Controller redundancy and switching method

Abstract

The invention discloses controller redundancy and a switching method. The method is used for the redundancy switching logic between an industrial controller main machine and a spare machine. Calculation and output synchronization between the main machine and the spare machine is guaranteed, and rapid undisturbed switching is achieved when the main machine fails. A switching circuit is composed of two pairs of GPIO control lines and a 100M Ethernet. Through recognition of low level states, pulse signal states and high level states of IOs, the normal state or the failure state of the opposite end controller main machine or the spare machine is obtained, and the normal state or the failure state of the main machine or the spare machine of an opposite end controller can be obtained in a communication mode when the hardware switching circuit fails, so that arbitration and switching of the main machine and the spare machine are achieved. The design method of state machines is adopted, the operation states of the controller are summarized to be five states that the main machine is normal, the main machine fails, the spare machine is normal, the spare machine fails, and opposite ends are powered off, and the arbitration treatment of the main machine and the spare machine is achieved through matrixes of the state machines. The hardware switching circuit and redundant communication serve as connecting signals between redundancy devices, reliability of redundancy switching control is greatly enhanced, and stable operation of an industrial control system can be effectively guaranteed.

Description

technical field [0001] The invention belongs to the technical field of industrial automatic control, and in particular relates to a distributed control system (DCS) controller redundancy and switching method, and is applicable to various industrial automatic control systems with redundant configurations. Background technique [0002] In the field of industrial automatic control, the cost of equipment downtime due to communication failures and equipment failures is extremely expensive. Hot standby redundancy is one of the most effective technologies to improve system reliability, such as power redundancy, controller redundancy, and network redundancy. , server redundancy, etc. [0003] The hot standby redundancy of the controller is composed of two controllers with exactly the same hardware and engineering configuration. The controllers usually switch in two ways: 1) switching hardware circuits through redundancy; 2) exchanging information through redundant communication chan...

AI Technical Summary

Problems solved by technology

[0004] Among the existing controller redundancy switching technologies, there are three implementation methods that are widely used: 1) Multiplex the Ethernet channel between the active and standby controllers and the monitoring system (HMI) to exchange redundant information. The configuration is relatively simple, but the real-time performance of the active / standby switchover is low. Due to the shared network with the HMI, only a small amount of information can be exchanged between the active and standby machines, and the undisturbed switchover cannot be strictly guaranteed; 2) Use a dedicated redundant communication channel (such as HDLC, 100M Ethernet, etc.), while taking into account the switching and synchronization functions. This method has low real-time performance of active and standby switching, and cannot guarantee non-disruptive switching in the case of fast logic tasks. On the other hand, when the redundant communication channel fails , the system will have dual-master controllers, which will have a fatal impact on system operation; 3) Use a dedicated master-standby switching circuit, such as a synchronous interlock circuit based on FPGA design, etc. The external circuit design is more complicated and the failure rate is higher

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