A passive optical splitter rs-485 optical fiber bus multi-port terminal

Abstract

The invention discloses a multi-port terminal of a passive beam splitting RS-485 optical fiber bus. The multi-port terminal is characterized in that the two ends of the multi-port terminal are connected with passive RS-485 optical network local sides of the passive beam splitting RS-485 optical fiber bus and user terminal devices, the multi-port terminal comprises a power supply module, a bus arbitration processor, a plurality of optical conversion modules, a plurality of high-speed optical couplers, multiple RS-485 interface units, two RS-485 cascading interface circuits, two optical fiber cascading interface circuits, multiple routes of RS-485 drive chips, multiple three-stage lightning protection circuits and an optical fiber uplink port circuit, the optical conversion modules, the two RS-485 cascading interface circuits and the high-speed optical couplers are connected with the bus arbitration processor, the optical uplink port circuit and two optical fiber cascading interfaces are connected with the optical conversion modules, and the RS-485 drive chips are connected with the high-speed optical couplers and the three-stage lightning prevention circuits.

Description

technical field [0001] The invention relates to the field of industrial manufacturing, in particular to a passive light splitting RS-485 optical fiber bus multi-port terminal. Background technique [0002] Smart meters developed with the maturity of single-chip microcomputer technology in the early 1980s, and now the world's meter market is basically monopolized by smart meters. The reason is the need for enterprise informatization. One of the necessary conditions for enterprises to select instruments is to have a network communication interface. Initially, the data analog signal output is simple process quantity, and later the instrument interface is RS-232 interface, which can realize point-to-point communication, but this method cannot realize the networking function. Then came RS-485 to solve this problem. [0003] RS-485 uses differential signal negative logic, -2V~-6V means "0", +2V~+6V means "1". RS-485 has two kinds of wiring, two-wire system and four-wire system....

AI Technical Summary

Problems solved by technology

As the transmission distance increases, the communication rate will drop sharply, which cannot guarantee the high-speed and long-distance communication requirements

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