The use of UML throughout the design process of low-cost distributed control systems is here proposed. In absence of a unique standard for the hardware and the software the only way to proceed is to conduct the control systempsilas design at a high level of abstraction, deferring integration issues to the physical layer implementation phase. The first contribution of the paper is to show how UML can help doing this, by expressing, for example, systempsilas requirements. Moreover it is here discussed the idea of conferring an ldquointelligencerdquo to real objects, making them smart objects by combining new technologies with UML, so that they can cooperate to fulfil the desired tasks in a distributed plant. To illustrate the proposal, a case study is presented.