Hi All,I cannot seem to get the penny to drop. Can someone provide me with a simple code example using L vars to turn on and off the nav lights.I can get it to work using normal code but I'm trying to get a grip on L vars and it would help, I think, if I can compare the two side by side.Here is the normal code thats works. Can L Vars do the same?(A:Light nav,bool)Yes I have read many discussions on this topic but it still eludes me.Thanks,Douglas.

Of course not...L:vars are custom defined variables that aren't tied to anything specific in the sim.Besides, L:vars share one property with A:vars - they simply report a condition. They are not "action variables" (or "verbs") at all.Only K:variables are "action variables" - or, more properly are "key events." That is, they control stuff.Using your example, TOGGLE_NAV_LIGHTS (or (>K:TOGGLE_NAV_LIGHTS) ) is an "action event" - that is, it controls whether NAV LIGHTS are on or off.(A:Light nav,bool) on the other hand, is an "adjective word," that is, it reports the condition of the NAV LIGHTS as 0 = off or 1 = on.The primary use of a custom, L:variable would be to keep track of something that is not already provided for by the default A:variables.

At least for L Vars, this may be helpful:"Anatomy of an XML code"http://www.aerodynamika.com/cgi-bin/yabb/Y...;num=1129865563by Fr. Bill.BTW Fr. Bill - thanks for this post. It puts in perspective how to "think" about the different variables.

Gentlemen,Thank you both for the replys and explanations and link.I guess I cannot see the forest for the trees but I'll get it yet having had some success with this gauge.Thanks again,Douglas(L:GEN1 Switch,enum)(L:GEN1 Switch,bool) 0 == //// AC Volts %((A:electrical genalt1 voltage, volts))%!3d!APU GENGEN1(ON):3 (>L:GEN1 Switch,enum)