Multi-master lossless bus competition technology

Abstract

The invention discloses a multi-master lossless bus competition technology, belongs to the technical field of communication engineering and control engineering, and relates to a field bus use right arbitration technology. When a plurality of devices are connected to run through a bus, each device can serve as a device for actively sending information through the multi-master lossless bus competition technology, and the situation that the devices obtain the right to use the bus in a request-response master-slave mode is not needed; when the devices send the information at the same time, information sending conflict is formed by the devices, the devices compete for the right to use the bus, the device which wins the competition obtains the right to use the bus, and continues to send data, the data sent in the process of the competition are still valid, namely, loss of data sent by the device which wins the competition for the bus is not caused, and the speed of data sending is increased; the devices which fail in the competition for the bus stop sending data, and wait for participation in the next competition for the right to use the bus. The multi-master lossless bus competition technology can be used for field buses for synchronous communication, and can also be used for field buses for asynchronous communication.

Description

technical field [0001] The invention relates to a field bus usage right arbitration technology. When multiple devices are connected through the field bus, through the multi-master lossless bus competition technology, each device can become a device that actively sends information, without the need to obtain the right to use the field bus through the master-slave method of request response; if in the same If there are multiple devices sending information at the same time at any time, multiple devices will generate information transmission conflicts and start competition for the right to use the field bus. The device that wins the competition will obtain the right to use the field bus and continue to send information, while sending The information is still valid, that is, the device that wins the fieldbus competition has no loss in sending information, which speeds up the information sending speed; while the device that loses the fieldbus competition stops sending information, w...

AI Technical Summary

Problems solved by technology

According to the different control capabilities of the devices connected to the field bus to the field bus, it can be divided into master-slave mode and multi-master mode. In the master-slave mode, one of the devices is the master device, and the other devices are slave devices. The slave device is selected to send and receive information by means of commands, and the information needs to be exchanged between the slave devices and also needs to be transferred by the master device. The communication efficiency of the master-slave field bus communication method is low, and the real-time performance of the slave device is not high.

In the multi-master mode, each device can actively send information, and each device has the opportunity to send and obtain information in real time; but in the multi-master fieldbus communication mode, if two or more devices send information at the same time , then there is the fieldbus conflict problem; in the method for solving bus conflict of existing multi-master mode fieldbus, one is conflict retransmission, once detects fieldbus conflict, then retransmits, if retransmission occurs fieldbus conflict again, Just resend until the sending is successful or an error is reported; the biggest problem of conflict resending is that the data sent in the competition for the right to use the fieldbus is invalid data and must be resent, which wastes fieldbus resources and reduces the utilization efficiency of the fieldbus , and brings uncertainty to the real-time performance of the equipment. The second is to control the use of the field bus through the token, so as to avoid the conflict of the use of the field bus in the multi-master mode. The main disadvantage is that special node monitoring and management commands are required. Once the token is lost, the entire field bus cannot work. The third is the bit-by-bit arbitration technology used by the CAN bus. This bit-by-bit arbitration technology is a full-frame arbitration comparison technology, including the judgment of identifiers and error checks, etc. , That is to say, this technology of CAN bus is tightly coupled with CAN bus protocol, and is implemented by CAN dedicated chip. This bit-by-bit arbitration technology is difficult to use on other buses. At the same time, the bit-by-bit arbitration technology of CAN bus Used in synchronous communication bus, not yet used in asynchronous communication bus