Optical fiber CAN bus hub and networking method thereof

Abstract

The invention discloses a networking method of an optical fiber control area network (CAN) bus hub. A main hub of an optical fiber CAN bus with n optical fiber interfaces and a local twisted pair electrical interface extension circuit and n twisted pair CAN sub-networks for connecting the main hub with n optical nodes, n secondary hubs or n remote electric interface extension devices are connected with a local twisted pair CAN sub-network to form a network; signals are transmitted, received and separated by using the optical fiber CAN bus hub which realizes a wired and function through a complex programmable logic device (CPLD) and is provided with a plurality of optical interfaces and a twisted pair electric interface extension circuit, double CAN transceivers and two twisted pairs, so self-excitation blocking communication caused by a signal transmission loop is avoided; and the optical nodes, the local twisted pair CAN bus sub-network and the remote twisted pair CAN bus sub-network are connected by using the optical fiber CAN bus hub, the optical fiber pair and the remote electric interface extension device to form a high-network-speed wide area networking scheme.

Description

technical field [0001] The invention belongs to a CAN bus network, in particular to a CAN bus hub whose transmission medium is an optical fiber and a wide-area high-speed networking method based on the hub for connecting an optical fiber CAN node and a twisted-pair CAN bus subnet together. Background technique [0002] CAN (Control Area Network) bus is a field bus network that uses a non-destructive bit contention mechanism to realize serial multi-master communication. CAN bus has the advantages of strong anti-interference ability, short message, good real-time performance and low networking cost. It is especially suitable for fields such as industrial automation sites and auto parts control with harsh environments, large electromagnetic radiation, and high reliability requirements. The most commonly used transmission medium of the CAN bus is a twisted pair, and the highest rate achievable on this medium is 1Mbps. In actual use, the available communication rate of the twis...

AI Technical Summary

Problems solved by technology

Among them: (1) the ring optical fiber CAN bus network scheme allows a very limited number of nodes (only optical fiber nodes) in the access ring, and with the increase of the number of access nodes, the communication rate drops sharply; (2 ) The optical fiber CAN bus self-healing ring network scheme also has similar problems; (3) The dual-star optical fiber CAN bus scheme allows more nodes to be connected, but like the previous two schemes, there is a signal transmission loop self-excitation that causes network congestion and inconvenient interfacing with twisted pair CAN bus subnets

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