the right facility to use with the extended METAR syntax from: http://msdn.microsoft.com/en-us/library/cc526983.aspx#SimConnect_WeatherSetObservation

[Pete Dowson]

Is global weather control through 0xF1C reliable in FSX?

Hmm. Good question. Is any weather reliable in FSX? ;-)

Will it clear existing weather and set the specified global weather?

It tries to. But it's been years since I've known anyone using the FS98-dated global weather offsets, and without poring through the code I can't really say categorically.

Why don't tyou try, possibly via FSInterrogate, and see what happens? If it doesn't look right, let me know with Weather logs (enabled in the Logging options), and i'll work out why.

Does it have to be set "all at once" or can the individual entries be set using individual ipc.writes?

I don't think it matters. Each time you do a change to anything, FSUIPC has to read the weather (which arrives from SmConnect as a strange non-standard METAR string), decode it, change the bit you wrote about, then re-encode it (as an even more non-standard and different METAR string -- yes reads and writes use different formats, dammit!), and send it back.

All that should work, but I can't recall off-hand which weather programs use that old system. The "advanced weather" interface was introduced for FS2002 (I think) then the more widely used New Weather interface in FS2004 (FS9).

What is 0x0F22, the cloud altitude variation? There's no such GUI option in the FSX weather setup.

It isn't used in FSX. In FS9 and before it affects the cloud base -- letting some bits of cloud fall below. FSX does those things automagically.

Regards

Pete

[pilotjohn]

Or is 0xC000 with the extended METAR format the correct facility to use to write weather into FSX?

[Pete Dowson]

Or is 0xC000 with the extended METAR format the correct facility to use to write weather into FSX?

It seems you are misreading something? The Cxxx offsets are all concerned with the NWI (New Weather Interface) and use binary data not METAR strings. The METAR string capabilities are provided through B000-B7FF (writing a METAR) and B800-BFFF (reading a METAR). But for global weather you'd need to use the C8xx section to select global weather mode first. In normal local weather modes setting "GLOB" METAR strings for the global weather only sets the default weather for stations not otherwise set with local weather.

Regards

Pete

[pilotjohn]

It seems you are misreading something? The Cxxx offsets are all concerned with the NWI (New Weather Interface) and use binary data not METAR strings. The METAR string capabilities are provided through B000-B7FF (writing a METAR) and B800-BFFF (reading a METAR). But for global weather you'd need to use the C8xx section to select global weather mode first. In normal local weather modes setting "GLOB" METAR strings for the global weather only sets the default weather for stations not otherwise set with local weather.

Regards

Pete

Ok... is there any documentation on NWI you could point me to?

I couldn't find any, and the only thing I found was the extended METAR syntax. Specifically I'm curious what the syntax of the structure would be to set global mode first, to be able to then write the extended METAR for GLOB.

[Pete Dowson]

Ok... is there any documentation on NWI you could point me to?

In the FSUIPC SDK, the ZIP called "New Weather Interface for FS2004" -- NWI stands for "New Weather Interface", you see?

I couldn't find any, and the only thing I found was the extended METAR syntax.

I don't document that. you must be looking at the FSX SDK, not the FSUIPC one.

Pete

[pilotjohn]

In the FSUIPC SDK, the ZIP called "New Weather Interface for FS2004" -- NWI stands for "New Weather Interface", you see?

Found it... Thanks!