RS485 communication interface automatic baud rate and communication address detection method
A technology of RS485 and communication port, which is applied in the field of automatic baud rate and communication address detection of RS485 communication port, which can solve the problems of increasing hardware overhead and cost, difficulty of communication connection, adding detection circuit, etc., so as to avoid errors and avoid extra expenses Effect
Inactive Publication Date: 2014-07-09
上海开通数控有限公司
View PDF3 Cites 16 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Such a serious impact on the use of the RS485 communication port makes it difficult to use the RS485 communication port to establish a communication link between the master and the slave
Others also increase dedicated detection circuits, increasing hardware overhead and cost
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 moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0014] Such as figure 1 Shown, the RS485 communication port automatic baud rate of the present invention and communication address detection method comprise the steps:
[0015] Step 1. When the master is connected to a single slave, the master sends a fixed handshake protocol in the broadcast mode of the RS485 communication port, once for each baud rate, until a slave responds, and the slave responds at the baud rate Establish a communication link with the station number;
[0016] Step 2. When the master is connected to multiple slaves, the master sends a handshake protocol to the address of each slave, and each slave starts to decode after receiving the handshake protocol. When it is confirmed that it is the handshake protocol sent by the master to the slave , the slave sends a response to the master, telling the master the station number of the slave, if the handshake protocol sent by the master is not to access the slave, the slave will not respond;
[0017] Step 3. If th...
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
Login to View More Abstract
The invention discloses an RS485 communication interface automatic baud rate and communication address detection method. The method includes the steps that when a mainframe is connected with a single slave, the mainframe sends a fixed handshake protocol in a broadcast mode at one baud rate each time till the slave resounds so as to set up communication connection; when the mainframe is connected with multiple slaves, the mainframe sends a handshake protocol to each slave address, when the slave conducts decoding and determines that the handshake protocol is sent to the slave, the salve responds to a station number given by the mainframe, and when the slave conducts decoding and determines that the handshake protocol is not sent to the slave, the slave does not respond; when the mainframe receives the response from the slave, decoding is conducted, communication connection is set up, the baud rate and the station number which are in communication with the slave are recorded, and next circulation is started if no response is received. According to the method, the automatic baud rate and the communication address of an RS485 port can be accurately detected, communication connection between the mainframe and the slaves can be conveniently achieved, extra expenses of hardware are omitted, and errors caused by interference during communication are avoided as well.
Description
technical field [0001] The invention relates to an automatic baud rate and communication address detection method of an RS485 communication port. Background technique [0002] RS485 communication port is a widely used data communication bus, often used between the centralized control hub and the decentralized control unit. If the signal transmission distance or the number of nodes on the line exceeds the rated parameters of the chip, how to ensure the accurate transmission of the signal on the line is a very important task for the communication system. RS485 communication port adopts differential signal negative logic, +2V~+6V means "0", -6V~-2V means "1". RS485 has two types of wiring, two-wire system and four-wire system. The four-wire system is a full-duplex communication mode, and the two-wire system is a half-duplex communication mode. In the RS485 communication network, the master-slave communication mode is generally adopted, that is, one master has multiple slaves....
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
Login to View More Patent Type & Authority Applications(China)
IPC IPC(8): H04L12/26H04L12/40H04L29/06
Inventor 肖智明
Owner 上海开通数控有限公司