Re: [PEDA] Printed Gerber, Shape of SMDpad and silk circle
A note on the etiology of the Protel Octagonal pad mess: The original Gerber specification for octagonal pads was somewhat ambiguous. It appears that the Protel programmers didn't realize the ambiguity and nail it down, an easy mistake to make. Anyway, when the specification was rewritten to remove the ambiguity, it was not the way Protel had interpreted it. The ambiguity was the definition of zero rotation for a polygon: Is it point up or flat up? As I recall, I'm not looking at the spec, zero rotation is defined point up (or down, I don't recall). The result is that Protel octagons are 22.5 degrees off. The Gerber specification is counter-intuitive for anyone accustomed to working with pads! * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[EMAIL PROTECTED] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] double pins
At 04:46 PM 12/5/2003, Rene Tschaggelar wrote: A footprint of a connector, the microstac of ERNI, contains each two faces per pin. Each pin is just one piece of brass, but not touching in its middle. An explicitely not having copper there. So I placed two pins with the same number each. Protel 99SE somehow doesn't like it. From the netlist, only one of the two is assigned a net, the other is left out. I wasn't certain that I understood the question, so I didn't respond yesterday. But now, I think there is a comment to be made. I'm still not certain I understand what is on the PCB. Perhaps it is a dual-row connector, either male or female. In the former case, there would be PCB fingers on each side of the board. This mates to spring contacts; logically, there is only one single row of pins; however, physically, on the board, there are two rows (perhaps on the top and bottom if it is male, or perhaps two rows of holes for two connector pins, same basic situation). This then reduces to the old question of how Protel treats pads with the same name. If you start with a fresh board, no netlist loaded, and you place the parts, then load the net list using Netlist load, the last behavior I saw was this: Both pads would be assigned the net. Then, next time you loaded the netlist, macros were created that would remove the net from both pins. If in some way you start with one pad with the name and the other without it, loading the net list would reverse the assignments. To my knowledge, this was never fixed in 99SE. (The behavior was improved with a 99SE service pack, but they didn't quite get it right.) The Synchronizer, however (i.e., Update PCB from Schematic), behaves correctly. I.e., all pads with the same name (i.e., REFDES-PADNAME) are assigned the same net. This is useful in lots of situations, but you do have to be aware of the bug. It is a good idea to reload the net list or resynchronize before being certain that a design is done. If there are any macros created, take care to see that they are harmless. Multiple pads with the same name are something to look out for If you use netlist load, as you must when, for example, working from an OrCAD schematic, all the macros should be for removing the correct net assignment. You simply don't, then, allow the macros to execute. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[EMAIL PROTECTED] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] double pins
This then reduces to the old question of how Protel treats pads with the same name. If you start with a fresh board, no netlist loaded, and you place the parts, then load the net list using Netlist load, the last behavior I saw was this: IMO, the way to treat the double-pin scenario is to assign each of the 2 pins a unique name (or number). This has been advocated before by others on this list. Imagine if you were the Protel computer program. The user would need to tell you in an unambiguous manner how these double pins were instantiated. If they are given the same name, how can you tell them apart? The only way is if you, the program, assigns every object a unique object identifier, which is known only internally to you, and not to the user. Does Protel do this? We don't know, and since we don't have the source code, we cannot find out. Therefore, we must use our own unique identifier. In Protel, the tools available to us to do this are pin names and numbers. So, we should assign a unique identifier to each pin in the pin pair. As to the old question of how Protel treats pads with the same name/number: we don't know for sure, and cannot find out. And anything we assume is likely to become incorrect across versions. So it's best to use unique pin names/numbers. Best regards, Ivan Baggett Bagotronix Inc. website: www.bagotronix.com - Original Message - From: Abd ul-Rahman Lomax [EMAIL PROTECTED] To: Protel EDA Forum [EMAIL PROTECTED] Sent: Monday, December 08, 2003 7:45 PM Subject: Re: [PEDA] double pins * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[EMAIL PROTECTED] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
[PEDA] Protel99 to Orcad DSN?
