Process Control Program Switchover for Zero-Downtime Updates
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Solution Overview
Problem
Existing process control systems face challenges in updating operating systems and programs without stopping operations, especially in industrial settings where downtime is costly and risky, as they require complex analysis and processing to maintain continuous operation and safety.
Innovation Solution
A method that pauses non-update target programs, transfers their context, updates the update target program, and then resumes both, allowing for simple and timely updates without stopping the process control system, using a dual-apparatus setup with program update managers to manage the context transfer and initialization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the process control system is stopped to update the program, then the update can be performed completely, but the system downtime increases and productivity is reduced
Solution Approach 1:
The system is divided into a first process control apparatus (active) and a second process control apparatus (standby). The update operation is segmented so that it can be performed on the standby apparatus without affecting the active apparatus, allowing updates to be applied in discrete, isolated steps.
Solution Approach 2:
The update target program is updated in advance on the standby process control apparatus before the standby role is activated. This preliminary action ensures that when the switch occurs, the updated program is already prepared and can be immediately activated without causing system downtime.
2Loss of time
If the program is updated quickly without complex analysis, then the update time is reduced, but the risk of errors and system instability increases
Solution Approach 1:
The standby process control apparatus serves as a cushion or backup that can be prepared in advance with the updated program. If the update on the standby apparatus succeeds, it can be switched to become the active apparatus, ensuring system continuity. This prior cushioning reduces both update time and risk.
Solution Approach 2:
The operational context data from the active process control apparatus is copied to the standby apparatus before the switch. This copying ensures that the standby apparatus inherits the current system state, allowing for a seamless transition while maintaining system reliability during the update process.
3Adaptability or versatility
If the system uses a universal device with open specification, then the system is more flexible and easier to maintain, but hardware replacement and software updates become necessary and complex
Solution Approach 1:
The standby process control apparatus automatically receives and processes the updated program and context data without requiring manual intervention during the critical update moment. The system performs self-service by automatically switching from the active to the standby apparatus when the update is complete, reducing the complexity of manual update procedures.
4Productivity
If the update target program is updated while the system is running, then continuous operation is maintained, but the update process becomes complex and time-consuming
Solution Approach 1:
The update process is segmented into preparation (on standby apparatus) and execution (switching to standby) phases. This segmentation allows the active apparatus to continue operating normally while the update is prepared in parallel on the standby apparatus, significantly reducing the actual downtime required for the update.
Data Source
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AI summary
A first process control apparatus in a process control system executes a non-update target program which is not an update target and an update target program which may be the update target, pauses the non-update target program based on a pause request from an outside, and transfers a context of the non-update target program to a second process control apparatus. The second process control apparatus in the process control system executes the non-update target program which is not the update target and an update target program after update, restores a context of the non-update target program by using the transferred context, initializes a context of the update target program, and causes the second program execution unit to resume the non-update target program and the update target program, based on a resuming request from the outside.