Electrical schematic entry software / Subcontracting cabling
stijnva...@hotmail.com
Our company has a recuring problem : subsystems send out for cabling
at subcontractors are often returned miswired. It seems that they
always misinterprete our schematics. Partly i think this is because
the people whoe actually carry out the cabling are not electrical
engineers.
The electronic schematic entry and pcb layout software we are using
are working out well for our electronic (pcb based) projects. But we
don't find them very user friendly for designing cabling, cable
harnasses, subsystems etc.
I think that most electronic schematic entry software don't allow very
well to represent how a real system is build. While most mechanical
CAD software do a very good job at representing the physical world,
they do a poor job representing an electrical schematic. (ea Autocad
Electrical)
Does anyone knows affordable packages that fill the gap between pure
electronic and mechanical cad. (We don't need much rule checking and
automation)
Thx
Stan
Paul E. Bennett
It depends on the type of cabling you are needing. If it is straight end to
end between connectors (with limited links) then a cable schedule can be
created in a spreadsheet package without too much effort (I use these a lot
where I am working currently - but then we have a lot of cables). If the
cable has some links at the connector these can be shown as drawn on
bridges with the later versions of Excel and Open Office.
If it is an internal to a box cable loom then you may find that some PCB
schematic capture packages are able to do that much better. These packages
need to properly manage hierarchical design levels (OrCAD is a bit clunky
in this respect but UltiCap and Ultiboard - now part of Electronics
Workbench - was better at it).
Also, behind the electrical/electroinc CAD packages there is usually a
mechanical CAD package and you should maybe explore that also. OrCAD comes
with IntelliCAD which can deal with CAD in 3D. This may take some getting
used to.
--
********************************************************************
Paul E. Bennett...............<email://Paul_E....@topmail.co.uk>
Forth based HIDECS Consultancy
Mob: +44 (0)7811-639972
Tel: +44 (0)1235-811095
Going Forth Safely ..... EBA. www.electric-boat-association.org.uk..
********************************************************************
Tim Wescott
Proper cable drawings, of the sort that I've seen for avionics equipment
(which tend to have _lots_ of cables) don't look much like schematics.
I've only been close enough to see them done in one place; there they were
done in Autocad, and the folks doing them were quite happy with the
process.
--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com
Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html
Leon
>
> Need to learn how to apply control theory in your embedded system?
> "Applied Control Theory for Embedded Systems" by Tim Wescott
>
> - Show quoted text -
Most aircraft these days are designed with Dassault's CATIA, I'm quite
sure that it has a module for designing cabling and fitting it within
the airframe. It's a very expensive piece of software, though.
Leon
Guy Macon
stijnva...@hotmail.com wrote:
>Our company has a recuring problem : subsystems send out for cabling
>at subcontractors are often returned miswired. It seems that they
>always misinterprete our schematics. Partly i think this is because
>the people who actually carry out the cabling are not electrical
>engineers.
>
>The electronic schematic entry and pcb layout software we are using
>are working out well for our electronic (pcb based) projects. But we
>don't find them very user friendly for designing cabling, cable
>harnasses, subsystems etc.
>
>I think that most electronic schematic entry software don't allow very
>well to represent how a real system is build. While most mechanical
>CAD software do a very good job at representing the physical world,
>they do a poor job representing an electrical schematic. (ea Autocad
>Electrical)
>
>Does anyone knows affordable packages that fill the gap between pure
>electronic and mechanical cad. (We don't need much rule checking and
>automation)
Here are some of of the more well-known packages:
WireCAD Pro $1499
WireCAD XLT $999
WireCAD XL $399
http://www.wirecad.com/
CableCAD $7,495
http://www.cablecad.com/
Solid Edge Wire Harness Design / XpresRoute
http://manufacturing.cadalyst.com/manufacturing/article/articleDetail.jsp?id=282640
Solid Edge XpresRoute Node Locked: 995.00 / Year
Prerequisite: Solid Edge Classic - Node Locked
(1,296.00 / Year)
Solid Edge XpresRoute Floating: 1,795.00 /year
Prerequisite: Solid Edge Classic Floating (5,095.00
/ year per seat, minimum order of five seats)
The only one of the above that I have personal experience
with is Solid Edge without XpresRoute, and I like it a lot.
