1 2 First Previous 15 Replies Latest reply on Jul 16, 2018 5:39 AM by phiet

Reference Designator Problem

alexb0 Jul 9, 2018 8:28 AM

Hi all,

I really need an explaination about the reference designator as shown in this topic: https://support.mentor.com/en/product/852852099/knowledge-base/MG80631

1) Why for some components, there is this problem and for others, there is no problem? For the moment I have this problem only for CAPACITOR...

2) I followed the topic in the goal to change the ref des.

- For the first capacitor on my design, no problem with the 2 methods.

- For a second reference, it's impossible for me to change the ref des of this capacitor... I deleted the "C?" on the symbol editor, package with "Delete local data, then rebuild all local lib data" but the ref des still "U145" instead of "C145".

Thanks for information.

Regards,

Alex

1. Re: Reference Designator Problem

alexb0 Jul 12, 2018 2:39 AM (in response to alexb0)

No one ever had this problem?
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2. Re: Reference Designator Problem

phiet Jul 12, 2018 6:44 AM (in response to alexb0)

No, because we have matching Ref Designator properties on components and Prefix in Library ... We don't use mix

[quote] It is best to have the Ref Designator property on your symbols correspond to the Reference des prefix as set for a partition in Library Manager. As an example, capacitors that have a C? Ref Designator property value should have a Reference des prefix of C in Library Manager for the capacitors part partition.[quote]
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3. Re: Reference Designator Problem

alexb0 Jul 12, 2018 8:39 AM (in response to alexb0)

The problem is there is a matching between our symbol property and the prefix in part definition.
I really have no idea where the prefix "U" comes from (for this component)...
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4. Re: Reference Designator Problem

phiet Jul 12, 2018 8:53 AM (in response to alexb0)

is it possible that there's mismatch before and it's now corrected ?
in that case, that U became "block value" and cannot be overwritten...
in such case, delete the actual value and repackage (with update PDB and delete/update local lib option) should take care of this.
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5. Re: Reference Designator Problem

alexb0 Jul 12, 2018 11:16 PM (in response to alexb0)

Hi phiet,

is it possible that there's mismatch before and it's now corrected ?
in that case, that U became "block value" and cannot be overwritten...

Indeed, that is true but I tried to delete the value and repackage with Update properties in first, no result and then I deleted again the value and repackage with delete local librairy but not works for this component.

Info: I had another capacitor with the same problem, as I said in my first message (case 2), but it works for this one so I don't know why it works sometimes and sometimes not...

Thanks

Alex
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6. Re: Reference Designator Problem

phiet Jul 13, 2018 5:20 AM (in response to alexb0)

I reread your first message.You only deleted the C? value in the symbol. In fact, you think have also to delete the existing value of the Ref Designator in the schematic and repackage and do not forget to check the option "update PDB properties on symbol". This worked for us.
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7. Re: Reference Designator Problem

phiet Jul 13, 2018 5:22 AM (in response to alexb0)

btw, are 2 capacitors same part number ?
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8. Re: Reference Designator Problem

alexb0 Jul 13, 2018 6:13 AM (in response to alexb0)

Indeed, I forgot to write that I also deleted the instance value in the schematic...
I just made a short video of my problem. I created a new project with only one capacitor.

1) I deleted the "C?" definition in the symbol:
2) Part definition of the capa:

3) See the video (GIF) of packaging.

Info 1: In the video, I tried without the "Update PDB properties on symbol" but I also tried with this option, same result.
Info 2: As I said, this problem occurs only with some part references, not all... The symbol is the same beetween of of these capa.

Thanks

Alex
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9. Re: Reference Designator Problem

phiet Jul 13, 2018 6:23 AM (in response to alexb0)

In the video, you do not have :"update PDB properties on symbol" checked .
Also, it will be interesting to see properties panel when you add you cap...
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10. Re: Reference Designator Problem

alexb0 Jul 13, 2018 6:28 AM (in response to alexb0)

Yes, but I also tried with this option (Info 1) but nothing has changed.
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11. Re: Reference Designator Problem

cesario_espiritu Jul 13, 2018 10:55 AM (in response to alexb0)

To fix it permanently, it should start from Lib.
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12. Re: Reference Designator Problem

alexb0 Jul 16, 2018 12:15 AM (in response to alexb0)
To fix it permanently, it should start from Lib.
Can you explain with more details please?
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13. Re: Reference Designator Problem

robert_davies Jul 16, 2018 4:04 AM (in response to cesario_espiritu)

I would suggest you remove all of the property values of ? as they are unnecessary, if you switch on Place holders in the symbol editor you will be able to see where the values will appear during packaging and back-annotation. As to the REFDES, you can leave that as C? Once you have made the changes perform a symbol update in the schematic.
Re-run packaging using the Update local library data with newer central library data.
If it doen't fix the problem then provide a screenshot of the Ref Designator property in the Properties pane so we can see the symbol, block and instance values clearly.
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14. Re: Reference Designator Problem

alexb0 Jul 16, 2018 5:03 AM (in response to alexb0)

Hi Robert,
The only property we put on our symbols is the RefDes (C? for capa, R? for resistor...).
Info: I made a new project with only one capa.
1) I rerun a packaging with "Update local library data" and "Only Extract Missing Library Data": The Ref Des stays at U1
2) I rerun a packaging with "Update local library data" and "Delete local data, then rebuilt all local lib data": The Ref Des stays at U1

Here, a screenshot of my component. The "C?" in the symbol defition was deleted in the goal to try the phiet suggestion.

Alex
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