485 communication automatic switching circuit and control method

Abstract

The invention discloses a 485 communication automatic switching circuit and a control method. The 485 communication automatic switching circuit comprises a connector, a 485 communication module, and arelay switching circuit, wherein the 485 communication module is electrically connected with the connector; and the relay switching circuit is connected between the 485 communication module and the connector and can switch a communication loop between the 485 communication module and the connector. The 485 communication automatic switching circuit provided by the invention can automatically identify the communication condition of indoor and outdoor units, does not need to change the wiring mode when judging that wiring errors occur between the 485 communication module and the butt joint control panel, and automatically controls the relay switching circuit to act, so as to realize automatic switching of the 485 communication module and the butt joint control panel. Therefore, the communication loop between the 485 communication module and the connector can be automatically switched, the operation is simple and convenient, the relay is equivalent to a wire, the problem of signal delay is avoided, and the use experience of a user is better.

Description

technical field [0001] The invention relates to the technical field of 485 communication circuits, in particular to a 485 communication automatic switching circuit and a control method. Background technique [0002] At present, the indoor and outdoor units of commercial air conditioners generally use the 485 communication method. During the engineering installation, the 485 communication line AB is often reversed, resulting in poor communication. However, most of the existing 485 communication circuits do not have automatic reverse. Function, if the engineering installation wiring is wrong, it will lead to poor communication and failure to start the machine. The installer needs to disassemble the machine again to check the cause of the failure, and then adjust the wiring sequence, wasting man-hours, increasing the difficulty of construction, and easily causing customer complaints. [0003] The Chinese patent application number 201320882538.0 discloses an automatic identifica...

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Problems solved by technology

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a 485 communication automatic switching circuit, which can automatically identify the communication status of the indoor and outdoor units, and automatically control the relay switching circuit when there is a wiring error Switch the communication loop between the 485 communication module and the connector so that the communication remains normal, the operation is simple and convenient, the man-hour is less, and the operation difficulty is low, and a relay is used to control the switch between the 485 communication module and the connector The communication circuit between the relays is equivalent to the wire, there will be no signal delay problem, and the user experience is better

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