Anlog and digital grounds don't connect when forward annotating to UB

[dbur]

I am randomly more often finding when I forward annotate to UB that the analog and digital grounds do not connect.  In additon some multisection IC power pin connections fail to be connected in UB.

Connect digital ground to analog ground is checked in my MS properties.

Is there any reason for this?

Thanks.

[supsup]

"Connect digital ground to analogue ground" - it is used for simulations, but not for transfer in Ultiboard

[dbur]

No, I have been using this method for many years to merge analog and digital ground when exporting to UB.

[supsup]

You are right. I have checked up - such connection is transferred in Ultiboard.

[dbur]

Turns out ot occur consistently when I have certain pages of my MS schematic active on top when I do the FA.  Works fine if I don't have any of those certain pages active on top when I do the FA.  This is a 7 page schematic.  Three pages cannot be on top when I do the transfer, or the grounds do not connect.  Bug has been submitted to NI.

[Mark J]

Hi all,

I'm pretty sure that this issue was fixed in the latest NI Circuit Design Suite 11.0.1 (released October 2010).

The issue was that the in hierarchical designs, the "merge digital and analog ground" setting was not properly being obeyed if the top-sheet wasn't selected. The temporary workaround is to always click on the top-level sheet before doing an export to Ultiboard.

However, I'd recommend upgrading to the latest version, it's got a number of improvements to our annotation system. If that doesn't fix the problem, please let us know.

Best Regards,

Mark J

National Instruments

[dbur]

Yes I do have all the latest, 11.0.1.  Problem is still there.

David B

[dbur]

Problem is still there in 12.0.653 as well.

The work around of exporting from page 1 of the schematic does not work either.  This is in a flat 3 page design with no heirarchy.

How do I get my analog and digital grounds to connect now?

David B

[Tayyab_R]

Hi David,

I did some testing with a small circuit and it seems to merge the grounds when I use the option in the Sheet Properties PCB Tab. Take a look at the attached screen shots.

In Ultiboard, it is possible to add a net bridge by going to Place -> Net Bridge. Then you can select both the nets (0 and GND) and merge them.

Hope this helps.

[dbur · Accepted solution]

Tien Pham offered this solution which worked:

I saw the ground issue in the file you sent and you can fix it by replacing
the digital ground with the one from V12.  On the Spreadsheet View, click
on the "Components" tab, select all the Dgnd symbols, next click the
replace icon on the Spreadsheet to replace all symbols at the same time.