Author Topic: altium global net with harness  (Read 638 times)

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Offline hsn93

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altium global net with harness
« on: December 25, 2018, 07:13:53 pm »
hello,

my problem as following (I've hierarchical project):

in connectors sheet:


in mcu sheet:


now, the problem is this GND is considered as local and its disconnected from GND of the project. in both connector and mcu sheet parts.

i tried to play with (project options -> net identifier scope) but it just doesnt work..

how do you connect harnesses with ground pins that you just dont want to connect it in the (connector sheet)
 

Online Psi

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Re: altium global net with harness
« Reply #1 on: December 25, 2018, 07:30:02 pm »
i tried to play with (project options -> net identifier scope) but it just doesnt work..

have you tried recompiling the project after making those changes?
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Offline T3sl4co1l

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Re: altium global net with harness
« Reply #2 on: December 25, 2018, 07:53:48 pm »
Hmm, cool.  Nice to know, I guess...

Note: I don't have Altium open at the moment to test things, so I'm armchairing it here tonight... yeah...

What's wrong* with using a net bridge to allow the harness to use unique nets?
What's wrong with putting the supply symbols on the connector itself?  If I were reading that schematic, I'd sure as hell want to know which pins are on which supplies, without having to look at some damn other sheet to see where they're going...
Or for that matter, what's wrong with putting the ESD diode there too, or etc.?

*I know one thing wrong with this, in present circumstances: a net bridge needs to be spanned by a net bridge component, but we're talking USB ground here (in part), which needs to be solidly grounded, not lazily strapped in!  That would be an easy mistake to make here, between SCH and PCB stages.

Tim
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Bringing a project to life? We can help.
 

Offline hsn93

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Re: altium global net with harness
« Reply #3 on: December 25, 2018, 08:28:30 pm »
Quote
have you tried recompiling the project after making those changes?
yes, it just generate two different nets with same name.
if i use (strict hierarchical) it compile error of duplicate net name in the sheet.

Quote
What's wrong* with using a net bridge to allow the harness to use unique nets?
net bridge like this?:


hmm, i guess in most cases nothing is wrong but not all cases.

Quote
What's wrong with putting the supply symbols on the connector itself?  If I were reading that schematic, I'd sure as hell want to know which pins are on which supplies, without having to look at some damn other sheet to see where they're going...
Or for that matter, what's wrong with putting the ESD diode there too, or etc.?

concept of object oriented or hierarchical design..
i know i've been through this many times. but i imagine that connector sheet is for connector. maybe someone want to connect USB shield to ground or not.. he should look for the other sheet? .. so i though - connector sheet = connector only.

 

Offline T3sl4co1l

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Re: altium global net with harness
« Reply #4 on: December 25, 2018, 08:41:59 pm »
Hmm...

Basically, "that's just a netlist, with extra steps" (to paraphrase..)? :-DD

Let me explain: I don't see the harnesses being much advantage over just slapping net labels on every pin.  They provide a little more graphical sugar*, busing connections and showing where they go -- but it's still another mechanism of indirection, of not actually showing what components connect (touch) which other components.

*"Syntactical sugar", but in schematic form I guess? :)

Consider this -- I'm going to suppose that, given how many harnesses go between Inputs and Connectors, most of those connectors are actually inputs, as such?  Would it not be simpler, then, to place them there?  Or, as a sub-sub-sheet there?  Or to split the subsheet between an "inputs" piece, and an "everything else" piece -- or just putting the bits and pieces where they go?  What do you really gain by showing just connectors in one place?

Ultimately, as long as the connectivity is right, it doesn't matter, of course, but style matters for readability, and readability is the one-sided conversation from author to audience.  You are writing a document here, as much as in any other place, and communicating clearly should be the ultimate goal.  If your audience is yourself -- well, who cares, of course; but if a thousand technicians are going to be looking at it at some point or another, please take pity on them, they will appreciate it! :D

Tim
Seven Transistor Labs, LLC
Electronic design, from concept to prototype.
Bringing a project to life? We can help.
 
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Offline hsn93

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Re: altium global net with harness
« Reply #5 on: December 25, 2018, 08:53:44 pm »
Hmm...

Basically, "that's just a netlist, with extra steps" (to paraphrase..)? :-DD

Let me explain: I don't see the harnesses being much advantage over just slapping net labels on every pin.  They provide a little more graphical sugar*, busing connections and showing where they go -- but it's still another mechanism of indirection, of not actually showing what components connect (touch) which other components.

*"Syntactical sugar", but in schematic form I guess? :)

agreed. its not functional thing just *graphical sugar* ... in fact you can notice i colored the sheets also  :-DD :-DD :-DD

Consider this -- I'm going to suppose that, given how many harnesses go between Inputs and Connectors, most of those connectors are actually inputs, as such?  Would it not be simpler, then, to place them there?  Or, as a sub-sub-sheet there?  Or to split the subsheet between an "inputs" piece, and an "everything else" piece -- or just putting the bits and pieces where they go?  What do you really gain by showing just connectors in one place?

Ultimately, as long as the connectivity is right, it doesn't matter, of course, but style matters for readability, and readability is the one-sided conversation from author to audience.  You are writing a document here, as much as in any other place, and communicating clearly should be the ultimate goal.  If your audience is yourself -- well, who cares, of course; but if a thousand technicians are going to be looking at it at some point or another, please take pity on them, they will appreciate it! :D

Tim
i've big D-sub 37 pin connector there that includes everything..

i could just do like the "input -> mcu" sheet.. one harness called "connector_inputs" that include all sensors..

anyway, thats perfect i will start adding few things to connector sheet and ground, TVs there..
 

Offline T3sl4co1l

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Re: altium global net with harness
« Reply #6 on: December 26, 2018, 06:29:01 am »
I liked the colors, honestly; it breaks up the monotony of the default green. ;D

Oh, another idea -- if you're using a big fat connector, common to everything; what's wrong with putting it on the top sheet as such?  Then it's obvious what connects to where. :)  You probably have a lot of conditioning, transmitters/receivers, that sort of thing -- that could be put on a sheet, or repeated if it's common to a lot of channels, saving repetition of components. :)

Tim
« Last Edit: December 26, 2018, 06:34:49 am by T3sl4co1l »
Seven Transistor Labs, LLC
Electronic design, from concept to prototype.
Bringing a project to life? We can help.
 
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