A combined interface of rs232 and rs485

Abstract

The invention discloses an RS232 and RS485 combined interface which comprises an interface and external input protection module, a pressure difference comparison analysis and RS485 protection module,an RS232 and RS485 main circuit and TTL isolation conversion module, a power supply module and a MCU control unit, wherein the interface and external input protection module is used for providing bothRS232 and RS485 modes of interfaces and suppressing an overvoltage signal and an overcurrent signal from entering a post circuit; the pressure difference comparison analysis and RS485 protection module is used for controlling on-off of an RS485 circuit according to an output of a voltage comparator so as to implement protection on the RS485 circuit; the RS232 and RS485 main circuit and TTL isolation conversion module is used for carrying out signal communication of an RS232 main circuit and an RS485 circuit and introducing an interference signal and an abnormal voltage current signal for external communication; the power supply module is used for providing a 5V isolation power supply for the RS232 main circuit and the RS485 main circuit; and the MCU control unit is in communication connection with the RS232 and RS485 main circuit and TTL isolation conversion module and is used for transceiving a post control instruction. According to the invention, the defects in the prior art can beimproved, compatible communication of the RS232 and RS485 interfaces is implemented, problems of program design and hardware incompatibility are greatly simplified, and the RS232 and RS485 combined interface is beneficial to better maintenance and communication interconnection of equipment.

Description

technical field [0001] The invention relates to a communication interface, in particular to a combined RS232 and RS485 interface. Background technique [0002] With the acceleration of industrialization and information level, various electronic communication devices rely on RS232 and RS485 interfaces more and more widely, as the two most widely used interface standards of RS232 and RS485. Among them, RS232 is full-duplex, but the transmission distance is short and easy to be interfered, and it is a single-point communication mode. It is replaced by RS485 communication interface, but RS485 is a half-duplex transmission mode, forming the two most commonly used RS232 and RS485. The existence of communication mode. Therefore, developing a combined interface that can meet the requirements of RS232 communication and be compatible with RS485 interface has become a problem to be solved urgently in this field. Contents of the invention [0003] The technical problem to be solved ...

AI Technical Summary

Problems solved by technology

Among them, RS232 is full-duplex, but the transmission distance is short and easy to be interfered, and it is a single-point communication mode. It is replaced by RS485 communication interface, but RS485 is a half-duplex transmission mode, forming the two most commonly used RS232 and RS485. The existence of communication mode

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