Nate Holt's Blog

January 28, 2010

Multiple Users on a Single AutoCAD Electrical Project – Q and A

Filed under: Electrical — nateholt @ 6:14 pm

Questions about this subject have popped up in my email recently – multiple times and from multiple sources. Here is a compilation of the typical questions and my emailed responses. Hope this helps explain how it all works! – Nate.

Q1. Is it possible to have multiple users working on the same AutoCAD Electrical project at the same time?  [Nate reply: Yes, but the normal AutoCAD limitation applies… only one user can have a given drawing active for “write” at a time. In other words, multiple users can be working in a common AutoCAD project but they need to be working on different drawings in that project – same limitation as normal AutoCAD.]

Q2.  Okay, but are there any limitations when two or more users work simultaneously in a single project (but on different drawings)? As I saw in the discussion group, the users should/must access the same project database.   [Nate reply: No, each user has his own copy of a project database that is on his local machine. What is common among multiple users working on the same project is the set of AutoCAD dwg files. Let’s say the project name is x:\projects\customer001.wdp and the drawings are on some network drive. Each user who makes this common project an active project will trigger the local copy of AutoCAD Electrical to create a copy of the scratch database file in the local machine’s AutoCAD Electrical USER folder.]

Q3. What is the file name of the local project’s scratch database file and where is it stored? [Nate reply: It’s in the “USER” folder defined for AutoCAD Electrical. You can see the full file name displayed in the Project Manager window as shown here. Highlight the project name in the PM window. The scratch database path and file name is shown in the “Details” window. Programmatically, you can get this path/file name by executing this Lisp function:  (c:wd_mdb_get_proj_scratch_dbnam nil) [Enter].

Q4.  There are some batch operations in AutoCAD Electrical (e.g. reports, update, retag); is there any problem, if more than one user works in the project – because drawings by other users are locked?  [Nate reply: same limitations for regular AutoCAD apply to AutoCAD Electrical. Only one user can be modify a drawing at one time. AutoCAD Electrical will TASK operations that need to be applied to a drawing that is opened by some other user.]

Q5. Is it possible (or is it by default?), that the project database is always up-to-date? That every (logical) change in a drawing is immediately written back to the database? [Nate reply: the database will be kept up-to-date but this is not instant. There may be a delay, and the delay grows longer as the project gets larger. But hopefully the delay is not more than 5-10 seconds under most conditions.]

Q6. Let say I have projects with up to 1.000 pages in one project; is it useful (for performance) to divide the projects in some smaller projects and combine them to a super project (accordingly to an article in your blog)?   [Nate reply: yes, it is good to break the project up into logical sections (when practical) to improve performance… and then have one overall “super” project that you make “active” when complete reports and such are required across all subsections of the project.]

Q7. Okay, in a multi user enviroment, each user has his own scratch database, as you mentioned. But one thing, I don’t understand: if user A places a fuse with tag F1, how does AutoCAD Electrical know, that for user B the tag F1 isn’t anymore available? In a single user environment, I get the message ‚ “Duplicate Component”. [Nate reply:  User “B’s” copy of the scratch database will not know about “F1” until user “A” does a “QSAVE” on the edited drawing. This causes the time/date stamp on the edited drawing to change. User B’s copy of AutoCAD Electrical will see that one of the drawings is “out-of-date”. It will read that drawing and then update user B’s copy of the scratch database. Now user B’s copy of AutoCAD Electrical knows that “F1” fuse tag is no longer available. So, the key is that user A needs to assign the tag but those tags are not visible to other users on the network until user commits his changes (via a QSAVE of the drawing).]

 UPDATE: added Q7



  1. can i open the one drawing with multiple user ?
    please help me
    send me your reply on may email id

    Comment by Abhishek — July 24, 2010 @ 8:31 am

    • The limitation is the same as for AutoCAD. Multiple users can access the same “.dwg” file but only the first person has “Read/Write” access. The other users would see the drawing in AutoCAD “Read only” mode.

      Comment by nateholt — July 24, 2010 @ 8:36 am

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