Renaming a component without shifting the numeration

Drawing Schematics, Hierarchical Design, BOM, Exporting net-lists, etc.
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Posts: 3
Joined: 07 Feb 2018, 10:57

Renaming a component without shifting the numeration

#1 Post by zioelp » 07 Feb 2018, 16:01

I'm often in need to manually copy some old schematics in paper form (no CAD file), maintaining the original RefDes in the new DT document.
Now, if a begin from scratch and verbatim copy R56, C21, Q2 and so on, I can quickly buildup a machine readable schematic without effort.
In quite a number of cases, I encounter two versions of the same circuit, where the second has the same components, the same netlist arrangment, but randomly different RefDes.
Now, I would like to copy & paste the first onto a new document, and simply amend only the RefDes where necessary.
Is there a way to change a RefDes without affecting the numeration for the other ones?
I recognize that allowing the user to change, let's say, C1 to C5 when C5 already exists would temporarily broke the internal consistence of the netlist, but why don't allow a simple swap of C1 and C5, instead of messing up from C6 to the infinity and beyond? :-)

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Joined: 20 Jun 2015, 14:39

Re: Renaming a component without shifting the numeration

#2 Post by Tomg » 08 Feb 2018, 07:09

Yes, it would be nice to have a tool available in the right-click pop-up menu to accomplish this task, perhaps with a name like "Swap RefDes". In the meantime, do what I do...
1) Renumber "C1" to "C5new".
2) Renumber "C5" to "C1".
3) Renumber "C5new" to "C5".
Doing it in this manner will prevent "infinite" renumbering and help you keep track of which reference designators are being swapped.

p.s. After changing reference designators in the schematic and resaving, run the Renew Layout from Schematic tool in the PCB Layout editor. If instead you have changed reference designators in the PCB Layout editor and resaved it, use the Back Annotate tool in the Schematic Editor.

Posts: 3
Joined: 07 Feb 2018, 10:57

Re: Renaming a component without shifting the numeration

#3 Post by zioelp » 08 Feb 2018, 14:56

That's a smart solution, but I also tried this one: I write two zeros following the digit of the "destination" RefDes, so that C5 becomes C500, then I change C1 to C5.
After the last correction, I simply look at the list of parts in the Design Manager window, and if I see a RefDes greater than 100, I know that something went wrong :-)
No need to say: should the original schematic had more than 100 C RefDes, I would enqueue three zeros instead of two.
Another CAD package I used in the past (roughly same price range of DT), would even accepted the same RefDes more than once, reporting a warning list with a specific DRC tool and refusing to export a netlist to a PCB until all the RefDes were uniques.

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