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n4gix

xml tachometer-with elapsed time

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I've made a tach in xml, but I don't know how to get the hours to show. I've searched the net and found how to get the time to save, but I doubt that puts the numbers in for me...I'm guessing there's more to it. BTW, from time to time I post pics of my project in the screenshots forum-search for "thorp"Robert

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It looks like I need to have a vertical band of digits (0-9) and a mask image to limit them to the window on the gauge. I have those bitmaps done, but I'm having trouble understanding how to position each band (100's, 10's, 1',etc) and how to get each one to "slide".Can anyone enlighten me?Robert

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Well, I think I have figured out how to position the mask and bands, but getting them to move still eludes me.The Tutorials at fs2x.com and the freeflight design shop are quite helpful if you're new to this xml stuff like me...Robert

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>I've made a tach in xml, but I don't know how to get the>hours to show. I've searched the net and found how to get the>time to save, but I doubt that puts the numbers in for>me...I'm guessing there's more to it. >Robert While one can save L:Variables to a log file with one of Doug Dowson's interface gauges, I don't know of any way to read a file that would contain the Tach Time at the end of each flight. The standard Tach with total hours saves the 'end of flight' Tach time to a file in a subfolder of the USER folder. Ron

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There is a hobbs meter in Milton Shupe's Beech 18. Maybe that would serve as a guide.

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I think the engine time is saved in: C:Documents and SettingsUserApplication DataMicrosoftFS9AIRCRAFTin the state.cfg file for every aircraft regardless of whether it's been flown. I have at least one aircraft with zero engine hours in that folder.Also, it doesn't seem to depend on the tacho, nor does the tacho seem to need any special coding to achieve this. Check the Spirit of St Louis tacho XML.EDITThere is a varible GENERAL ENG ELAPSED TIME in Parameters.doc in the SDK that might be what you're looking for. Engine parameters take an index (1,2,

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I checked the items recommended above, but no luck. One thing I came across last night was this...%((A:GENERAL ENG ELAPSED TIME:1, seconds) 3600 / d 1 % 60 * r flr )%E1 %!05.0f!:%!02.0f!So I went back to 'school' and learned that strings are used in conjunction with text lines. After some reading, trial, and error I now have a digital readout of elapsed time on my tach.I sat in my plane with the engine idling, and noted that my timer is slow...'bout 3.5 minutes to get 1 hundredth on the 'clock'. Should take 36 seconds-time to learn xml math...At this point I think it's a matter of using this parameter with the math modified to shift each band bmp the required amount (more school to get that part figured out). At least I have SOMETHING on the tach!http://forums.avsim.net/user_files/135263.jpgRobert

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To figure out if my slow clock was due to a math error or a timing error in the sim I modified the code to display the run time in seconds.5 seconds real-time=1 second on the display. No math involved in the code. I used (A:General eng elapsed time:1,seconds). The display also is correct to the stored value on the hard drive.Any idea where/how in the sim this is generated, and can it be fixed?Robert

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If I multiply the A: value by 4.7 I get a pretty accurate count in seconds, but only at idle (600 RPM). Increasing RPM also speeds up the count rate.I also placed a stock Cessna 172 Tach on the panel. It's way slow at idle too, and appears to also be affected by RPM.At high RPM the Cessna tach is pretty accurate.The Elapsed Time parameter should not be affected by RPM.Is this a known problem? I've been looking around the 'net, but find nothing.Robert

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>If I multiply the A: value by 4.7 I get a pretty accurate>count in seconds, but only at idle (600 RPM). Increasing RPM>also speeds up the count rate.>>I also placed a stock Cessna 172 Tach on the panel. It's way>slow at idle too, and appears to also be affected by RPM.>>At high RPM the Cessna tach is pretty accurate.>The Elapsed Time parameter should not be affected by RPM.>Robert "Tach Time" assumes a typical cruise engine RPM, so it runs slow at idle. A 'Hobbs Meter' accounts for real time. It's generally nicer to pay for AC based on Tach, rather than Hobbs Time. Since warmup and taxi doesn't increase the reading much. Further, Tach Time is used to figure when the engine is due for an overhaul. If you need real time, maybe you could divide the A: value by "RPM/constant". Where the constant is probably around 2500 RPM, perhaps corresponding to 75% HP at low altitudes. Ron

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It might be helpful to keep in mind that the time stored for the HOBBS is actually HOURS:TENTHS-OF-HOURSIOW, every six minutes the "decimal portion" is updated. :)

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>There is a hobbs meter in Milton Shupe's Beech 18. Maybe that>would serve as a guide.Hello,I have some difficulties to find this xml gauge in this plane...:-hmmm What is the name?TksG

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About Your (and all other tach meters - in the sim or in RL) being slow at idle: It is CORRECT behavior, since thach meter is a pure mechanical "clock"device and is actualy converting the revolutions of the engine brought to the RPM indicator by means of a stiff transmission. The revolutions of the engine are then directly displayed with the pointer, engine elapsed time is generatedby a "gearbox" and is engine RPM dependent. Philosophy behind this is to somehow get the "engine stress" time and in this philosophy considers an idling engine is at almost no stress. Furthermore, at full power the tach time is "faster" than the real time clock, since tach time equals the real time only at 75% of the max rpm. Since aircraft engines have a TBO - time between overhaul this measuring system is a fair solution, since when at low RPM, the engine is not at stress and the "engine time" is consumed at a slower rate and the other way 'round - at above average 75% power the engine time is consumed faster than the real time.So check Your tach agains the clock at 75% of the max RPM and I bet it'll bequite close to the clock elapsed time.

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