If you are a new user of an ASTi DACS or desire a simple example to use as a base upon which to build an application specific model, then the sample communication model supplied as part of the ASTi Model Builder Utilities files is a good place to start. The following text, diagrams, and model file itself, demonstrate some of the basic concepts used in the Model Builder software. Full details of the objects used to construct the model are found in the Model Builder Reference Manual. Please note though that this document is not a Model Builder Tutorial, nor a substitute for a Model Builder training course. The level of detail presented here is intentionally limited, such that the key points may be brought out.