Welcome to the CADSTARguys Blog - Information, hints, tips and my waffle on the CADSTAR Printed Circuit Board design suite.

Please note that all names used are completely fictitious and any thing written is my own personal opinion or knowledge and not related in any way to either my employers or their customers (or Zuken).
Also this is not a replacement for proper Maintenence/support and you should read the help files before asking anything techy:).

Saturday, 13 November 2010

Assignments - what are they then?

So what are the "Assignments" in CADSTAR for?

Basically assignments is the term given to they settings for all the route, line, pads, text, copper, via codes amongst others. You assign values to them.

They are all kept within the assignments in CADSTAR, it is worth noting that CADSTAR keeps its assignments in each individual design file, within each schematic and documentation symbol and PCB library also the default files used for new design files.

So essentially they are configured in many places, so which set is the master set?

Nether really, as you are able to change them specifically for each individual design however it is always advised that your library assignments should be treated as the master set and they should overrule any others.
When creating your assignments you should always try and name them as descriptive as you can for their purpose, for instance - for the outlines on symbols call the assignment "Symbol Outline", for the text code used for Pin Labels then call the assignment "Pin Label Text".

Create an assignment for every type of item used in CADSTAR so that changing a single assignment does not mess up other items.

I.E. if you used (the rather nondescript named) "Line 10" for both symbol outlines, figures and document symbol outlines then a change from 10 to 20 just to make your border look thicker will make a mess of all your symbols. In my opinion it is much better to have a greater control of your items by giving them individual assignments.

I would also suggest that you document your assignment names, define exactly what they are to be used for and when.

That way you are able to copy and paste from an electronic document the names of the assignments so that you do not create 2 similar named assignments but with an extra space or typo in, as it it very hard to remove an assignment once used in your library.

In Settings\Assignments you have separate tabs for each type of assignment, there are too many to describe in one post so I wont go into them that deeply, suffice to say that you should learn what each one is for, create and stick to a theme for your assignments.

As a note - I have said that you are able to change assignments in each design file, this means that for instance you can select a pad, choose it's properties, go to the assignment for that pad and change it's dimensions. Be extremely careful doing this because if you download the assignments or reload the component you are likely to revert the assignment to how it originally was. There are better ways to change pads.

Finally once you have figured out what assignments you want to use and why you want to use them it is also sensible to document them. They can be copy and pasted into other documents to aid this.

4 comments:

Anonymous said...

Hi,

very nice blog. One question. What are the "better ways to change pads"? I want to change some names and there are also a view corrections at existing pads necessary. Is there a "main file" where I can manage this. The creation of new correct pad with new names has the disadvantage, that the wrong pads are still available for all new components.

Regards,

Günter

The CADSTAR Guy's Blog. said...

Hello Gunter, thank yoiu for the comment.

But why would you be changing the pad code values?
Perhaps because you got it wrong first time? or because manufacturing has come up with a reason to make it differently etc
Either are very comon situatiuons.

If, in a design you have a pad assignment used on a component and you want to change the pad assignment values used by it then rather than change the values of that pad code I think it would be better to create a new pad code all together.

Whatever the reason and depending on the situation it may be even better to change the component in the component library - perhaps make an alternative if it is used elsewhere and the existing pad code is OK for those other designs. Essentially - f you change the values of a pad code in your component library and that pad code is used by multiple components then you will be altering all those components. There will be situations where this is desired and situations where it is not - this is for the user to decide.

There is no one place that the pad code can be changed, the library assignments would be considered the master set, however each design can be modified to be different. This makes it very flexible however the drawback is that a download of assignments will reset them to match the library so this needs to be taken into consideration when changing any assignment values in a design.

Anonymous said...

Hello,

thank you very much for your quick response. You are right, in the most cases it is better to generate a new pad code. But like you mentioned before, there are a view reasons, where a change is the more desired way, especially when there is a mistake in a new pad.

I working with CADSTAR since a view years and never find a solution for this issue.....till yesterday, after my question. :-)

When you are in the library editor working on a new component, you can't change an existing pad code on the Assignments button. But you can change it, when there is no component open. Only click on Libraries, PCB Components and then on Assignments. There you have the possibility to change pads.But like mentioned before, be careful.

Sometimes, it's so easy...

Thank you very much for your answer and your help. Sorry for the stupid question. I'm sure that everyone knows this solution, beside me. :-)

Regards,

Günther

Anonymous said...

Hello Günther,

Thanks a lot for the tip! I have also wasted some time trying to find out how to update my "master" library assignments, but my changes always seemed to disappear. Very annoying! Editing the assignments from Libraries --> PCB Components --> Assignments does the trick!

Also, thanks to the CADStar Guy! Your blog is so much more useful than the CADStar documentation...

Regards,
Torie

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