As nobody has responded to a previous message which I sent to this mailing list (almost a week ago), I am currently inferring that there is almost certainly *still* an outstanding issue concerning how pads with an Octagonal shape are depicted within Gerber files.
Had that issue actually been rectified by now, I would have expected that at least one other member of this mailing list would have pointed that out before now (and perhaps with some glee at the time). I don't know whether other users are avoiding the use of such pads (having an octagonal shape) because they are aware that there are (or at least have been) issues with such pads, or whether they genuinely have no requirement to ever use such pads; for all that though, the way that such pads are depicted is still a "gotcha" for any user who is not fully "up to speed" on that matter (unless of course that issue actually has been rectified by now). And it is not as though Altium can claim that it is not possible to correctly depict such pads within Gerber files, as *any* pad with an Octagonal shape property can be properly depicted within Gerber files. And if "Outline" type "Aperture Macros" were *always* used (and *never* Polygonal Aperture Definitions instead, including even when using them would in fact be possible), the matter concerning how Polygonal Aperture Definitions should be interpreted would also be avoided. Assuming that there really still is an issue concerning how such pads are depicted within Gerber files, perhaps other members of this mailing list have been reluctant to publicly confirm that because they suspect that actually doing so could result in them falling out of Altium's favour. So if anyone is prepared to correspond with me in private on this matter, I solemnly give my word, here and now, that I will not subsequently publicly identify anyone who actually does so. And if this matter really still hasn't been rectified, it can only be described as a scandalous disgrace. Altium is well aware that there is an issue in this regard, they have also been aware of that issue for many many years, and they are also aware (and have been for at least a year) of what can and should be done to fully rectify it. It would still be appropriate to mention at this point though that it would be highly advisable, and arguably even necessary, to make four other changes at the same time (as rectifying this issue). First off (if not already implemented), all Gerber files should incorporate a comment which identifies the version of the application which was used to create those files. (If it is not obvious as to *why* that should be done, read on...) Secondly, the source code associated with *importing* Gerber files *directly* into *PCB* files should be updated so that "Outline" type "Aperture Macros" which depict octagonal shapes are correctly interpreted. (Amongst other requirements, that software should determine that the nine pairs of coordinates provided within each "Outline" type "Aperture Macro" of such a nature are *all* consistent with the vertices of a pad having an octagonal shape, with one of the associated requirements being that the location of the ninth coordinate pair listed should exactly match the location of the first coordinate pair listed. And furthermore, that analysis should be done regardless of whether or not each Gerber file also incorporates "CAMtastic-friendly" comments for the purpose of describing the properties of such apertures; if in fact such comments actually were provided, they would then facilitate the task of fully parsing the contents of each "Outline" type "Aperture Macro" (as the details within each such comment would effectively specify what to expect within the corresponding "Aperture Macro").) Thirdly, to cater for Gerber files which were created by earlier versions (prior to this issue being rectified), the same source code (for importing Gerber files directly into PCB files) should also parse the comments within the Gerber files to determine whether those Gerber files were created by an earlier version of the application, so that it can subsequently be determined whether any of the embedded aperture definitions contained within those files could be "suspect". (Note of course that the *absence* of any such comments would imply that there could be "suspect" embedded aperture definitions within the Gerber file concerned - and hence the reason for identifying the version of the application used to generate the Gerber files from now on.) And in the event that any "suspect" embedded aperture definitions are in fact detected, then the user should be notified of that fact (by a dialog box), and "polled" (within the same dialog box) as to whether those embedded aperture definitions should then be interpreted in the same way that they had *previously* been interpreted (while using earlier versions of the application). And fourthly, the source code for importing Gerber files into *CAMtastic* files should also be updated so that it similarly determines whether any "suspect" embedded aperture definitions contained within a Gerber file could have been created by an earlier version of the application. (And it would also be important to similarly "poll" the user as to how such aperture definitions should be interpreted, as the Gerber file(s) concerned *could* have been created by a *different* application which has not had the same issues concerning pads with an octagonal shape.) I am not claiming to be omniscient, so if anyone can think of any *other* changes which should *also* be made at the same time, then they should "sing out", and ASAP (and if they consider it appropriate, within a private message sent just to me). On their form to date, it would be very unwise to assume that Altium's management would be capable of figuring out for themselves as to whether any other changes would also be required, as there has been a regrettably large number of occasions when new features have been provided which have not been fully thought through, and which have subsequently made many users' experience in using AD far more disagreeable and frustrating than what it really should be. Regards, Geoff Harland. [EMAIL PROTECTED] ----- Original Message ----- From: "Geoff Harland" <[EMAIL PROTECTED]> To: "Protel EDA Discussion List" <[email protected]> Sent: Tuesday, November 21, 2006 4:16 PM Subject: Octagonal Pads (was Re: moving to ad6) <snip> > However something else which I am not yet certain about involves pads > which have an octagonal shape. Within the release notes which were > provided for SP3 (for AD6) is the following item: > > "Rotated octagonal pads are now exported correctly to Gerber." > > *If* the wording of that item had, instead, actually been something like > this: > > "Octagonal pads are now always exported correctly to Gerber." > > then that would have suggested that such pads are in fact correctly > depicted within Gerber files, *BUT* ... > > my experience, with *all* versions of Protel/AD up until SP4 for AD 2004 > (the last SP released for that version), is that pads which have an > Octagonal Shape property have *NEVER* been depicted properly within Gerber > files, and that is the case regardless of the relative values of their > X-Size and Y-Size properties (equal or otherwise), and regardless of the > values of their Rotation properties (zero degrees or otherwise). <snip> > As I mentioned before, you could create ODB++ files from a PCB file, then > export Gerber files from the CAMtastic file depicting the ODB++ files, but > doing that definitely requires distinctly more work. And it shouldn't be > necessary to have to jump through those additional hoops, so whenever > users were to opt for the more direct (and logical) option of generating > Gerber files *directly*, then the contents of those Gerber files *should* > *always* be fully "kosher"... > > Regards, > Geoff Harland. <snip> ____________________________________________________________ You are subscribed to the PEDA discussion forum To Post messages: mailto:[email protected] Unsubscribe and Other Options: http://techservinc.com/mailman/listinfo/peda_techservinc.com Browse or Search Old Archives (2001-2004): http://www.mail-archive.com/[email protected] Browse or Search Current Archives (2004-Current): http://www.mail-archive.com/[email protected]
