Otis Elevator Company

Bhargavender P Upender

David C Brajczewski

Alexander G Dean

Stephen A Hatzirallis

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.

Automatic node configuration with identical nodes

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.

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Middletown, CT, United States of America

Bhargavender P Upender