timsc

Pete, I have started investigating engine parameters around 0x0210 - 0x2314. These seem to have a temporary effect on the engine behaviour. For example if I am stationary with engines at idle and I set with FSUIPC to: *Taxi forward speed 50knots *Engine throttle at full *N1 and N2 at full power the engine N1 gauge jumps from 24->70->61->98 fairly quickly. This means there is not too much loss of thrust in the first 2 seconds of simulation. Setting the engines and throttle to idle does a similar thing (100->40->60->19). I do suspect the gauge reading is a filtered output on the internal N1 value and there is some simulation going on that causes the 70->61 drop in N1. This is not too significant for my application I think. I might have a try with saved files if this fails. Are there any other parameters in SIM1's private data structures that might be relevant that are not accessible in FSUIPC? Thanks for you help, Tim

You obviously know 1000x more than me on the MSFS interface but I would disagree with your interpretation of what a simulator should & could do. What MSFS actually does might be more limited. Allow me to explain. For the engine system at the start of the simulation it has an "initial state". That state could anywhere from stopped to full power. This is independent of the initial throttle setting. The engine system has an input - throttle. (among others) The engine system has an output - N1, N2, thrust force etc. The engine system from moment to moment responds to throttle but it needs to know what state it was in the previous moment for it do to any simulation. It could be thought of mathematically as like engineState(t) = engineState(t-1) + throttleEffect. (I think mathematicians are probably recoiling in horror right now!) The point is I want to set (or reset) the engine "initial state". This is required in any simulation of the engine. Perhaps this is not accessible in the MSFS interface? Regards, Tim

PS I use the words "required thrust" in the broadest possible interpretation. There may be some other writable engine parameter?

Thanks for the quick response. I am setting the throttle controls as you describe. My difficulty is the engines take a few seconds to respond. I need to intialise the engine to the required thrust directly to avoid the engines having to "catch up" with the throttle setting. I hope that makes sense! Tim

Pete, or anyone who knows, I am working on a tool to set a aircraft to a preset location, attitude and other settings for use in pilot trials. One parameter that is proving tricky is the engine status. This is necessary as after I set the aircraft in flight using FSUIPC, the airspeed falls very quickly as the engines take a few seconds to respond to the throttle input. This causes the nose to pitch down rather alarmingly when starting the trial. I am writing the engine N1 to locations 0x0898, 0x0930 etc. The engines do not seem to respond. I expected a spike in engine N1 lasting for a few seconds (until they respond to the throttle). Are the N1, N2 values output parameters only? Any alternate method for setting engine thrust? Or has anyone attempted to make a preset locations tool for MSFS? short int test = 16876; //About 102% N1 Sim.Write(0x0898, 2, &test); Sim.Write(0x0930, 2, &test); Sim.Write(0x09C8, 2, &test); Sim.Write(0x0A60, 2, &test); Sim.Process(); Regards, Tim

I think I cracked it (with a little help from you!). I was looking through the documentation for the memory areas you mentioned (3060-30B8 and 3178-31D0) and spotted 3090 which is exactly what I want! So it is possible to initialise the aircraft's speed, or to be exact its forward velocity. Thanks, Tim

Pete, Thanks for your response. I am now specifically looking at a stationary aircraft on a runway. I perform the following actions to set the altitude and throttle to full power. After this the aircraft falls out of the sky! The aircraft initially has zero speed. The throttle value does not seem to have any initial effect athough they eventually increase the aircrafts speed (adding to the effect of the aircraft accelerating downwards). Does the aircraft speed have to be considered an "effect" variable? I find this counter intuative as a change in latitude/longitude is caused by speed. Speed is a cause in this example. Also we can change the affected variable (latitude/longitude). Any ideas? Would it be possible to introduce speed as a writeable variable? The FS2004 map I mentioned is the built in standard map accessed by menu - world - map. This allows entry of a position, heading and airspeed. This is the behaviour I am trying to achieve with FSUIPC. Thanks, Tim

Pete and everyone, I am attempting to set the initial position of my aircraft using FSUIPC. I read that the airspeed cannot be directly controlled (along with vertical speed as far as I can tell). Is it possible to control the thrust or throttleusing FSUIPC to get the aircraft's airspeed set? I can do this using the FS2004 map but not using the programmer's interface. Thanks, Tim