My question goes to the heart of the low-cost layout software that I would want to purchase (besides its dependability and features!), and that is: Are there any low-cost layout software programs that can both generate and import a PADS or Protel layout file reliably? (Since if I had such software, then when a potential customer asked me which layout package I used, PADS or Protel, I would not have to say "Well, neither! I only have some unknown, low-end software that outputs a format that you can't even read or modify later!"). Or is there, at least, some "standard" intermediate file format that can be transferred between all the various PCB layout packages?
Thanks. Then I guess that means that no matter how good the lower- end (i.e., affordable) PCB layout software is, a professional layout engineer cannot really use anything other than PADS or Protel, since they are the established current standards in the USA. A real shame too, since these high-end packages cost so darn much!
If by "professional layout engineer" you mean someone who's independently doing PCB layout on contract (rather than being a regular employee within a company), you're probably right.
"A real shame too, since these high-end packages cost so darn much!"
Some of the companies will provide a discount for contractors since they realize that the regular prices are a bit much if you're PCB layout isn't the only service you provide. However, it's always the initial purchase price that's a killer -- even the high-end packages usually have maintenance fees that are "only" somewhere in the "mid four-digits." If you're doing contract work and the company expects you to be providing the CAD license, this isn't too huge of a "cost of doing business."
Many low-end packages will export a PADS and, sometimes, Protel netlist (as these are relatively easy features to provide). Importing is a lot harder because importing a netlist without being able to import a footprint library isn't generally useful, and importing footprint libraries is often a difficult feature to provide (i.e., it takes a lot of time... especially with newer CAD programs where pads can be relatively complex shapes).
Not really. Even the big packages can't support all formats reliably.
The only thing close to that is a Gerber file (and netlist), which is what your customer would expect you to provide anyway. But it ranges from easy to ridiculously messy to re-import Gerbers back into any given package. Not to mention the schematic. So gerbers are not really viable as a "transfer" format.
If you are "in the game" then you'll either have to cough up for the big packages, or use a low end package and try to find customers who don't care as much.
Bill, Your shopping list for a low-cost package includes the single feature that nobody offers. The ability to export into a competitive format. The only functions anybody has is the ability to import competitive versions. Their thinking, why would they give you the tools to abandon their software easily? Then as well they are slaves from that point on to the competitiors udates and upgrades whenever and however they come. It is one huge slippery slope for so many reasons. It could be likened to offering a warranty on a competitors product.
Some of these vendors make changes to file formats that are designed to break the importing capability of competitive products. What makes this especially damaging to a design engineer is the fact that some boards still in production may have been created years earlier -- sometimes with a mechanical CAD package.
The long term answer is to switch to an open source electronic CAD system as soon as one that meets your needs is available. The kicker is that each of has unique needs. One person might require nothing less that on of the high end EDA products that cost thousands and thousands of dollars per seat, while another might do fine with a low-end product. If they meet your needs, open-source EDA tools such as Kicad or gEDA will avoid many of the above mentioned problems.
Pulsonix will export schematics in ORCAD format. Well, at least it tries to... there are numerous glitches in the process, but in some cases it's probably still faster than re-drawing the schematic by hand in ORCAD. Pulsonix says they're not really actively developing the feature (i.e., removing bugs), so my suspicion is that someone paid them to add the feature and either is happy with the current performance or else ran out of time/interest/money.
Agreed. Importing data in other format is fraught with difficulties as well... some companies, such as Mentor Graphics, seem to make various minor changes to their netlist formats almost annually for what can either be seen as (1) having a bunch of borderline-competent programmers around or (2) wanting to break everyone's import routines as a means of gaining a "competitive" edge. Interestingly, there's the exact same problem in the mechanical CAD field. AutoCAD, of course, become so much of a standard that there's a funded consortium
that builds libraries to do nothing but read and write DXF/DXG files! The consortium was so successful that Autodesk actually began ENCRYPTING users' designs files (!) (...encryption that was shortly broken by the Open Design Alliance guys), which has got to be about the most customer-unfriendly thing a software company could ever do, in my view.
Although I wouldn't necessarily put it past, say, Microsoft to introduce some new Office that used an undocumented encryption format to prevent, e.g., OpenOffice from reading it and try to pass it off as a security improvement meant to help customers.
...though it's not overtly *encrypted*--it's even more insidious than that: M$ has created a fake "standard"--which isn't fully documented
*-*-*-*-*-competing-*-*-standard+inc+gnu+complaints+Controversially+marketing.contributions+501+*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-chairs+*-*-evaluate-*+application-defined.behaviors+*-*-*-*-*-*-*-*-*-*-ambiguities#Complaints_about_the_national_bodies_process and are buying up support and using other dirty tricks to try to ram it thru ISO approval.
The more interesting question, though, is how much of the lack of documentation is due to Microsoft purposely trying to be evil vs. how much is due to incompetence? I very much agree with Rober Hanlon's saying, "Never ascribe to malice that which is adequately explained by stupidity."
I've been trying to reply for about a week now but had some trouble with the nntp access. I think that is all worked out now--we'll see.
Anyways, as others have mentioned, most CAD packages have a vested interest in locking you into their file format. So not many play well with others with binary file compatibility.
As for intermediate files, a very standard way to do this is with a PADS netlist. Almost every tool supports this in some manner.
If you combine EAGLE with EET :: PADS Interface you can create PADS netlists and ECO files from EAGLE schematic to transfer to external PCB editor or you can import a PADS netlist into EAGLE PCB editor from any external schematic (or other source). I've used it myself to do just that and it works quite well.
Disclaimer: I am a dealer of EAGLE in North America (with online sales, just rolling out right now) and I am the author and dealer of the EAGLE Enterprise Toolkit (EET). So you know my bias. But I'm also an engineer first and I use these tools to do some significant design.