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:).

Monday, 20 February 2012

Extracting libraries from your design files.

Have you got a schematic and PCB created in CADSTAR 11 onwards but no libraries to enable you to modify them?
If so then you can easily recreate the libraries as CADSTAR keep a local copy of the parts library in the design files themselves. This makes it simple to extract and create a design specific library.

Here is how it works:.....

Monday, 13 February 2012

Using a BOM spreadsheet to quickly add parts into a CADSTAR design.

Recently a colleague has been spending his time reverse engineering an old design that someone only has Gerber's, schematic diagram as PDF and a parts list for so that it can be reworked, modified and bought up to current standards.

At best this is a time consuming task requiring a printout of the schematic, a search of the spreadsheet for a component, copy the part name then paste it into the slide out library search field and then left drag the found part into the schematic, hit escape once then select the symbol properties and change the component name to suit the schematic.  Then join the symbols up with connections etc.

Sunday, 12 February 2012

I have gone mobile!

Just a note to say - I noticed that in the blog setup there was an option for a mobile theme, so I have enabled it to allow the blog to be read better via a mobile.

Now I just need to pull my finger out and make enough posts to warrant you visiting it on your phone :)

Check your dangler shape!

Hey folks, I thought I would share a warning with you about danglers.

The dangler is that little blob that gets left dangling when making a schematic connection and you double click in free space. It is designed to allow you to temporarily leave a connection dangling while you sort out something for it to connect to.

Simply put - Danglers are created when you terminate a connection in space.

I.E. you bring a connection from an IC in one corner of your schematic sheet to the other corner only to discover that you have forgotten to add the part it connects to, you double click and drop a dangler leaving the connection there - saving having to redraw it all while you add your part then continue adding the connection from the dangler.

Apart from junctions, signal references and global signals, a dangler is the only way to leave a connection without it being connected to a symbol terminal. 

So what is the warning?

Well, if you are drawing your schematic on a very fine grid, (I.E. 1th) you have to be extremely accurate connecting to symbol terminals or other connections, if you miss and inadvertently double click then you can leave a dangler instead.
Unfortunately if your dangler is the same shape as a junction then it looks the same and you do not notice that the connections are not actually the same net.

This is actually a mis-connection near the
vertical net and a dangler.

Here the vertical connection has been
pulled to the right to show the dangler.

OMG! you think - why does it let you do this? Well it lets you do this because you are not using a proper grid system and it thinks you are just dropping a dangler.

I have had designs that others have drawn that have had danglers like this and there have been net disconnects which would have made the circuit a failure had I not changed the dangler shape as one of the first things I do in a schematic.

The default shape is a circle, I disagree with this due to the above possiblilities of errors so urge you to read on and change it.

So what is the answer to this?

Well its two fold.
Firstly, do not draw your schematics on a fine (1th) grid, speaking from experience it allows them to look awful, connections are not straight as they do not line up - symbols are all on different levels etc.

Use a decent grid, if your symbols are drawn on a coarse (100th) grid then place them on that, connect to them on a minimum of 25th. (Or whatever your metric version is).

Secondly, and this is the most important bit - Change the shape of the dangler!

Do not have it the same shape as a junction point (circle) make it something obvious like a square.
Use some colour and make them Red. This way they are immediately obvious and can be immediately corrected.

From the file menu, choose Settings\Assignments\Terminal tab - in the Dangler shape box, select it and from the drop down choose square and OK that.

In Colours, select Danglers then Change Colours, select the word Danglers on the left then choose a highlight colour different to your junctions on the right.

Now you can see the difference when you have made this mistake.

Remember to make this change in your templates and symbol library assignments.