Converting by a switch the HSI compass indicator

[G.Franco 0]

Hi to all,

flying a B742 and using the INS instead the GPS I need to convert the NAV-GPS Switch to NAV-INS.

As in the realty on the B742 the NAV-INS switch changes the HSI compass headings from magnetic to True. That's to follow the INS Great circle navigation.

I made several attempts by the variable tokens:(Plane heading degrees gyro, radians) and the(Plane heading degrees true, radians) but unfortunately with no result.

I've only the magnetic headings or true ones depending on the order that I put the tokens in the gauge.

Any help will be very appreciated.

Thanks Gianfranco

[phjvh 0]

Hi,

 

very old code, but I use:

 

Switch:

(L:href,bool)

 

on the HSI:

%((L:href,bool))

%{if}

%(360 (A:PLANE HEADING DEGREES TRUE,degrees) dnor near d 0 == ?)%!03d!

%{else}

%(360 (A:PLANE HEADING DEGREES MAGNETIC,degrees) dnor near d 0 == ?)%!03d!

%{end}

Hope it helps,

[G.Franco 0]

With your code The HSI compass is stuck indicating North instead of 146.To be sure of the code insertion in the HSI I'm asking if this code is the <Value> of the compass card <Element>.

if it is:

 

 <Element>

<Position  X="198 Y="232"/>

<Rotate>

<Value>%((L:href,bool)) %{if} %(360 (A:PLANE HEADING DEGREES TRUE,degrees) dnor near d 0 == ?)%!03d! %{else} %(360 (A:PLANE HEADING DEGREES MAGNETIC,degrees) dnor near d 0 == ?)%!03d! %{end}</Value>

</Rotate>

<Image Name="HSI_CARD.bmp" ImageSizes="236,236"  Bright="YES">

<Axis X="118",Y="118"/>

</Image>

</Element>

 

Thanks for the help:

Gianfranco

[phjvh 0]

The code i use is just a number in the HSI!

For the rotation try, not tested:

 

<Rotate>

<Value>

(L:href,bool)

if{ (A:PLANE HEADING DEGREES TRUE,degrees) }

els{ (A:PLANE HEADING DEGREES MAGNETIC,degrees) }

</Value>

</Rotate>

[n4gix 4,955]

<Value>%((L:href,bool)) %{if} %(360 (A:PLANE HEADING DEGREES TRUE,degrees) dnor near d 0 == ?)%!03d! %{else} %(360 (A:PLANE HEADING DEGREES MAGNETIC,degrees) dnor near d 0 == ?)%!03d! %{end}</Value> 

That is <Script> format for a <String> statement... You can't do that! Use the precise script Jan supplied.

[G.Franco 0]

Hi Jan,
thanks for your help.I solved the problem and the solution has been so stupid that I'm looking to me as a stupid men.
I used your second code for rotation because the first one, surly because I'm not able to insert it in the HSI,it doesn't work to me.
With your second code everything works properly but  a little correction must be made:You have to add /-/ after the Token Variables.

 <Rotate>
<Value>
(L:href,bool)
if{ (A:PLANE HEADING DEGREES TRUE,degrees) /-/ }
els{ (A:PLANE HEADING DEGREES MAGNETIC,degrees) /-/ }
</Value>
</Rotate>

 

Thanks again for your help
Gianfranco

[n4gix 4,955]

The [/] reverses the direction of rotation.

[G.Franco 0]

Thanks Bill. I have seen the solution in a your previous post I find during a search. Thank you again.

Gianfranco