Abstract: A communication interface 122 for a network having a plurality of nodes 100-108 and a communication link 124,126 (120) connected between predetermined ones of the nodes 100-108 which propagates bus data, includes a first shared communication circuit 128, to be connected in series with the link 124,126, which receives the bus data and passes shared data along the link 124,126, a second shared communication circuit 136,142, connected to one port 129 of the circuit 128, which receives the bus data from the link 124,126 and passes the shared data, and which receives the shared data and couples the shared data onto the link 126, a first unshared communication circuit 144,148, connected to the port 129 of the circuit 128, which receives the bus data from the link 126 and passes the unshared data, and which receives the shared data and couples the unshared data onto the link 126, a second unshared communication circuit 130,134, connected to another port 127 of the circuit 128, which receives the bus data from the li

Abstract: A node configuration system with identical nodes includes a master 10 connected to a plurality of identical servant nodes 12-18 through a shared communication link (or bus) 20 and an unshared communication link (daisy-chain) (28,34,38,44,48). The master 16 assigns a unique identifier to each of the servant nodes 12-18, sequentially and individually, in a clockwise (CW) direction by sending configuration messages on the shared bus and configuration enable signals on the unshared link. The process begins with the master setting its configuration enable signal (CW-Cout port 24) to one and broadcasting a configuration message on the bus 20, which configures the servant node 12. As each servant node is configured, it sets its CW-Cout port to one which enables the next node in the chain to be configured. This process continues until all the servants 12-18 have been configured. In the event of a fault, the master 10 attempts to configure the remaining servant nodes in the counter-clockwise (CCW) direction.

Abstract: A hierarchial elevator control system (FIG. 2) utilizes standard Control Area Network (CAN) hardware and message protocols. A broadcast message format includes priority bits and source address bits in subfields within the standard CAN message identifier field, to separate priority levels from message type information, while maintaining collision avoidance by means of the source addresses. In a unicast message format, message response by individual receiving nodes is accomplished with simple standard CAN hardware filtering by providing, within the standard CAN message identifier field, a multi-bit destination address field to identify a unique receiving node to which the message is directed. In the unicast format, remote transmission requests are identified by a control bit in the standard CAN data field, and responded to utilizing a message-type field that is also in the data field portion of the message.