L.S.,
I am driving from/to FS2004 via FSUIPC an (external to MS FS) Heading Indicator instrument with a Gyrodrift Compensation knob.
FSUIPC is version 3.201 of 16 Febr. 2004.
My software reads 3 values via FSUIPC: True Heading in $0580,4 Magnetic Variation in $02A0,2 and Gyrodrift in $0C3E,2.
It calculates 'Indicated Heading'
(Indic.Hdg = True Heading + Gyrodrift - Magnetic Variation) and sends this regularly to the instrument; this goes fine.
I encounter difficulties when the user turns the Gyrodrift Compensation knob on the instrument and i want to send the altered value to FS via FSUIPC.
I observe the following:
- the start situation is: Gyrodrift=0 degr, Magnetic Variation=-3.0 degr and True Heading=231 degr; the Indicated course is 234 degr, all ok,
- my s/w reads the given Gyrodrift Compensation value from the instrument, lets say 0.5 degree, converted to FS 16 bit smallint this gives 81,
- my s/w writes via fsuipc this value of 81 in $0C3E,2
- the next time that my s/w reads the 3 values, the Gyrodrift repeats my value of 81,
- the problem is that the next time thereafter (16 ms later) my s/w reads a Gyrodrift of 0, so 'something' has overwritten my input.
Only when I increase the given value over 192 (is > 1 degr) a non-zero value is read back in the 2nd cycle, but it is still lower than the given value.
I have tried the same by:
- setting the FS in slew-mode, then update the value, then set back to normal mode, but the same effect,
- setting FS drift-simulation OFF, but the same effect.
- I have not tried this with a newer version of FS.
My questions are:
- Do you know about this 'problem'?
- Is this solved in newer versions of FS?
- Is there another way to in/de-crease the Gyrodrift value in FS?
- Is there any other way that you can help me?
Thanks in advance and Regards,
Adrie