Anyone know if there's a way to convert protel99 schematics to Orcad DSN format? Please reply directly to my email as my spam filter occasionally deletes emails from the protel list...thanks! -- Peter W. Richards / [EMAIL PROTECTED] Design Manager, EE ph +1 (408) 737 8100 x113 fx +1 (408) 737 8153 350 Potrero Av Sunnyvale, CA 94085 This email message (and any attached document) contains information from Reflectivity, Inc. which may be considered confidential by Reflectivity, or which may be privileged or otherwise exempt from disclosure under law, and is for the sole use of the individual or entity to whom it is addressed. Any other dissemination, distribution or copying of this message is strictly prohibited. If you receive this message in error, please notify me and destroy the attached message (and all attached documents) immediately. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[EMAIL PROTECTED] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] double pins
At 10:21 AM 12/9/2003, Bagotronix Tech Support wrote: As to the old question of how Protel treats pads with the same name/number: we don't know for sure, and cannot find out. And anything we assume is likely to become incorrect across versions. So it's best to use unique pin names/numbers. Perhaps. First of all, it is quite clear how a CAD system should handle duplicate pin numbers. It should assign the same net to both pins. There is no other legitimate meaning for duplicate pad numbers: they are electrically identical, perhaps because they are necessarily connected by the inserted part, or because they are part of a complex pad structure. A common example would be a BNC connector with four ground pins. When the part is inserted, all four pins are connected together whether they are or are not connected together. The common schematic symbol for a BNC connector only has two pins. There are two ways to handle this: (1) create a new symbol for the connector which has four ground pins, each with a unique name. This is the Bagotronix solution. (2) use the classic symbol and place four ground pads in the BNC footprint. I find the second option much less cumbersome. For one thing, I'm going to continue to receive schematics and netlists from engineers who are going to have two-pin symbols, i.e., only two pins in the netlist, and I'm not the only one. Only if you have control of both the schematic and the PCB is the first option reasonable. Now, I just checked DXP behavior. I did not check all aspects of the behavior, for sure, but I found that if I made a footprint with a double pad, placed it on the PCB, used a part with only a single pad on the schematic, that pad being wired, DXP correctly assigned the same net to both pads. I then reran the update from schematic. No change, which is correct. So far so good. HOWEVER, Altium still didn't get it right. This is a bit irritating, since this matter has received a lot of virtual ink over the years. I removed the net assignment from one of the pads and reupdated. Schematic incorrectly reported that there were no changes. Then I deleted one of the wires on the schematic. This wire was connecting two of these double-padded parts. Updating the PCB correctly removed -- or attempted to remove -- the net involved. However, it only removed net assignments from one of the pin sets, the other maintained the net assignment (for both pads). This, however, is an unrelated problem: non-double-padded parts show the same behavior (a single node net is left, which is not correct). This is DXP SP2, BTW, fresh off of a new CD, I have not checked into further service packs, and I don't know if this has been discussed on the DXP list, since I've been off of it for a long time. (I'll go back) Exporting a netlist from the board produced double mentions of the pads, as might be expected. (I'm not sure if this is the best behavior, but at least it is quite reasonable; further use of that netlist would have to handle or eliminate duplicates.) While the behavior is a little buggy, it still functions correctly unless I toss it a curve ball by manually editing pin nets. Further, if the double pads are wired together in the footprint, DRC will catch any anomalies. Now, what happens with net list load? Unfortunately, I had trouble testing this as I could not readily find a means to import a net list into DXP. If all else fails, read the manual, and check out the Protel web Knowledge Base Ugh. Complicated. Powerful, yes, simple, no. That seems to be a DXP refrain. Unfortunately, OrCAD Layout had the same problem, part of the Protel advantage was intuitive interface, simplicity of use. All this could be corrected rather easily by adding in alternate paths of use that will be quickly found by a prior user I do think the DXP way is, in the long run, better. But, hey, how about considering your loyal users when you change the program? It would not take much to build in legacy methods, even if they only pop up a dialog saying this process has been replaced with And then there could be a control somewhere that removes or adds the legacy buttons or commands. The biggest complaint I have seen about DXP (in the Forum) has been its complexity In the process to import a netlist using Show Differences, there is a necessity to right-click in a dialog box to pull up a menu. Actually, there are two of these, the first one just to find Show Differences. Remember the famous hidden Update Free Primitives from Component Pads? It appears that the lesson was not learned. When there are advanced menus, there ought to be an indication that they exist! Anyway, double pads work well enough; in fact, netlist load now functions the same as update from schematic. And as far as future versions, I can hope that the remaining problems will be fixed. No way should pads with the same logical name -- except for free pads and no-name pads
Re: [PEDA] double pins