Some folks like Solidworks or Autodesk Inventor better;
I don't know how well they do harnesses. I have worked
with full Autocad, and in my opinion using it for cable
diagrams is like planting a tulip with a bulldozer.
That being said, I would question the reason *why* you have a
recurring miswiring problem. You are assuming that the problem
is with your CAD software, but you didn't specify exactly what
features you think would help, which (along with your comment
about wishing that the assemblers were EEs) makes me suspect
that the problem is that the people on your end who are making
the drawings are not "speaking the same language" as the people
making the wiring harnesses. This is quite common; EEs who
speak the same language as PWB houses are more common than EEs
who speak the same language as cable harness houses.
I would also at least ask whether a repartitioned overall
design with a simpler cabling harness is possible. Again,
EEs who make really good PWB designs are more common than
EEs who know how to make really good wiring harness designs.
Depending on the size of your company and how many designs you
do per year, it might make sense to hire an engineering consultant
to come in and review your design process from top to bottom.
There are several folks in in this newsgroup who would be good
choices, but a lot depends on where they live and where your
company is located.
--
Guy Macon
<http://www.guymacon.com/>
Jim Granville
Do you also send netlists ?
What sort of errors do they make - incorrect nets, or incorrect wire
stub lengths, or incorrect crimp details ?
A good SCH Entry program, with some simple library effort
and reports, should make this less confusing ?
ie
** Netnames can be the wire colour codes,
** Nett Attributes can include mfg comments
** Stub dimensioning arrows/text can come from the librtary as
2D combined lines/text
** Connector Attributes can expand to include Terminal.CrimpType
** Connector Attributes can expand to include Terminal.WireSize
etc
all of those are possible in Mentor's PADS Logic (Mid priced?),
and it has a report scripting language, so you can massage
the info into almost any format/sorting you want ( as well as the usual
graphical printout )
-jg
stijnva...@hotmail.com
Thanks for the insights.
> The only one of the above that I have personal experience
> with is Solid Edge without XpresRoute, and I like it a lot.
> Some folks like Solidworks or Autodesk Inventor better;
> I don't know how well they do harnesses.
We do use Inventor for all mechanical CAD, but we never used the cable/
harnass function. Maybe we should use it give it a try and search for
a good workflow between 2D Electrical cad and the 3D harnassing module
in Autodesk.
> That being said, I would question the reason *why* you have a
> recurring miswiring problem. You are assuming that the problem
> is with your CAD software, but you didn't specify exactly what
> features you think would help, which (along with your comment
> about wishing that the assemblers were EEs) makes me suspect
> that the problem is that the people on your end who are making
> the drawings are not "speaking the same language" as the people
> making the wiring harnesses. This is quite common; EEs who
> speak the same language as PWB houses are more common than EEs
> who speak the same language as cable harness houses.
Indeed, it's not just about software. It is about how to document and
communicate.
I think the problem is about actually building a real world item from
a 2D drawing. Where actually is Pin 1 ? Do you count pins at the back
or front from a connector ?
As a EE we just assume certain thing. A red wire to earth and a yellow/
green wire to 100V rings a bell while assembling a system. For the
girls and boys in subcontracting these are just all 'wires'.
I think they need a much more 'mechanical' drawing. Where they realy
see in 3D where each wire goes. But drawing all connectors and wires
in 3D is a lot of work compared to a 2D electrical schematic. This is
the reason why i started looking for a easy to use 'mixed' package
preferable with a basic library.
> Depending on the size of your company and how many designs you
> do per year, it might make sense to hire an engineering consultant
> to come in and review your design process from top to bottom.
> There are several folks in in this newsgroup who would be good
> choices, but a lot depends on where they live and where your
> company is located.
Good idea. I started looking for a good consultant a while ago. But
didn't found the right person, that realy understand the whole problem
(besides documentation there are other 'cabling' issues: reliability
in a harsh enviroment, easy diagnostics, EMC and CE issues, safety..)
