The code below works fine. However, I need to add one condition and do not yet understand xml logic well enough to get it to work. (A:AIRCRAFT WIND X, knot) (A:AIRSPEED TRUE, knot) / 60 * int I do not want the needle to rotate when the plane is on the ground; instead, I want it to face North. I know (A:SIM ON GROUND, bool) is probably the variable needed, but have not succeeded in getting that to give the effect desired.Something like this: if (A:SIM ON GROUND, bool) is 1, then Item Value = 0 (which rotates needle straight up).Any assistance appreciated,Glenn

Easy one:) (A:SIM ON GROUND, bool) ! if{ (A:AIRCRAFT WIND X, knot) (A:AIRSPEED TRUE, knot) / 60 * int } els{ 0 } --Jon

Jon,Is this the logic of your code:If (A:SIM ON GROUND, bool) equals 0 (false, not on ground), then do the calculations inside the "if" statement. Else produce a value of 0. I'm having a bit of a problem getting a handle on RPN and space requirements of xml.Thanks for the reply.Glenn

That is exactly what Jon is saying !Steve