Elevator Fixture Daisy Chain Network Redundant Paths
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Solution Overview
Problem
Existing elevator communication networks using star-wired Ethernet topology are bulky, expensive, and unreliable due to long wire runs, which increase the risk of damage and require numerous network ports and repeaters, leading to logistical challenges and increased costs.
Innovation Solution
A daisy chain communication network with redundant data paths is implemented, where each fixture is connected to its neighbor or an Ethernet switch, using a process to identify devices and prevent network loops, reducing the amount of Ethernet cabling and the number of required ports.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If star-wired Ethernet topology is used with home run wiring from each fixture to the machine room, then each fixture can be connected reliably, but the amount of cabling and number of network ports required increases significantly
Solution Approach 1:
Multiple fixtures are merged into a single daisy-chain segment that connects to the controller through a single Ethernet cable, rather than each fixture requiring its own separate cable. This combining approach reduces the total quantity of cabling while maintaining reliable communication with all fixtures in the chain.
Solution Approach 2:
The network topology transitions from a two-dimensional star pattern (each fixture independently connected to center) to a one-dimensional linear daisy-chain structure, reducing spatial requirements for cable routing and minimizing the volume of cabling infrastructure needed.
2Reliability
If star-wired Ethernet topology is used with home run wiring, then each fixture has dedicated connection, but the number of Ethernet switch ports required increases
Solution Approach 1:
Multiple fixtures are combined into a single daisy-chain segment that occupies only one network port on the controller, rather than each fixture requiring its own port. This merging reduces the number of ports from 40 to just 2 while maintaining reliable communication with all fixtures.
Solution Approach 2:
A single Ethernet cable and network port serve multiple fixtures simultaneously through the daisy-chain architecture, making the network infrastructure more universal and multi-functional. One port can manage an entire daisy-chain segment containing multiple fixtures.
3Adaptability or versatility
If longer wire runs are used to accommodate larger building sizes, then fixtures can be reached, but cable damage risk and communication reliability decrease
Solution Approach 1:
The network is segmented into multiple daisy-chain segments, each with limited cable lengths. This segmentation allows the system to accommodate large buildings by creating multiple shorter chains rather than requiring single long cable runs, thereby maintaining communication reliability while adapting to larger building sizes.
4Reliability
If more cabling is used for redundant paths, then network reliability improves, but installation complexity and space requirements increase
Solution Approach 1:
The redundant communication paths are merged into the existing daisy-chain structure itself, where each fixture naturally provides two paths to the controller (through its neighbors in the chain). This approach provides network redundancy without requiring separate redundant cabling, thus improving reliability while minimizing installation complexity.
Data Source
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AI summary
A method of interconnecting a daisy chain communication network having a terminal managers and a plurality of managed switches and a plurality of fixtures operable as clients of a client server network. The method also includes transmitting a discovery message to a first fixture and a second fixture, capturing the discovery message in the first fixture and the second fixture, and determining a first head fixture and at least one of a second head fixture and a tail fixture. Furthermore, the method also includes discovering an intermediate fixture based on the first head fixture and the at least one of a second head fixture and a tail fixture, resolving which of the first head fixture and the at least one of a second head fixture and a tail fixture is to be identified as an active head fixture, and establishing the active head fixture and a passive tail fixture.