All about saving DWG files

AskInga logo

Original Article Date: Nov 23, 2004

If you've ever wondered if you can control MicroStation V8's behaviour when it comes to saving graphical changes to DWG files, this article is for you. Read along and learn.

Barry Bentley once wrote “....we have designed the V8 file format to make it possible to do very fast incremental saves so that the auto-saving is very unobtrusive [when working with V8 design files.] However, the DWG format does not permit that - you have to save the whole file from beginning to end every time. In a large file, that can take an appreciable time, during which MicroStation would be unresponsive.” The following information will help you understand how to set up MicroStation to save changes effectively and with minimum interruption.

Automatically Save Design Changes
When Automatically Save Design Changes is turned on in your workspace preferences, MicroStation will save the graphical changes to the file after 5 minutes or 300 seconds. This time is determined by the configuration variable MS_DWGAUTOSAVE which is described in greater detail below.

During the save operation, MicroStation will pop open a dialog asking if you'd like to save your work. Keep in mind that if you click the OK button, and you just so happen to be in a large DWG file, the save process may take a while during which MicroStation would be unresponsive. The appearance of this dialog is controlled by the configuration variable MS_DWGAUTOSAVE_NODIALOG which is described in greater detail below.

When Automatically Save Design Changes is turned off, MicroStation will not save the changes to the file until the file is closed. Of course, in the event of a power failure or other problem that would cause MicroStation to close unexpectedly, you will loose your work. To reduce this risk, it's strongly recommended to poke on the save icon after doing a measurable amount of work to the file. This icon appears in the Standard tool box as well as on the right side of the status bar. Alternativly, you could also go to File > Save, or just keyin CTRL+S.

The last thing to mention here is that when Automatically Save Design Changes is turned off, you will be asked if you want to save your work when you close the file as described above. This is similar to how other memory-based programs work.

AutoSave Feature
MicroStation V8 2004 Edition has an autosave feature that assists with the saving of DWG files. This feature is controlled by a couple of configuration variables:

MS_DWGAUTOSAVE - Internally, this variable is set to the default value of 300 seconds (5 minutes) and is used when Automatically Save Design Changes is turned on. If you find that 5 minutes to either too long or too short, you can define this variable to better suit your needs. The value to use is the number of seconds between saves with a minimum value of 30 seconds.

Additionally, when this variable is defined you'll notice that Automatically Save Design Changes gets turned on (even if you had it off before defining the variable), and it also becomes grayed out. In summary, when this variable is defined, changes to the file will automatically be saved as per the defined seconds and you will be presented with a dialog asking if you want to save the changes to the file as shown above.

MS_DWGAUTOSAVE_NODIALOG - Since DWG files take longer than DGN files to save, MicroStation displays a dialog box allowing you to defer the auto-save operation. If this variable is set, the dialog is skipped and auto-save occurs automatically.

AskInga Article #226