Abstract: A system for controlling the operation of a laboratory with a fume hood having a sash. The system includes an intelligent occupancy monitor mechanism. The system includes an intelligent sash closure mechanism. The producing mechanism and the controlling mechanism form a fully distributed intelligent non-hierarchical architecture. The system includes a network to which the producing mechanism and the controlling mechanism are connected to communicate with each other. A method for controlling air flow in a fume hood.

Abstract: The present invention pertains to a system for transmitting data. The system comprises a network on which free topology transmission of data occurs. The system comprises a first node. The system comprises a second node. The system comprises a shared free topology modem connected to the network and the first and second nodes for transmitting signals from the first and second nodes. The present invention pertains to a method for transmitting data. The method comprises the steps of transmitting data from a first node on a balanced line two-wire differential network to a free topology modem. Next there is the step of transmitting the data from the first node to the free topology network on which free topology transmission of data occurs with the free topology modem. Then there is the step of transmitting data from a second node on the balanced line two-wire differential network to the free topology transceiver.