Schematic-vs-PCB Differences

On 5/29/2012 7:49 AM, Paul Horst wrote:

I am having a problem with connections on the schematic not following through to become nets on the layout drawing. Is this a common problem with EAGLE? I am using a standard library part and a part that I created, so it is possible that my part will simply not connect to the net. I had no problem making the connection on the schematic, though, so I don't understand why it doesn't connect on the PCB.

 

Any help would be appreciated.

 

If the grid is different between the part and the schematic it may look

connected but not be. You can adjust the grid or set an alternate grid

for this.

If you grab the wire near the connection and it moves by itself then it

is not connected. Another common thing is if one uses wire instead of

net to make connections,

-D

Thanks, Doug. I checked the connections on the schematic like you suggested and the connections are solid. I have been using the wire tool to make all of my connections, though. Should I be using the net tool instead? I tried using it to replace the connection in question, but it won't connect to my part. This is a part that I created myself, so there is a distinct possibility that I made a mistake on it. I am trying to connect to an output pin that I created as an output on the symbol.

Thanks again,

Paul

On 5/29/2012 10:18 AM, Paul Horst wrote:

Thanks, Doug. I checked the connections on the schematic like you suggested and the connections are solid. I have been using the wire tool to make all of my connections, though. Should I be using the net tool instead? I tried using it to replace the connection in question, but it won't connect to my part. This is a part that I created myself, so there is a distinct possibility that I made a mistake on it. I am trying to connect to an output pin that I created as an output on the symbol.

 

Thanks again,

 

Paul

 

Yes, you should be using the net tool for connections.

Not intuitive, but once you know it is ok.

The most likely issue is the grid being different between the library

part and the schematic. Check the grid on the part and compare it to

what is on the schematic.

Paul Horst wrote:

>I am having a problem with connections on the schematic not following through to become nets on

>the layout drawing. Is this a common problem with EAGLE? I am using a standard library part and>

>a part that I created, so it is possible that my part will simply not connect to the net. I had no

>problem making the connection on the schematic, though, so I don't understand why it doesn't

>connect on the PCB.

are you sure board and schematic are still consistent?

Consitency may be lost if you change the schematic (adding/deleting

parts/nets is relevant, just moving things around is not a problem)

while the board file is closed.

Run ERC to check.

I don't think wire vs. net command is an issue here.

The main difference between wire and net commands is the fact that the

net command will place connection points automatically, where the wire

command does not (so a connection and a crossing lock to same).

The easiest way to see if nets/wires are connected to a part is to

pick up the part and move it. All connected nets will follow the part

in that case (use ESC to abort the move without modifications).

--

Lorenz

"Paul Horst" <noreply-105171@element14.com> wrote in message

news:1807090506.20961338302985506.JavaMail.jive@flmspu-csapp-02.premierfarnell.com...

>I am having a problem with connections on the schematic not following

>through to become nets on the layout drawing. Is this a common problem with

>EAGLE? I am using a standard library part and a part that I created, so it

>is possible that my part will simply not connect to the net. I had no

>problem making the connection on the schematic, though, so I don't

>understand why it doesn't connect on the PCB.

 

Any help would be appreciated.

 

Probably not the source of your problem but if you turn off connection dots

in control panel, Eagle does not take the same care in making sure that

wires butted up against each other will get connected. Connections are more

hap-hazard than if you throw down a connection dot.  It makes me feel like

odd-man-out but I absolutely refuse to have those horrendous oversize

connection dots cluttering up my schematic. Must run ERC from time-to time

but the issue is not really very seriously treated according to Eagle (huh

really!). Make sure that messages like "Close but unconnected wires in nets

n$1 and n$1, do not go ignored.

In the schematic editor, select Options || Misc || Auto set junction

(junction, meaning the dot).