Labels, networks, and multiple names

Schematic
#1

I am on KiCAD 6.06 and have pared down my problem to the simple attached schematic. I am redrawing an Orcad board in which the prior author gives names to various networks, including those associated with power networks. I see some problems here:

  1. If I grab the upper right corner trace, I see that “test1” moves with its connector and “test2” does not. What is happening here? I played a bit with it and cannot always seem to associate labels with their networks.

  2. Are labels just that----labels—or do they have a deeper electrical significance in KiCAD. The seem to actually designate network for example.

  3. if you run an ERC you will see a complaint about the redundancy between between 12V and “test1”. Fair enough, and this is only a warning–but are multiple networks names not acceptable?
    Interestingly “test2” is fine because it is just 'floating" e.g. not associated with a connector.

CPICS_test.zip (9.8 KB)

Thanks
Fritz

#2
  1. Both the labels “test1” and “test2” are connected to the wire (Just as the label “+12V” from the power symbol.
  2. Labels make electrical connections.
  3. It is legal to make an electrical connection by connecting two labels together with a wire. The label “test2” is also connected to the wire. If a label is not connected, you see a small black square in one of it’s corners.

I get the warning for test2. Not for test1.

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When I drag the upper right corner, sometimes “test1” and “test2” stays connected, which is a bit weird. KiCad sometimes gets confused if wires get dragged diagonally. The important thing is that as long as you do not see the small square in the corner of a label, it is connected. You can also verify that “test2” is also connected by dragging the vertical wire segment that “test2” is connected to. The label will move with it.

Another way to verify the label is connected is with: Schematic Editor / Tools / Update PCB from Schematic [F8]. The first time you do it, pad 1 of the C10 has the +12V net name. If you remove the power symbol from the schematic and [F8] again, then pad 1 of C10 gets the test1 label, and if you also remove that and update again, then it gets the test2 label.

#3

I fail to understand the intention. Why give the same net different names/labels?
It’s either muddled thinking, or a need for obfuscation (which is understandable, but never works in defeating reverse engineering).

#4

OK Paul-now I see the erratic behaviour of the labels. Sometimes when I drag the corner (with g) “test1” moves—other times “test2”–but never both. Probably a bug, yes?
Regarding multiple labels on the same net–I think you are indicating that this is fine, and just ignore the warnings?
I don’t believe there is a way to list all of the nets being used ( I think that was different software).

ML9104–you are onto something there. Not sure why the original author used multiple names–(he is off on the RV Atlantis for 2 months). At any rate I think he was just trying to emphasize the purpose/use of various nets connected to GND, 12V etc. Non electrical labels would make sense here but I don’t think that “Text” can be given affinity to a wire when moving it.
At any rate I really need to keep these labels as this schematic will probably leave my lab and be used by others who are used to it.

thanks all
fs

#5

RV Atlantis? Oh, one of Woods Hole’s research vessels. Very cool. According to Where is Atlantis Now? - Woods Hole Oceanographic Institution they appear to be docked in San Juan, Puerto Rico.

1 Like
#6

Yep. Not sure where they are headed but this ship holds the Alvin sub.
Fortunately once research equipment leaves the institution I rarely go out with it. I get seasick and life on a research vessel isn’t for all of us.
thanks
fritz

1 Like
#7

Just killing time tonight so watched ‘The Most Unknown’ tonight on net flix and towards the middle, there was Alvin. Kinda funny before they mentioned the name, I’m kinda like, 'No this can’t be the same vessel from the Kicad forum thread… ’ :wink:

#8

How’s that for an advertising slogan: “KiCad – almost kind of mentioned in Netflix”.

As for the question 1: v6.99 behaves differently. There’s a bit more intelligence in horizontal/vertical dragging, it tries to keep the lines h/v and keep the connections. When I press the mouse button on a label and drag it, it inititates the Drag function which keeps the label connected with a new wire segment.

KiCad relies on the label and the wire existing in exactly (or maybe almost exactly) the same coordinates, so with other than horizontal/vertical wires it may be even impossible to the label to stay attached. I think in 6.99 with h/v lines only it’s easier to keep things connected than in v6.0.

You can of course ignore the warnings if you know what you are doing. I would avoid that in normal cases (your case here is different). IMO the automatic net naming according to some order using power symbols and pin names isn’t a good thing, an explicitly given label should always be given preference – why would someone ever give an explicit name otherwise? And only one name should be given explicitly.

#9

Maybe it is the other way around–we should say that KiCAD mentioned Netflix! :grinning:

The dragging issue is not to critical but was just a bit confusing when i was trying to get my mind around the issue.

Regarding the “multiple label” eelik’s post clearly stated what I was not sure about. I think your idea regarding choosing the label makes sense-maybe the label creation panel could have an “alternate names” section in its Properties.
I know that all this concern over labels may seem like “gilding the rose” to some-- heck-I don’t ever use multiple labels in my own designs. But I see the value in the case I am migrating here–when there are a LOT of wires/interconnects running around, generic label indicators aren’t that useful and having names is helpful. The problem seems to mostly arise from sharing these names with power labels automatically generated such as GND, 3.3V and so on.

Thanks all
Fritz