What is the difference between "Port" & "Off Sheet Connector" in Altium?

[matrixofdynamism]

This question is related to Altium Designer 21.

When doing schematic design in the Altium Designer, the Place menu contains these entires shown in the attached image.

The 'Port' and 'Off Sheet Connector' can both be used to cross reference things on other pages of the schematic. This much is clear. However, I am trying to figure out these things:

    1. What is the difference between the two? i.e How to know which one to use at a given time?
    2. Can't we just use net name from another sheet and they will still connect thus not needing the use of either of the above tools?

So far I have seen schematics that just rely on net name for cross referencing. I have also seen some schematics that use the two methods that this questions is related to.

I have found that Altium Designer has a concept of hierarchical schematic design. However, I am not referring to that in this specific question. Maybe the above symbols are also used for hierarchical design, I am not sure.

[tszaboo]

Off sheet connectors are "global" and supposed to have only 1 name.
Ports are "local" and if you place a schematic symbol, they appear on it. So you could have 5 ports named "output" on five different sheets, and they are not connected together, if you place the five sheet symbols.
I never really use Off sheet connectors.

[T3sl4co1l]

With Net Labels, all three connect globally in flat designs.  Semantically speaking -- take your pick.

I typically use OSC in flat designs, as a clearer visual indication that the net will be seen on other sheets.

The most common visual language when using labels, is a stub of wire sticking out, with the label on that.  Basically as a OSC but the label is on the wire instead of extending from it, and there's no arrow or eye-catching coloring.

Of course, this style is not required, so, you are still forced to stare at a stack of hay sheets, matching up net names, in case they might be used this way after all.  It's unfortunately easy to [mis]use net labels this way.

As mentioned, ports connect in the same way in a flat project, so are just a different visual language.  Personally, I prefer them to indicate hierarchical sheet connections.  Hence I use OSC when flat, and ports when hierarchical.

Note that, unless specified in project options, power ports are still global, so behave the way nets/OSCs do in a flat design.  If you select strict, you need to carry power through every sheet symbol, something of a PITA, but can be worth the trouble.

Tim