Label Clarification

I’m using global labels on a multipage schematic and they have worked well. But, on a new schematic, I have a few connections to +15V and another lot to +3.3V and have used straight labels like those shown below with the understanding that these commonly labelled points would be joined in the netlist. However, they are not because in the rats nest they are missing. Can someone point me in the right direction?

Rgds

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Are they really labels or just text? Which button on the tools column did you use to create them?

If they really are labels they would be local ones from the appearance. If you want global power labels (symbols) you can find lots to choose from. If none of them suit you, take an existing one and rename it (in v7 you also have to rename the hidden pin in it).

Is this a hierarchical design? Local labels do not connect to other sheets, unless a label of another type and the same name is also in the same sheet.

I once read about a trick to use local labels for everything, and then make a list of global labels somewhere in a corner of a sheet. This gives nice a table like overview of all connections that go to other sheets.

No, this is not a hierarchical design - it’s just one sheet. In another design, the first image is what I’ve got all over the hierarchical design (multiple Vcc and Vdd per sheet for the various components) and the second sheet is what I’ve done with the global labels on each sheet. All devices are connected correctly, and the ERC comes up clean.

On this new design, for the +15V label, I used the ‘Add Label’ function in the ‘Place’ menu - it’s not a text remark. Quite strange.

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I don’t understand your example of your second (hierarchical) sheet screenshot. In KiCad all power symbols always act as global labels too. So renaming the nets by adding another global label is more confusing then explanatory to me. Use either method, but not both at the same time.

It’s hard to tell from your first screenshot whether the label has been positioned on the wire. The small square should disappear and I don’t see one so it should be connected…

An ERC would show if the +15V label is connected to nothing.

It would be much easier if you just attached the schematic.

But as I said, why not use a +15V power symbol which will be global should you decide to send that net to child sheets.

Hello Paul, on my top sheet, I have the main power connectors which I labelled V+, V- and 0V.

On each of the 4 remaining sheets below that, I used Vcc and Vdd at each of the opamps and other stuff on each sheet. Also then on each sheet, and only once, I added the global labels V+, V- and 0V. Here is a picture of the top sheet.

[I’m using V7 BTW. I will upgrade to 8 on my next project - just nervous about my libraries getting lost]

James, your comment “The small square should disappear and I don’t see one so it should be connected…” solved it. I checked for the little square (I remember seeing it when I was labelling up) using the ‘move’ command. One of the two labels on the sheet did not have the little square, so I don’t know what happened there - I must have misfired again :smiley: . Anyway, its fixed now and the +15V connection is working.

Thank you.

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