RS232 communication system supporting multipoint long-distance communication

Abstract

The present invention provides an RS232 communication system supporting multipoint long-distance communication. The RS232 serial communication system comprises a master device and at least one slave device which are connected with an RS232 serial differential bus. In the RS232 serial communication system, a loopback control module controls the bus, an output control module controls an accessed device, a conflict detection module detects a bus conflict, a carrier monitoring module contends the bus control right, and an interface conversion module enables the signal anti-interference capability to be enhanced and a communication distance to be increased. By the mutual cooperation of the loopback control module, the output control module, the conflict detection module and the carrier monitoring module, a half-duplex communication mode and a full duplex communication mode can be supported, and the multipoint-to-multipoint communication can be realized.

Description

technical field [0001] The invention relates to the technical field of serial communication, in particular to an RS232 communication system supporting multi-point long-distance communication. Background technique [0002] RS232 is an interface technology standard for serial binary data exchange between data communication equipment (DCE) and data terminal equipment (DTE) developed by the Electronics Industries Association (EIA). The standard defines 25 signals and corresponding references. foot. In actual use, at least only three signal lines of sending data (TXD), receiving data (RXD) and ground (GND) need to be interconnected to communicate. Because the RS232 interface is simple, convenient and low in cost, it has been widely used. [0003] At present, this standard has been integrated into many microprocessors, embedded processors, DSPs, and CPUs, and many high-performance processors also integrate RS232 interfaces. Devices using these processors often use RS232 as the ...

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Problems solved by technology

[0004] However, there are still many problems in this standard: first, the interface signal is a single-ended signal, which has problems such as common ground noise and common mode interference, weak anti-interference ability, short communication distance, and low rate; second, it can only realize Point-to-point communication cannot realize multipoint-to-multipoint communication. For example, when different boards, different modules, or even different racks and devices need to realize multipoint intercommunication, the integrated RS232 on the processor cannot be fully utilized. Interface, only other interfaces can be used, which makes the selection of processor and communication interface more difficult, and software control and programming are more complicated; third, the standard regulates the electrical standard of the interface, but does not standardize the detection standard of the bus, and has no self-test function. Unable to tell if the bus is faulty

[0005] The above problems are inherent in the RS232 standard, which greatly limits its ability to communicate between computers, boards, modules, and different devices

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