I thought Mr. Bagget's comments deserved a more detailed response. At 10:21 AM 12/9/2003, Bagotronix Tech Support wrote: Imagine if you were the Protel computer program. The user would need to tell you in an unambiguous manner how these double pins were instantiated. If they are given the same name, how can you tell them apart? Well, they will normally have different locations and possibly other characteristics (such as size). If you have two pads, part of the same footprint, with the same name and same location and size, ... you only have one pad and you have a possible problem with drill file operation In the examples under consideration, the pads will probably be identical except for location. The only way is if you, the program, assigns every object a unique object identifier, which is known only internally to you, and not to the user. Not true. The Protel ASCII database allows duplicate Pad primitives, and other kinds as well. There is no unique primitive identifier in the ASCII database, which would be why synchronization is lost by using the ASCII, a minor problem. However, identifiers are, I think, exported to spreadsheet. Does Protel do this? We don't know, and since we don't have the source code, we cannot find out. Therefore, we must use our own unique identifier. In Protel, the tools available to us to do this are pin names and numbers. So, we should assign a unique identifier to each pin in the pin pair. I'm afraid this is logical-sounding nonsense. We've been using double pads for a long time, and we have no difficulty with them beyond some anomalous behavior, quite predictable, of the program. But we don't need to know the difference between them, it does not matter to us if they are swapped (unless they are different shapes and sizes, in which case those characteristics also distinguish them). This is true as long as the program always assigns the same net to all pads with the same logical identifier (i.e., REFDES-PINNAME), with the exception of free pads and -- possibly -- pads with no name. As to the old question of how Protel treats pads with the same name/number: we don't know for sure, and cannot find out. I don't know why Mr. Bagget would say this. We can find out by experimenting, which is what we have been doing for a few years. It is clear that the Protel engineers were trying to fix the problem, but they simply didn't go far enough. The problems that exist are a result of making an assumption when programming that there are no duplicate pads. As a result, the first behavior was that the net was assigned to the first pad with the name and others were ignored. They fixed that, and on netlist load, in 99SE, both pads were assigned the name. Presumably netlist load now checked for additional instances. However, this created a new problem, because they did not check reload behavior. On reload, the program presumably noted that there was an extra pin in the net, and it created a macro to remove it. Then, because a macro was created to remove net XX from AA-B, and the macro implementation routine was fixed to handle double pins, the net was removed from both pins. This problem was fixed with the synchronizer in 99SE, as I recall but netlist load still exhibited it. But still they did not consider all the logical possibilities; most notably, what if one of the double pads has the net and the other does not? The DXP synchronizer thinks all is well, because, apparently, it fails to check for double pads. It finds a pad and net that match the schematic and it ignores the extra pad. It's really the same problem all over again. My guess is that this same problem exists in 99SE, I don't have time to check it today. It is not a problem that will arise unless one monkeys with the net assignments, deliberately or accidentally. It's unlikely, and DRC will catch it if the pads have been wired together. That's why I recommend wiring together double pads in the footprint, if they are to carry a net. If they are to carry separate nets, *then* they need unique names. And anything we assume is likely to become incorrect across versions. So it's best to use unique pin names/numbers. No, I think that if we assume that footprint pads with the same name get the same net, we will find that the behavior will be consistent with that, and minor bugs will be fixed. If implementing unique pin numbers is at all cumbersome (as with BNC connectors), intrinsically connected pads are better handled with a single pin on the schematic and multiple pads on the PCB. If a part has internal connections, however, so that, say, an SOIC has multiple grounds, the pins already have, normally, unique names, and using unique names would be the norm. Even there, an argument could be made for using multiple same-name pads, say with the name GND. But this is shakier, to be sure: I'd only consider it if it made the schematic easier to read, and it would require
[PEDA] OT: EuroCard Specs
Hi All, Can anyone point me towards a specification for a EuroCard PCB ? I'm after dimensions, standard connector positions, maximum height, etc. As far as I know the EuroCard is 160mm x 100mm but other than that I'm in the dark. Thanks in advance, Linden Doyle Product Development Engineer Zener Electric Pty Ltd. Ph: +61 2 9795 3600 Fax: +61 2 9795 3611 [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[EMAIL PROTECTED] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT: EuroCard Specs
Google works pretty well. Search for: EuroCard dimensions The first page has many sites that will show you the info you need. -Original Message- From: Linden Doyle [mailto:[EMAIL PROTECTED] Sent: Tuesday, December 09, 2003 6:41 PM To: PEDA Subject: [PEDA] OT: EuroCard Specs Hi All, Can anyone point me towards a specification for a EuroCard PCB ? I'm after dimensions, standard connector positions, maximum height, etc. As far as I know the EuroCard is 160mm x 100mm but other than that I'm in the dark. Thanks in advance, Linden Doyle Product Development Engineer Zener Electric Pty Ltd. Ph: +61 2 9795 3600 Fax: +61 2 9795 3611 [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[EMAIL PROTECTED] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
