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Guest BigJacko

PSS AB Pro - what ARINC-424 trackcodes can it use?

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Hi again Terry,I asked this question on the PSS Forum, and Rob Elliot suggested that you might be the best person to ask.Any ideas? I seem to be having difficulties getting the PSS 'bus to respond to CR, CI, VR & VI trackcodes correctly (CR & CR just get ignored completely and the plane files off on a heading until doomsday, while CI & VI just seem to cause a far-too-early 30-degree intercept to be set up for the following waypoint in the next leg, and that isn't accurate enough to avoid traffic-conflicts on some procs).Unfortunately, as some friends of mine who use the payware service are discovering, the latest Navigraph procs seem to make heavy use of these 'dodgy' ARINC trackcodes, and (because they know I'm a geek who relishes this kind of stuff), their cries of help have come to me!I have tried many hours-worth of 'suck-it-and-see' to work out what the PSS bus can do, but I'm not making great headway. Do you know if there are any reference materials which document what the PSS Bus can and cannot do, from the ARINC set?Many thanks in advance for any help.

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Hi Neil,>Any ideas? I seem to be having difficulties getting the PSS 'bus>to respond to CR, CI, VR & VI trackcodes correctly I was told by PSS years ago that all the track codes are OK to use but we know that at least the PI and AF are not because the planes do not implement the procedure turn and the ARC. So all we can do is string all those leg types together and hope they execute properly. This does presume that all the required data for each track code is provided in the procedures. Where they fail to produce the desired course we have to improvise with other codes where possible. There are a few restriction in the AIRAC codes that I've discovered though but I don't know if they are implemented in the FMC code. For example a PI must be followed by a CF and a CI needs to be followed by a CI or a CF. BTW you use the VI code. I have not found that to be used at all so far in the DAFIF or the USFIF data. Not sure what that means, it's just an observation.As for how they actually execute that would have to be something you would have to take up with the PSS programmer that does the FMC code. I don't know who that is though.Sorry I can't help more.RegardsTerry

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Hi Terry - thanks for that. We share the same pain, it seems ;)I'm reminded of the definition of Loop, in the coder's dictionary... It simply said 'See Loop' ;) :DI've just had a conversation with Rob at PPS, and he's explained that the original coder was Prabhal Ghosh - and he's left the FS community several years ago, and taken all the knowledge with him. Basically, nobody at PSS knows what the FMC can and can't handle from the ARINC424. Oops! :DFor ref, the VI and VR is simply 'vector to intercept' and 'vector to radial' - essentially the same as CR and CI, but referencing a radar-heading (without wind correction) rather than a track or course.There's also a corresponding VA (vector to altitude) which is similar to the CA - and again, another one of those 'undefined endpoint' commands, with all the encumbent problems in some sim FMCs.Alas, however, in my experiments with the PSS over the last few weeks, it appears NONE of the CR/VR commands work at all. The plane will simply fly the heading until doomsday, no matter what the next leg-line is.And with the CI/VI commands, even if there is a proper CF/VF leg next, PSS planes will IMMEDIATELY upon passing the CI point, turn to a heading that is plus-or-minus 30 degrees to the radial which is to be followed, once intercepted. Of course, if the preceding part of that command (the vector/course to the radial itself) is a long one, this 30-degree-to-radial heading can cut corners massively, and bring you right across an approach, for example! Like you, I usually get around it by judicious use of CF and simple TF commands (and indeed, the current 'gospel' from EuroControl indicates that ALL commands based on the use of navaids are ultimately to be phased out, and TF and IF will be practically the only commands in use in the future... but that requires us to have access to all those 'indistinct waypoint' latitudes and longitudes, which is going to mean a long summer's job for me, and you too, I expect! :) I can see EuroControl's logic... they want all RNAV FMC code to be entirely independent of navaids which might be turned off, or go fritzy - and instead, they want everything based on inertial lat-lon guidance. Figures... but the changeover will be a long hard road for us out here in sim-land, without access to DAFIF and its ilk!Worse - Navigraph are using many of thse codes still, because their data is sourced from 'real world' implementations. I know that doesn't affect your stuff, but yours has another wrinkle (see other topic) which may need ironing out.As said before, I'm more than willing to assist with any testing of your stuff, if you ever think you might need a body that understands the UK differences, and has a bit of coding skill. It's the least I could do after all your hard work for us all.Regards, and thanks againThanks

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