Graphics Programs Reference
In-Depth Information
Adding Parameters and Constraints
The key to having equipment families that are usable in the early stages of
yourdesignsistohavefamiliesthatareeasilymodifiedtomeetthedemands
of frequent changes to your project model. Using parameters gives you the
flexibility to change not only the size of equipment but also the values of
connectors.
Three simple dimensions can define most equipment: length, width, and
height. By using these parametrically, you can be confident that your
equipment families occupy the space required for them in the model, even
if they do not look exactly like the object they represent. Be consistent with
your use of these parameters and particularly the naming convention you
use. They do not need to be shared parameters unless the information is
to be included in schedules. However, you could create them as shared
parameters for consistent naming. Because there may be other dimensions
in your families, it is best to give these parameters a descriptive name, such
as Unit Length or Equipment Width, to distinguish them as the overall size.
Of course, having these parameters in your families is not enough; you need
to have the family geometry associated with them.
MEP equipment schedules vary in size and information, not only from one
company to another but even in the same company, depending on the
project standards or client demands. Mechanical equipment schedules are
particularly difficult to manage without the proper use of parameters in
your equipment families. The use of shared parameters is necessary for
scheduling the systems information required from equipment schedules.
The problem is that all mechanical equipment families are in one category.
To avoid having families with unnecessary parameters, it may be best to
apply your shared parameters directly in the equipment families instead
of using project parameters. That way, you can be sure that you have only
the parameters required for the scheduling of the specific families in your
mechanical equipment schedules.
Connectors have parameters that you may need to change based on the
performance of your engineering systems. Creating parameters in your
families with which the connector parameters can be associated allows you
tochangetheconnectorvalueswithouthavingtoopen,edit,andreloadyour
families. The main thing to remember when creating these parameters is
thattheymustmatchtheunits oftheconnector parameter inorderforthem
