Schematic working without bus wires?

Fairly new to Kicad and have created a few schematics over the past few months.

I thought I understood bus wires. They are used to link up wires and I’ve always included them in diagrams.

Today I was busy with a simple schematic and left off the bus wires but still had the labels on the wires and everything passes the ERC andeven in the PCB layout the rats nest shows the wires with the same labels connected together.

Pin 6 on U2 shows its connected to U1 pin 1 & 2…etc.

I thought this schematic would fail:

And needed to look like this:

So why are busses required? Does it just make the schematic easier to read or am I missing something?

At the moment the blue bus wires are purely cosmetic and KiCad depends solely on the labels attached to the wires to generate the netlist.

For some future version of KiCad there are plans to put more functionality into the busses.


Thanks for the info. I’ll continue to use them, just wondered why this was the case.


As @paulvdh already said, bus wires will eventually get true functionality. But until v6 they are mostly cosmetic only. Very useful cosmetics IMHO to make schematics easier to read.

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There is one exception to buses being simple graphic lines. You can connect a bus to a global label or a hierarchical sheet pin instead of using multiple such labels. This works if your bus connections are of the style common_prefix# (with # being an integer) you can then use labels of the form common_prefix[1…n] to connect a full pus via them. (In future it will be possible to do the same with named signals on a bus.)


Some nice tricks there on that page you linked, Rene. I didn’t know about the correction of mismatched labels trick.

Is any label with a diamond a “global label” in eeschema ?

It can be a hierarchical bidirectional label.

But to be sure, select the label and press “e”. It will tell you what kind of item it is.

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