Just to re-iterate Kells's comment -
"you don't want to try to access the dmd from in a modeler plugin as only madness lies this way".
I did this using the following in a modeler plugin in my ZenPack:
# Don't even think of uncommenting these 2 lines - here lies madness!!!!
#from Products.ZenUtils.ZenScriptBase import ZenScriptBase
#dmd = ZenScriptBase(connect=True, noopts=True).dmd
Everything appeared to be OK and the ZenPack worked fine, but......
The standard modelling of processes stopped working - just for processes with in a process suborganizer - top-level processes worked fine. Needless to say, we didn't immediately spot this issue. Removing the lines resolved the issue immediately. There may have been other weirdos that we never spotted.
So.....
"you don't want to try to access the dmd from in a modeler plugin as only madness lies this way".
Cheers,
Jane