jd

do it the math this way x / 65536 / 65536 * 360

you have to do some conversions here is my routine to set the plane at the proper lat/long/alt Public Function set_plane(lat As Single, lon As Single, alt As Single, hdg As Single) As Boolean Dim x As Long Dim dwresult As Long x = FTOM(CLng(alt)) Call FSUIPC_Write(&H574, 4, VarPtr(x), dwresult) x = lat * 10001750 / 90 Call FSUIPC_Write(&H564, 4, VarPtr(x), dwresult) x = lon * 65536 * 65536 / 360 Call FSUIPC_Write(&H56C, 4, VarPtr(x), dwresult) x = hdg * 65536 * 65536 / 360 Call FSUIPC_Write(&H580, 4, VarPtr(x), dwresult) Call FSUIPC_Process(dwresult)

Call FSUIPC_WriteS(&H8001&, Len(fsuipckey), fsuipckey, dwResult) ' Call FSUIPC_Process(dwResult) where fsuipckey is a string containing the key (no spaces), concatenated with a null jd

for the ai aircraft, that data is in the tcas tables. check the documentation for specifics jd

my vb does unsigned arithmetic :-)

you're probably overflowing the magvar variable i use MagVar = MagVar / 65536 * 360 what is the real magnetic variation where you're at? i'm betting that it is really -20, which will yield a number slightly higher than 360 so you will need a routine to take a heading that is larger than 360, and normalize it to a number between 0 and 359 jd

no idea, sorry jd

Function norm360(h As Long) As Long If h > 360 Then norm360 = h - 360 ElseIf h = 0 Then norm360 = 360 ElseIf h < 0 Then norm360 = h + 360 Else norm360 = h End If End Function

here is my code snippet Public Function Plane_heading() As Single ' degrees Plane's magnetic heading. Dim x As Long Dim dwResult As Long Call FSUIPC_Read(&H580, 4, VarPtr(x), dwResult) Call FSUIPC_Process(dwResult) Plane_heading = norm360((x / 65536 / 65536 * 360) - magvar) end function you may have to adjust for the magnetic variation, which is what magvar is (another function, to get the current magnetic variation) norm360 is a normalize function, which brings all heading to a range of 1-360 degrees

twenty degree magnetic variation would put you within 1 degree of the number you gave me jd

and what was the magnetic variation? jd

what was your plane heading?

i don't know what to say. this is the function i have used in radar contact since v3. it works, because i'm constantly checking the plane heading.. Public Function Plane_heading() As Single Dim x As Long Dim dwResult As Long Call FSUIPC_Read(&H580, 4, VarPtr(x), dwResult) Call FSUIPC_Process(dwResult) Plane_heading = x / 65536 / 65536 * 360 End Function

it's vb6, and the code has worked that way from v3.x through v4.x without a problem.

Public Function Plane_heading() As Single Dim x As Long Dim dwResult As Long Call FSUIPC_Read(&H580, 4, VarPtr(x), dwResult) Call FSUIPC_Process(dwResult) Plane_heading = x / 65536 / 65536 * 360 End Function