Update Layout from Imported Netlist

Making PCB Layouts, Manual routing, Auto-routing, Copper pouring, Updating from Schematic, Manufacturing Output
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Posts: 6
Joined: 05 Oct 2017, 22:40

Update Layout from Imported Netlist

#1 Post by crj11 » 14 Oct 2017, 23:26

I have successfully imported Protel format netlists into the PCB Editor and created a PCB. However, I have not found any way of importing an updated netlist without overwriting the existing layout. I know that this is possible for DipTrace schematics. Is there any way to do it with a netlist generated from an external schematic program? Assuming that it is ASCII, I could probably create an updated external netlist and/or partlist in the format generated by the DipTrace schematic program, if that would help. This assumes that DipTrace Schematic creates a file that is then read in by the PCB editor.

Any help on how to accomplish the main goal of updating a PCB layout with a slightly changed imported netlist would be greatly appreciated.


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Joined: 20 Jun 2015, 14:39

Re: Update Layout from Imported Netlist

#2 Post by Tomg » 15 Oct 2017, 06:09

I have no experience doing this, but that never stopped me from dispensing bad advice before. Try the following if you haven't already...

1) Create the schematic and make sure its reference designators and components match up with the PCB (same patterns, pinouts, etc.) as much as possible.
2) Resave the schematic.
3) Update the PCB using the "Renew Layout from Schematic" tool and its "By RefDes" option.
4) If that doesn't dismantle your layout then resave the PCB, go back to the schematic and run the "Back Annotate" tool as insurance just to make sure most everything matches. This will bring the reference designators, values and types of components, net names, and net classes from the PCB to the schematic, but will not add new components or nets. If everything looks good, resave the schematic.

If all of this is successful, future PCB renewals can be done using the "By Components" option. I'm curious to find out what happens so please let me know whether or not the layout gets dismantled again.

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Joined: 21 Jan 2019, 14:39

Re: Update Layout from Imported Netlist

#3 Post by JoR » 24 Sep 2019, 15:42

I've made some tests and the way to do this (with Orcad) is exporting the schematic to EDIF and then import to Diptrace. If you generate a PCB, and then import again the updated schematic EDIF from Orcad, the changes are applied to the PCB through the "Renew Layout from Schematic" option.

However, this way you have to maintain a components library and a footprints library in Diptrace, instead of only the footprints library in the case of using an external netlist instead of an EDIF schematic, as I don't see the option to import the PCB Footprint field from the EDIF (and anyways, a netlist seems a much more reliable source than the EDIF schematic).

For sure the priorities must be polishing the complete workflow in Diptrace, but for cases as mine (the official schematic tool in my company is Orcad Capture and I'm trying to convince my boss to use Diptrace for PCB routing), a "Renew Layout from netlist" option would be nice, and doesn't look terribly complicated to implement.

Thank you!

Note: the netlist formats from Orcad that worked for me were Accel, PADS, P-CAD and Protel (with the Tango format, the "_" weren't imported correctly).

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