We are a SME based in Europe. If anyone feels that he could do a good
consulting job on this, he is very welcome to contact us.
Stan
stijnva...@hotmail.com
No, we send a electrical schematic and photographs of a prototype.
> What sort of errors do they make - incorrect nets, or incorrect wire
> stub lengths, or incorrect crimp details ?
All sorts of errors, they sometimes wire a circular corrector in the
wrong directions, they insert the male contacts into female
connectors, mistake black/white and white/black wires.. I could
offcoarse blame the subcontractor, but i think that sometimes they
just don't know howto.
> A good SCH Entry program, with some simple library effort
> and reports, should make this less confusing ?
>
> ie
>
> ** Netnames can be the wire colour codes,
> ** Nett Attributes can include mfg comments
> ** Stub dimensioning arrows/text can come from the librtary as
> 2D combined lines/text
> ** Connector Attributes can expand to include Terminal.CrimpType
> ** Connector Attributes can expand to include Terminal.WireSize
ok. I agree. Maybe is should include much more details. I take it for
granted that they use the correct terminal for a certain wire size..
Maybe i should add much more details.
Anton Erasmus
You can look at a package called Harnware. Raychem (Now bought out by
Tyco IIRC) used to give away a license to this package if one placed a
reasonable sized order with them. It is quite easy to use,
specifically for military type harnesses.
Regards
Anton Erasmus
Jim Granville
You can never give too much information :)
Certainly a netist would help, and if the connector housing has
clearly stamped numbers, use those, or a simple end-view
(clear for which end, of course! )
On the cables we get, they supply us their manufacturing drawing,
and in most cases, also a sample they built.
They _should_ have this, as what if you order a second batch ?
- they also should generate a unique part number for each drawing
revision, and the drawing should be unambigious.
Our asian supplier is pretty good, but we caught them a couple of
times not revising drawing/part codes for changes.
The drawing had RevJ signed off, but the part number, and drawing name,
did not change.
They number all connectors, and have a simple matrix table of colours,
and pin-pairs.
-jg
Guy Macon
Content-Transfer-Encoding: 8Bit
Anton Erasmus wrote:
>You can look at a package called Harnware. Raychem (Now bought out by
>Tyco IIRC) used to give away a license to this package if one placed a
>reasonable sized order with them. It is quite easy to use,
>specifically for military type harnesses.
They appear to now be charging an annual license fee of Ł250
There is a download here:
[ http://www.harnware.com/downloads/HarnWareV4_5_29.zip ]
It's 4.3 MB and I am on a remote jobsite with a slow connection
at the moment. I will post a report later after I download and
test it.
stijnva...@hotmail.com
Looks nice, Altough i'm unable to run the download (dongle missing) .
Where did you find the pricing info ?
Stan
Guy Macon
Content-Transfer-Encoding: 8Bit
http://www.harnware.com/forum/post.asp?method=ReplyQuote&REPLY_ID=123&TOPIC_ID=204&FORUM_ID=31
Which says:
|
|From: HarnWare Manager
|Date: 18/07/2007 : 14:53:49
|Subject: Vista compatibility
|
|Daryl,
|If you can wait until our planned release date of August
|1st we strongly recommend that you install HarnWare V5.4
|with Vista. To upgrade from V4.5 we encourage users to
|attend one days upgrade training but later version
|upgrades are free. We have, however, introduced an
|annual license fee of £250 to help fund support and
|new development work.
|
|V5.3 is only available on CD.
|Regards
|Ken
Dave Pollum
For a project that I worked on years ago, I made simple assembly
drawings for each cable. The drawings were made using a GP drawing
package. I suppose a lite version of Autocad would be used today.
Each cable drawing included a BOM, plus 2-d drawings for each
connector, the length to cut each wire, and where each pin went into
what connector. For ribbon cable/IDC connectors, I even showed how to
fold the ribbon cable, which had needed some 90 degree turns. As a
sanity check, we also made up two sets of cables, one for us and the
other for the assembler. I've also made some cable assemblies in my
home lab, as a sub-contractor. (Shameless plug: if anyone needs
cables assembled, I'm interested.)
-Dave Pollum