Cadence PCB Design Forum

Routing in 16.6

Roger G — Fri, 24 May 2013 13:47:42 GMT

I am interested to find out how many ( if any ) are a bit annoyed by the new feature in Allegro 16.6 that when routing, if you change the size of the track to something other than the default size, it stays at that size until the USER sets it back to constraints. I find this possibly the most frustrating thing about this version. I through that this was a constraints driven tool, and as so should change back to the constraints, at the very least when you start the route command again.I dont want to keep having to go down the list on t he RMB to put it back to constraints tis is realy slow. If I get enough responses I will try again to get a service request through again. Last one got stopped.

Through Hole, both side routing.

raul5565 — Thu, 23 May 2013 20:07:14 GMT

Hello,

it may look stupid question but I am stuck with it.

I have a through hole connector on my 2 layer board for hight current (track width 5mm)

I would like to rout the track on both layers, of the connector, when i tries to do that the track on one side goes away.

and i am not getting tracks on both sides. (means singke ratnet needs to be connected from both layers)

can anyone help me with this?....

donut pad shape

nathan2009 — Thu, 29 Oct 2009 17:28:02 GMT

Hello,

I want to know how to create a donut shape symbol.It seems shape symbol can not hava a void in a shape.So how can I create a donut pad?

thanks.

Shape selection

ScottCad — Thu, 23 May 2013 03:57:45 GMT

When I have a shape for example a rectangle on the board and I pass the cursor over it the commands to do move,copy,rotate only become active via a RMB at the edge of the shapes bounding box. Was wondering if it is possible to configure Orcad/Allegro so that when find has shape checked and I pass the cursor over the shape be it in the center or other the shape highlights and the RMB menu becomes active.

I looked under setup user prefs but didnt locate anything that might apply to what I want to do.

This is not really a big deal as I can LMB window over part of the shape to select it that way too but it would be nice if it lit up like a christmas tree when I pass the mouse over the shape just based on "find" Similar to how it works if I draw a line.

Thanks Scott

OrCAD 16.3 dsn Format is not opening?

Dhamodharann — Fri, 24 May 2013 10:30:24 GMT

Hi...

I had drawn the schematic in OrCAD 16.3. but it was not opening in the OrCAD 9.2.But i read that in the forum, that want to save the format in previous version of it.

So I dont know how save the previous file format. So can anyone provide me the right solution to save the OrCAD 16.3 dsn to OrCAD 9.2 dsn.

Thanks & Regards,

S.Dhamodharan.

PCB Design Engineer

Artwork Log Message(Photoplot outline rectangle not found)

raul5565 — Tue, 21 May 2013 13:13:18 GMT

Hello,

I am getting the following message in my ViewLog file when I generate the Artwork files

"Photoplot outline rectangle not found ... using drawing extents"

not able to understand what exactly it means.

In my board design there is no keepout area, all components extends till the edge of a board.

If any one has an idea about this please reply.

Routing from a via

TH Designs — Thu, 23 May 2013 13:57:19 GMT

Updated to the latest service pack and I'm seeing a problem I have not run into before. Maybe I'm doing something wrong, but....

Below picture shows pairs of pins routed out to vias on the top layer. After laying these pairs down I now want to continue routing from the via on the bottom layer. I set my active layer to the bottom and click on the ratsnest near the via and my cursor jumps back to the IC pin and wants to route on the top layer. No matter what I try, I can not route from the via. It is sending me back to the IC pin. I have done this numerous times in the past and I'm wondering if it is a "feature" (bug) in the latest release, or is there some setting that I don't have set properly?

Tom

Allegro Viewer will not start after upgrade

Chris DeWitt — Fri, 03 May 2013 15:50:38 GMT

I just upgraded from allegro_free_viewer_16-5 to allegro_free_viewer_16-6. Right after the upgrade it worked fine but today I keep getting the message

This application has failed to start because callbackMgr.dll was not found. Re-installing the application may fix this problem.

I uninstalled and reinstalled the viewer but same results.

I did a regsvr32 "C:\Program Files\Cadence Design Systems\Allegro Free Physical Viewers 16.6\tools\pcb\bin\callbackMgr.dll" to register the dll but I get "Dll_Name was loaded, but the DllRegisterServer or DllUnregisterServer entry point was not found."

Output impedance of a buffer

tltoth — Wed, 22 May 2013 12:58:01 GMT

Hi,
Could anyone suggest a method to determine the output impedance of an iocell from ibis curves. The values from V/I curves are far from exact and the Trial and Error method is rather time consuming.
Thanks

MIL-STD-1553 trace routing

TH Designs — Tue, 02 Apr 2013 12:34:47 GMT

A lot of boards I have done over the years have used MIL-STD-1553 communications. Normally these were boards where the coupling transformers were located close to the connector. The manufacturer of the coupling xfmrs and transceiver recommends not having any power or ground planes directly under the 1553 traces. For previous designs this was not an issue. I am now working on a design where I have to route the 1553 through several boards before it gets to the outside world connector.

In order to not have voids through the planes, I am planning on routing the 1553 traces down the outer edges of the boards. I was just curious if there are nay designers out there that have 1553 experience and what their thoughts on this may be.

I have contacted the Applications Engineer for the pars we are using but he only refers me to the data sheet which is somewhat vague.

Tom