what is the best way to re-route multiple parts in same package and choose connectors with Diptrace

Question

I am using Diptrace to route a board with over 1200 pins.

It's a fairly dense board with lots of SMD devices and I am using some resistor and capacitor networks, as well as dual MOSFETS and a large cable connector.

I have the luxury of using whatever connector on the cable I want, and the resistor and cap network pins are fairly interchangeable for me. For instance, they are all 10K resistors and I can exchange them for whatever other adjacent resistor or capacitor that is more easily routed.

So my question is when using Diptrace (or even in another package) to do the routing, is it acceptable or usual to just change the nets on the board when routing, or should I go back to the schematic and change the pins there and re-sync the layout with the schematic? Or is there a way to set Diptrace up so that any pin can be used as long as the part is the same? How do you handle this? Or is there another better technique?

Answer 1

Sure, this is a pretty standard feature in a lot of PCB design packages. It's generally referred to as "Back Annotation." While I haven't used Diptrace, both PADS and Altium Designer provide this feature, though I used it very sparingly.

According to the Diptrace FAQ:

If you have made changes in PCB, use Back Annotate feature in Schematic (select "File \ Back Annotate \ ... " from main menu) to bring changes from the board into the circuit.

This should update your schematic with the changes you've made while routing the board.

The key is consistency. If you're not diligent about updating the schematic to reflect any changes you've made in the layout, then it's pretty easy to get lost.

I will also say that I've tended to use forward annotation (updating PCB with schematic changes) more than back annotation simply because it seemed to be easier for the software to handle, but it's definitely worth a try. Just make sure to back up your board files first!