On 3/4/2012 9:52 AM, Dan McMahill wrote: > On 3/2/2012 4:22 PM, rickman wrote: >> Hi Julian, >> >> Thanks for the help. I am attaching the drill file here. The issue >> seems to be that in spite of the fact that there are Execellon commands >> to specify the drill sizes some software puts them in comments in a >> header or I've even seen web pages saying the tool descriptions should >> be in a separate file! So I expect the problem really is the source >> software that created this file which I have no control over. > Welcome to the world of drill files :( The way gerbv tries to deal with > this mess is it tries its best to actually follow the Excellon rules. > When that fails, and it will from time to time due to essentially broken > software generating the files, you can manually tell gerbv what format > to use for the drill file. Right click the drill layer in the layer > list on the left of the gerbv window. You can tell gerbv what format (# > of decimal, leading/trailing/no zero suppression, etc.).
I had seen that, but it doesn't fix my problem of the drill files not having proper tool size spec. Still, given all the issues I am pretty happy with they way Gerbv works. It seems to work a lot better under Windows now and I see the zoom range is better than that last time I used it. It used to be hard to get an accurate measurement of fine details but now the zoom goes in much further. >> On a similar note when I dug for specs on routing files I came up empty >> handed. It seems they are much less standardized although Excellon >> covers that in the drill codes if you stick with that. > I've had limited dealings with route but in the past what I've seen was > the routes were drawn as though the were copper and exported as gerbers > and the fab house was then told "oh, this is a route". > >> How does the >> industry ever cope with this stuff? > With drill files, some fab houses ask you to tell them what format. A > number of them ask for a drill tool list and they'll tell their tools > the right format to make it work out in the face of broken EDA software. > They deal with enough different sources that they've seen it all and it > doesn't take them much time to look at a drill file as it loads and say, > "oh, clearly this needs to be interpreted in format Z to make sense". Yes, but it is still work to do the conversion or whatever they need to do. When someone sends me a PDF file I don't have to determine what size paper is was intended for or whether it is portrait or landscape, etc. I just open it in Acrobat or Sumatra or whatever I use for viewing PDF files. As an engineer it pains me whenever I see inefficiency especially when it impacts schedules or results. I now know that a drill file should properly contain the tool sizes. But on the other hand as Steve pointed out neither the conventional Excellon drill files nor any of the routing file formats are truly appropriate for conveying drill or routing data unless it is intended for a particular machine. In reality there should either be a single standard for all machines (which ain't gonna happen) or some appropriate, independent standard should be devised. The Excellon format seems to be a defacto standard for drills, but none seems to exist for routing. The routing I have seen on PCBs appear simple enough to be conveyed by a Gerber file. The other way I suppose we have all seen done is to use a Gerber file as a fab drawing with the drills and routes including the tool descriptions as well as other information about the design. I never understood why this is done until today. But that doesn't convey so well to a program like Gerbv. Actually the way FreePCB does it, the drill information in the fab drawing overlays the rest of the Gerber files and all is well. > Your routing file looks like a G-code file. I do not have direct > experience working with those. I'm guessing it wouldn't be that bad to > teach gerbv to load and render those. I also suspect for routes that > makes sense. > > For pick and place files (x,y rotation, side) I was totally unable to > find any sort of standard at all. I wrote the xyrs exporter for pcb and > when trying to find "the" format it seemed that there really wasn't one. > I took the approach then of making up one that can easily be parsed by > excel or awk or perl and then carefully documenting the format. > > -Dan Yes, that is what I have found. I now realize why. None of the many different file formats used for controlling routers are appropriate for a universal standard for describing the holes to be made. The XYRS fiasco is only mitigated by the IPC standard defining the convention for rotational and positional orientation. But that does not include a file format unfortunately. Where would I find documentation on your format? FreePCB has a companion program for generating XYRS files which is somewhat programmable. I might be able to adapt it to your format. At least then there would be two people using the same standard... ;^) I have looked at the IPC site and found a number of "standards" which no one pays any attention to. It would seem the PCB fabrication industry has little interest in improving their lot. In their defense I read a web site that explained why, after more than one attempt had been made to define a new standard for PCB etching patterns which could include all of the other information important for making PCBs, the industry sticks with Gerber files. Basically it comes down to the fact that many of the errors in Gerber files are errors in usage (which is not an adequate reason in my opinion) and that the learning curve would not be without its own errors resulting in significant short term costs. In many ways the current system is the "devil we know". Rick PS Are you aware of the PDF document for XYRS files published by Screaming Circuits? http://blog.screamingcircuits.com/2009/12/a-few-hints-of-the-centroid-file.html ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. 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