sdi mode

[JohnnyTheAnt]

hi,

1) Does acade ship with SDI set to 0 or 1 by default?

2) What is autodesks recommendation when using acade2010 regarding this?

3) Is it advisable to have multiple sheets open on a drawing especially if they are quite big?

4) Are there any advantages

[dougmcalexander · Accepted solution]

Below is an excerpt from one of the handouts I provide for students who attend my training seminars.  It is made available for this forum only and must not be copied or shared via e-mail, or any other written form of communciation.

AUTOCAD ELECTRICAL ships with SDI set to zero, that is SDI not enabled.  Single Document Interface forces AUTOCAD ELECTRICAL to close one drawing before opening another.  If you click on another drawing in the Project Manager you will be prompted to save or discard changes to the open drawing.  If you change to the next drawing by using the Previous or Next Drawing arrows, AUTOCAD ELECTRICAL will automatically save the edits to the open drawing before opening the next one.  To enable SDI mode you must close down to only one open drawing and type SDI at the command line.  Enter the number 1 and press enter.  Number 1 means yes to SDI mode.  AUTOCAD ELECTRICAL has traditionally functioned slightly faster when in SDI mode. 

SDI mode was the original default state until Autodesk introduced MDI mode for the AutoCAD drafting engine.  The thought of having Multiple Document Interface capability with a relational database may seem dangerous, since the data is normally written to the database when a drawing is saved.  How does the software process changes made on one drawing that might affect another open drawing, even though the drawing being edited has not yet been saved?  Shouldn’t you save the drawing first so the data is written permanently to the database prior to allowing the software to change another drawing?  I mean, what if you aren’t sure about some of the edits you made?  Well, the developers have worked very hard to allow AUTOCAD ELECTRICAL to process based upon the temporary state of all open drawings and yet reconcile all against one another once they are all saved.  It’s magic, most of the time.

Do I believe I have noticed some "hiccups" with this?  Yes I believe I have, but it has improved greatly in the past couple of releases.  The developers tell me that MDI mode (SDI=0) is here to stay because it is what the users of standard "Vanilla" AutoCAD have become accustomed to.  Of course I argue that customers moving from plain AutoCAD to Electrical need to realize that they just left a drafting program and stepped up to a relational database that just so happens to use a drafting engine for user input.  You can make "dumb" AutoCAD do anything you desire, right or wrong!  But Electrical plays by certain rules to ensure data integrity.  As users we must make the mental shift and not try to force Electrical into acting like a dumb drafting tool.

I personally prefer SDI mode because it seems to me that the data can be handled more efficiently when only one drawing at a time has to be loaded into RAM and processed by the data management portion of the software.  But I especially prefer SDI mode for a network environment where multiple designers are accessing drawings within the same project.  This prevents any one designer from having more than one drawing open at a time and reduces the number of proverbial "curve balls" thrown at the data manager.  It can be a hassle when one person has 5 drawings open, not even thinking about it, and it locks you out of a project-wide edit that you needed to make against one or more of those drawings.  But also bear in mind that the project database is more or less a temporary file that resides in the User subfolder of each user's local disk drive.  This means that the data manager must process the changes you are making to your open drawing(s) as well as reconciling changes made by other users to other drawings.  It messes with your mind to think how AutoCAD Electrical can do this, but thankfully it gets better and better at it with each release.

In summation, I prefer SDI mode when networked.  There is less chance for data loss or corruption and faster project-wide processing.  If I am operating local only I may prefer using MDI mode.  I do a lot of symbol/block editing by simply opening the raw block file itself.  It's nice to be able to edit my block on a separate page while I have the project page open where it is used.  I then save my block and use the Update Block tool.  Note: Even in SDI mode, I can accomplish this by opening another session of AUTOCAD ELECTRICAL and using it for block editing.

The choice of SDI=0 or SDI=1 must be made by each user according to their specific situation.  Experiment with both modes and see which best fits your needs.

Copyright 2010 Douglas R. McAlexander

[JohnnyTheAnt]

doug,

Many thanks for this reply. You have confirmed my worries and we are networked as well. I used aceri's electrical designer for 12 years and sdi mode was default set to 1 and this helped immensely, i too was worried about data corruption.

SDI = 1 it is doug 🙂

[dougmcalexander]

Hi Johnny! You may run into an anomaly from time to time in SDI mode. Imagine how difficult it must be for the programmers to check every new feature in both modes. An each new release must be checked in both modes. So some task that works perfectly in MDI may exhibit an issue when in SDI. It's a lot for Autodesk to manage.. If they can get the speed we need and maintain the data reliably in MDI that will be my preferred mode. Version 2011 is much improved with respect to both speed and data management.

[TonyLeggieri3279]

We have run into just such an anomaly...

We have a user (using Civil3D 2009 on Windows XP) that wishes to be in SDI, but everytime he opens a drawing while SDI is set to 1, his OSNAP markers and magnets turn off in the OPTIONS-DRAFTING tab.  When SDI is set to 0, it holds no problem. 

I tried to replicate this on my machine but it does not act the same.  Any ideas?

It may not be a big deal as we are upgrade to Windows 7 and Civil3D 2011 this coming Labor Day weekend (so about 2 more weeks).

Thanks,

Tony

[kevin]

Does effect opening mutliple sheets in the sheet set manager. I have notice that some of my machine can and some can't. All machines are running AutoCAD 2012

[kevin]

Sorry that last post was poorly written. Does this have any affect on how the sheet set manager opens drawings? On some of our machines we can open multiple sheets using the sheet set manager and on other we have to close the open drawing to open a new one.

[sfcbatch94]

Hi Doug,

Thanks a lot, Youre the man.