Due to a mail system error, this did not go out yesterday when it was written:

At 05:36 AM 5/14/2002 -0700, Fisher, Jerry wrote:
>Did you run an ERC to see if the resistor  is flagged with a connection
>error.

This is absolutely the first thing that should be done; and the ERC matrix 
should be set up to detect unconnected pins. If not, fix it.

I can hear the screams of pain from designers who have turned that ERC rule 
off because they get hosts of such errors and all or most of them are not 
actually errors.

But there is a better way; once one understands why a no-connection error 
is being found -- the most obvious and common is that the pin is 
intentionally unconnected -- one should put a No-ERC directive on top of 
the error marker; you will never again have to see that error. In fact, 
it's good practice to place the directive when you are wiring the schematic 
as a flag that the pin is deliberately NC.

Years ago, an engineer pointed out to me that checking all unconnected pins 
on a PCB layout was a good way to find errors quickly, as *most* errors 
resulted in an unconnected pin. This was with manual layout, tape and 
mylar. It's still a good idea, and the programs make it easy to find NC 
pins if you don't turn the warnings off!

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* 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/proteledaforum@techservinc.com
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Reply via email to