At 09:16 AM 6/12/01 -0400, John Branthoover wrote:
>Hello All,
> The major complaint that I have with the ERC function is that it
> can not
>distinguish between parts "J1A" and "J1a". I have a design where I was
>requested to break up an ISA connector into individual parts (62 pins) for
>clarity on the schematic side. Every time I perform an ERC on this design I
>get numerous "Duplicate Designators" errors. The net list however, is
>generated correctly.
>
> When I reported this error to Protel, I was informed that this
> is not a
>bug and that I was using Protel incorrectly. Oh well, It is tough being a
>rookie. ;-)
It's a bug. And, given how Protel is designed, it was being used incorrectly.
I do agree with Protel, however, that one should not rely on
upper-case/lower case distinctions. The problem here is that the part
section numbers are automatically assigned by Protel, so it could be said
that Protel is using Protel incorrectly.
The solution, for now, is to use numeric section designators
(Tools/Schematic/Multipart_Suffix/Numeric). This is a bit easier to
understand, anyway. In the case described, J1A becomes J1:1 and it
represents pin 1, and J1a becomes J1:33, which represents piin 33.
Mr. Branthoover didn't mention J1[ (J1:27) and the other non-alphabetic
messes created by how Protel assigns alpha part designations.... :-)
Yes, take my word for it. Bug. Undesireable behavior obviously not
anticipated by the programmers, or else they would have fixed it. For
example, if "alpha" is chosen for sections, then section 27 should be AA,
28 AB, etc. Base 26 representation using 26 letters as symbols, A = 0, B=1,
etc.
Better: a part attribute that specifies alpha or numeric part designation.
But that would not be as easy to implement. An easier-to-implement
compromise would automatically use A-Z for up to 26-section components --
if alpha is selected under Preferences --, and would revert to numeric
section numbering if there were more than 26 sections to the part.
But section numbering is often pretty useless.
One more reason to call it a bug: The sections are not duplicated; it is a
bug in the ERC routines that cause them to think that the first section is
the same section as the 33rd section. At the most ERC should generate a
warning that confusing designators are being used. But better solutions are
given above, I think.
[EMAIL PROTECTED]
Abdulrahman Lomax
P.O. Box 690
El Verano, CA 95433
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