Workplane Not associated

[wfrst2008]

Hi
Have you ever came across this ?
When I click the workplane tool, sometimes with
Not associated shows up but sometimes no.
Once I choose not associated, for exampe, draw
a line by picking an imported autocad file, the line
will go to certain Z-value that offset from the level plane.
In my case, it is 778mm
Do you know what control this offset ?

thanks for your time

[kathy71046]

That window is so you can pick a workplane by either name, or by picking a line, choosing not associated will leave you with no workplane.

I'm not sure why you would use an autocad file to pick a workplane.

The line you pick will be perpendicular to your workplane, so if you are selecting it in elevation, then you will end up with a level (z distance).

if you are trying to get a sloped plane (like a roof) the best method is to draw a reference plane, and name it, then select by name

[wfrst2008]

Thanks for your prompt reply, Kathy.

I'm sorry that I didn't explain my query clearly.
Actually, I would like to create a swept blend and use
a path which was already drawn in an Acad file.
Normally , you have to choose an active workplane before you
start to pick a path, right ?
In my case , this "not associated" not definitely turned up, this is
the first question.
and the second question is when I choose "not associated" and
pick path ---> select the line in ACAD file, Revit cannot detect
the ACAD entities, so I need to draw a model line first, again, choose "not associated" and pick , the line will be generated
at a certain offset from one of the level planes. So what controls
where this line will be?

I hope my questions are more easier to elaborate this time.

[kathy71046]

I have asked plenty of not properly explained questions ;)

I haven't really done much with swept blends, but something theat may help other more experienced users answer your question...

Are you creating the blend in a family, or in the project?

[wfrst2008]

This is an in-place floor slab with curved egdes on plan while sloping on elevation. Blend swept should be the best choice
to my knowledge.

The problem is not related to the modeling tool, just
a Revit Rule which I do not know as I guess.

Anyway, thank you very much indeed for your caring about
this minor problem.