485 bus system and asynchronous half-duplex communication method thereof

A half-duplex communication and bus system technology, applied in the field of transmission control, can solve the problems of low communication efficiency and achieve the effects of strong adaptability, high signal-to-noise ratio, and improved communication quality

Active Publication Date: 2012-07-04
HANGZHOU HIKVISION SYST TECH
View PDF5 Cites 33 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The inventors of the present invention have found that the existing RS485 bus system asynchronous half-duplex commun

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • 485 bus system and asynchronous half-duplex communication method thereof
  • 485 bus system and asynchronous half-duplex communication method thereof
  • 485 bus system and asynchronous half-duplex communication method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0030] In the following description, many technical details are proposed for the reader to better understand this application. However, those of ordinary skill in the art can understand that even without these technical details and various changes and modifications based on the following embodiments, the technical solutions required by the claims of this application can be implemented.

[0031] In order to make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0032] The first embodiment of the present invention relates to an asynchronous half-duplex communication method of a 485 bus system. figure 2 It is a schematic flow diagram of the asynchronous half-duplex communication method of the 485 bus system.

[0033] The 485 bus system includes: at least two devices connected by the 485 bus, each device is provided with t...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to the field of transmission control and discloses a 485 bus system and an asynchronous half-duplex communication method thereof. 485-bus half-duplex communication is realized by fewest cables, all devices with mutual data transmission are connected equivalently without principal and subordinate relation, and any device can send data to any other device. The 485 bus system comprises a plurality of devices connected by 485 buses, wherein each device is provided with three signal interfaces, two signal interfaces are a pair of 485-bus data transmission differential signal interfaces, the other signal interface is a collision detection signal interface, and the same signal interfaces of all the devices are mutually connected by wires; the asynchronous half-duplex communication method comprises the following steps of: when the devices need to send data, detecting the state of collision detection signals; if detecting to be in a busy state, waiting till to be in an idle state; if detecting to be in the idle state, sending data after setting the collision detection signals in the self collision detection signal interfaces of the devices to be in a busy state.

Description

Technical field [0001] The invention relates to the field of transmission control, in particular to a 485 bus communication technology. Background technique [0002] In the RS485 communication network, the master-slave communication method is generally adopted, that is, a master with multiple slaves, or a master with multiple slaves, each action is initiated by the master, and the slaves are executed after distinguishing by address The corresponding action. [0003] The RS485 communication mode is usually asynchronous half-duplex mode, the so-called half-duplex mode, that is, the working mode in which information can be sent in two directions between two devices, but not at the same time. The so-called asynchronous communication means that the asynchronous two parties do not need a common clock, that is, the receiver does not know when the sending device will send it, and there is information in the sent data that prompts the receiver to start receiving, such as a start bit and a ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): H04L5/14
Inventor 刘念汪发祥孙旷野
Owner HANGZHOU HIKVISION SYST TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap