[Tutor] How to send an array of clusters from python to labview??

[Danny Yoo]

On Mon, 27 Jun 2005, john taylor wrote:

> i am using win32com to call labview from python over COM.  i want to set
> the value of a control element in a VI per SetControlValue(), and the
> control in the VI is an array of cluster, which has the structure
> (integer, integer, string).
>
> >>> aoc = ((2,3,"hello"), (4,5,"world"))
> >>> vi.SetControlValue("array of cluster", aoc)
> Traceback (most recent call last):
> File "<interactive input>", line 1, in ?
> File "<COMObject <unknown>>", line 2, in
> setcontrolvalue
> com_error: (-2147352567, 'Ausnahmefehler
> aufgetreten.', (0, None, None, None, 0, -2147352571),


Hi John,

This seems a bit specific to the Windows platform; you might want to ask
this on Python-win32, especially since it looks like other LabView folks
have been asking questions there too:

    http://mail.python.org/pipermail/python-win32/2005-April/003182.html

The Python-Win32 list is here:

    http://mail.python.org/mailman/listinfo/python-win32

It's not that we don't like answering questions, but that I don't think
many of us here have the expertise to help with COM issues.  The folks at
python-win32, however, should be able to help you.  It will also be useful
to show how you're constructing the labview object 'lv'.


>From a first glance, you meantion that SetControlValue takes in an array
of cluster information.  You've contructed a tuple:

######
aoc = ((2,3,"hello"), (4,5,"world"))
######

and I'm not quite sure if the COM bridge will automatically translate this
into an 'array' that COM likes.


According to the thread on:

    http://aspn.activestate.com/ASPN/Mail/Message/python-list/1556557

and Mark Hammond's reponse:

    http://aspn.activestate.com/ASPN/Mail/Message/python-list/1556557

you might need to build your 'lv' object in a particular way to make sure
the proper type information is maintained.


But again, I don't run Windows: I have no clue what's going on.  *grin*
Ask the win32 list, and someone there should be able to figure out what's
happening.


Best of wishes!